This review article provides a comprehensive examination of the most recent advances in research on nanoglasses, including the methods used to create these materials, their characteristics, and their diverse range of uses. An overview of the current trends in nanoglass research connects them to the Sustainable Development Goals, highlighting the current relevance of this topic. The process of manufacturing nanoglasses is explained in depth, highlighting advanced approaches such as inert gas condensation and severe plastic deformation, among other techniques. The prime focus of this review is on analyzing the various dimensions of nanoglass materials, including their structural dynamics and electrical configurations, and how these features contribute to their exceptional thermal stability and mechanical strength. The magnetic characteristics of nanoglasses are examined, highlighting their potential for driving innovation across multiple industries. The primary emphasis is on the biological usefulness of nanoglasses, specifically examining their bioactivity and interaction with biological components, and emphasizing their growing use in nanoscale biomedical applications. With regard to the practical applications of nanoglasses, there are specific discussions of their contributions to biological evaluation, wound healing, catalysis, and environmental sustainability. There is an emphasis on the durability and resistance of nanoglasses in these contexts. The comprehensive overview of nanoglasses provided in this article highlights their significance as revolutionary materials in fields of science and technology. The potential of nanoglasses to contribute to a future that is more sustainable and health oriented is indicated. The article ends by discussing the future directions for nanoglass research and looks forward to the promising possibilities for further investigation and innovation.
I. INTRODUCTION
Nanoglasses are materials made up of glassy regions that are nanometers in size and connected by low-density interfaces. The characteristics of nanoglasses can be adjusted by changing the chemical composition of the material or the microstructures of the faults.1 In addition to this, melt-quenched glasses have been shown to be less malleable, biocompatible, and catalytically active than nanoglasses.2 Thus, producing innovative materials that exploit the novel properties of this new category of noncrystalline materials is a useful endeavor. The ordering of atoms in any given substance can, to a significant degree, be deduced from the characteristics of that substance, and changes to the atomic structure of a material result in changes in the material’s properties itself. When the arrangement of the atoms is determined, it is possible to produce an entirely new class of materials with its own set of characteristics. In this review, techniques for synthesis and processing are discussed and compared with the process of compacting and sintering nanoparticles in nanocrystalline materials. In addition, the most recent research on the synthesis, characterization techniques, properties, and applications of various glasses is summarized.3–7
Throughout the course of history, the atomic structures of materials have been modified by using a variety of methods: the oldest method of modifying the atomic structure of crystalline materials can be traced back to the Bronze and Iron Ages, namely, the introduction of lattice defects into the crystal structure by forging.8 Interatomic spaces and symmetry are two aspects of the atomic structure that are noticeably distinct from each other in comparison with those of regular crystals that are free of defects. As a result, the characteristics of a flawed crystal and a flawless crystal differ. If the material is exposed to the highest possible defect density, its microstructure may undergo the most significant changes. Several studies of the maximum achievable defect density in a crystal, with severe plastic deformation, have revealed that up to 1% of the atoms are in the cores of the defects.8 Another method involves reducing crystal size. Noncrystalline materials comprise nanometer-sized crystals, with up to 50% of atoms positioned on the intercrystalline boundaries. Nanocrystalline materials fill the gap between noncrystalline and conventional coarse-grained materials. They are usually produced using melt-spinning processes through rapid solidification of a liquid. These nanocrystalline materials have unusually diverse properties. For instance, it has been reported that shrinking the crystal size to a few nanometers increases the diffusivity in metallic nanocrystalline Cu, Au, and Ni materials by more than 20 orders of magnitude. Figure 1 provides a systematic depiction of nanoglasses, illustrating their diverse uses, inherent characteristics, approaches to production, and methods for analysis.
Nanoglasses have a wide range of applications, such as in thermoelectric systems, in enhancing biomineralization processes, in tissue implantation, and in various other promising therapeutic applications. These applications highlight the significance of nanoglasses in both industrial and medical sectors. Nanoglasses exhibit remarkable thermal stability, mechanical characteristics, and improved magnetic properties, demonstrating their durability and versatile functionality. Nanoglass production entails the utilization of advanced techniques such as cluster ion beam deposition, pulsed laser deposition, severe plastic deformation, inert gas condensation, magnetron sputtering, and other irradiation methods. Each of these approaches implies a sophisticated manufacturing process. To analyze the characterization of these materials, advanced methods such as phase separation, Mössbauer spectroscopy, and magnetic Compton scattering are used to evaluate their structure and properties. Figure 1 presents a brightly colored, multilayered depiction of a nanoglass structure, representing its intricate nature and diverse range of uses.1–8
To produce a nanoglass, nanometer-scale interfaces are incorporated into a glass. The nanoglass interface is delocalized because of the annealing process applied to the material. As a direct consequence, the free volume combined with the interfaces is dispersed throughout the nanoglass volume. Because of this delocalization, the glass exhibits variations in both its atomic structure and density throughout its volume. In an analogous manner, the atomic structure of a nanoglass, and consequently its properties, can be modified by adjusting the distance between interfaces, as well as the delocalization process, in conjunction with varying the annealing time (3 h, 12 h, and 24 h) and temperature (350 °C).9
Gleiter2,8 suggested the addition of nanometer-scale interfaces to metallic, ionic, or covalent glasses to circumvent the restriction of further reduction in the minimum crystal size of nanocrystalline materials. In contrast to crystalline materials, the rapid melt quenching process to produce metallic glasses does not provide the flexibility to change their internal structure. This prevents metallic glasses from being structurally altered and gain better mechanical strength, diffusivity, and electrical properties. By contrast, with crystalline materials, structural modification is possible through control of their chemical microstructure, introduction of regulated lattice defects, or both. This harnessing of microstructural changes was not explored in metallic glasses before 1989, when Gleiter came up with the idea of subjecting amorphous nanoparticles to high uniaxial pressure so that they acquired a dense amorphous arrangement with interface defects between them.9
This review highlights the novelty of nanomaterials, emphasizing their potential to advance sustainability, technology, and biomedicine through synergistic effects. It offers an overview of the most recent methods for combining different materials, and how these methods are connected to the wide range of functions that nanoglasses can have. It evaluates the relationship between the structure and properties of nanoglasses, through advanced characterization techniques such as Mössbauer spectroscopy, with a focus on future applications. Additionally, it addresses the urgent need for environmentally acceptable and safe materials. This compilation of extensive research and innovative applications establishes nanoglasses as crucial materials in the pursuit of creative answers to modern challenges. The study highlights the growing compatibility and activity of nanoglasses in biological systems, indicating promising opportunities for their use in biomedical applications.
II. RECENT TRENDS IN NANOGLASS RESEARCH
A. Scientific progress and SDG mapping of documentation
Scientific advances in the field of nanoglasses have contributed to their potential for replacing other materials that are currently in use. Healthcare products and gadgets fabricated from plastics, steel, or other materials can be dangerous or expensive. Nanoglass is inert, and so unlike plastic, it will not be dangerous to wildlife if swallowed, and it will disintegrate naturally over time. Nanoglasses are more environmentally benign than steel and other materials, and their products have a long life cycle, reducing consumption and waste. Therefore, nanoglass is a better material for a number of Sustainable Development Goals (https://sdgs.un.org/goals): SDG 3 (Good Health and Well-Being), SDG 13 (Climate Action), and SDG 12 (Responsible Consumption and Production). Nanoglass materials outperform plastics and other costlier materials in terms of climate neutrality.
Figure 2 comprises a collection of visual depictions that provide a concise overview of scholarly papers pertaining to “nanoglass” as retrieved from Scopus on March 8, 2024.10 Figure 2(a) is a line graph illustrating the annual count of published documents from 1989 to 2023. The data points are indicated by crimson dots, and there is a significant surge in publications through time, particularly a steep ascent after the year 2000, reaching its highest point around 2020 with a total of 30 documents. Figure 2(b) is a composite visualization that combines a bar graph and a map to present the distribution of documents according to country. China is the frontrunner with more than 250 records, while Germany, the United States, and India all have less than 100 documents. The map is chromatically classified to align with the quantity of publications, illustrating the worldwide dispersion of research effort on “nanoglass.”12
The largest bubble is for SDG 3 (Good Health and Well-Being), with smaller circles labeled 3.2, 3.4, and 3.d highlighting specific targets. With a big bubble but no targets, SDG 13 (Climate Action) is important. SDGs 12 (Responsible Consumption and Production) and 15 (Life on Land) have smaller bubbles than SDGs 3 and 13, showing a reduced but still significant concentration. The smallest bubble, SDG 9 (Industry, Innovation, and Infrastructure), contains a target 9.5 in a tiny circle, potentially emphasizing that target.
Figure 2(c) is a pie chart that provides a detailed breakdown of the various sorts of documents that were published. There are 213 articles, 27 conference papers, 13 reviews, 5 book chapters, and a few other types of work. Figure 2(d) is a pie chart illustrating the allocation of papers according to their subject area. Materials Science has the most representation with 193 documents, followed by Physics and Astronomy with 132, and Engineering with 112. The research on “nanoglass” demonstrates its interdisciplinary nature, as evidenced by the very limited number of documents in several other subject areas (1–3). The present paper has been consolidated and analyzed using the SDG mapper tool. Figure 2(e) shows how the mapping tool appraised its relevance: it is most relevant to SDG 3 (Good Health and Well-being) with 46.2% and SDG 13 (Climate Action) with 30.8%. SDG 9 (Industry, Innovation, and Infrastructure), SDG 12 (Responsible Consumption and Production), and SDG 15 (Life on Land) are represented by three equal-height bars with 7.7% relevance. Figure 2(f) shows a bubble chart of the SDGs and their Targets.
B. Advances in nanoglass synthesis, properties, and applications
Nanoglass technology has made great progress in terms of synthetic procedures, resulting in improved characteristics and a wide range of uses. This has established nanoglasses as revolutionary materials in multiple industries. Nanoglasses are created using advanced techniques such as sol–gel procedures and nanoimprinting to achieve exceptional mechanical strength and resistance to scratches, as well as distinctive optical properties. The exceptional qualities of this material have made it highly sought after for advanced applications, including state-of-the-art uses in electronics, photonics, biomedical devices, solar cells, and energy storage systems. Ongoing research in nanoglass technology is expanding its potential uses in protective coatings and hybrid materials, leading to advances in material science and technology.14–20 Table I presents a comprehensive overview of the progress made in nanoglass technology, specifically highlighting the techniques used for synthesis, the improved characteristics achieved, and the latest innovative uses.
Nanoglass . | Functionality . | Applications . | References . |
---|---|---|---|
Fe90Sc10 | Mechanical strength, high plasticity | Aerospace and automotive components | 7 |
SiO2–P2O5 single bond CaO–SrO–Ag2O–ZnO | Antibacterial activity, biocompatibility, bioactivity | Orthopedic | 14 |
Ce65Al10Co25 | Two-way structural tuning | Memory, sensors, actuators | 15 |
Au40Cu28Ag7Pd5Si20 | Adjustable porosity, enhanced electromagnetic fields | Biosensors for medical diagnostics | 16 |
Cu–Ti | Distinct interfaces, room-temperature creep resistance, anomalously negative strain rate sensitivity | Microelectromechanical systems (MEMS), nanoelectromechanical systems (NEMS) | 17 |
P2O5–CaO | Lack of unknown metabolizable ions, enhanced bioactive calcium ion release | Advanced biomedical activity | 18 |
Zr–Pd | Thermal stability, high corrosion resistance, catalytic activity, and biocompatibility | Biomedical implants devices | 19 |
LiFeSi2O6 | Enhanced reactivity via mechanical pre-activation | Advanced battery technologies | 20 |
Zr55.7Ni10Al7Cu19Co8.3 | Biocompatibility and mechanical integrity | Aerospace, automotive, tissue engineering scaffolds, drug delivery systems | 21 |
SiO2–CaO–Na2O–P2O5 | Efficient myogenic differentiation and improved skeletal muscle tissue regeneration | Biomedicine, drug delivery, gene therapy | 22 |
Ni–P | Controlled rate of cluster formation and cluster growth | Electrochemical devices | 23 |
Li2O–SiO2 | Reduced resistivity, lower activation energy | Advanced electronic devices, ionic transport systems | 24 |
Fe79B21 | Reduced hyperfine fields, higher degree of disorder | Data storage, magnetic sensors, spintronic devices | 25 |
ZrO2–Cu | High transmittance, high refractive index, large optical bandgap | Optoelectronic devices | 26 |
CuZr | Excess free volume distribution | Material design and engineering | 27 |
Al2Si2O5(OH)4 | Enhanced mechanical properties, thermal stability, high-temperature resistance | Building applications, industrial furnaces | 28 |
Nanoglass . | Functionality . | Applications . | References . |
---|---|---|---|
Fe90Sc10 | Mechanical strength, high plasticity | Aerospace and automotive components | 7 |
SiO2–P2O5 single bond CaO–SrO–Ag2O–ZnO | Antibacterial activity, biocompatibility, bioactivity | Orthopedic | 14 |
Ce65Al10Co25 | Two-way structural tuning | Memory, sensors, actuators | 15 |
Au40Cu28Ag7Pd5Si20 | Adjustable porosity, enhanced electromagnetic fields | Biosensors for medical diagnostics | 16 |
Cu–Ti | Distinct interfaces, room-temperature creep resistance, anomalously negative strain rate sensitivity | Microelectromechanical systems (MEMS), nanoelectromechanical systems (NEMS) | 17 |
P2O5–CaO | Lack of unknown metabolizable ions, enhanced bioactive calcium ion release | Advanced biomedical activity | 18 |
Zr–Pd | Thermal stability, high corrosion resistance, catalytic activity, and biocompatibility | Biomedical implants devices | 19 |
LiFeSi2O6 | Enhanced reactivity via mechanical pre-activation | Advanced battery technologies | 20 |
Zr55.7Ni10Al7Cu19Co8.3 | Biocompatibility and mechanical integrity | Aerospace, automotive, tissue engineering scaffolds, drug delivery systems | 21 |
SiO2–CaO–Na2O–P2O5 | Efficient myogenic differentiation and improved skeletal muscle tissue regeneration | Biomedicine, drug delivery, gene therapy | 22 |
Ni–P | Controlled rate of cluster formation and cluster growth | Electrochemical devices | 23 |
Li2O–SiO2 | Reduced resistivity, lower activation energy | Advanced electronic devices, ionic transport systems | 24 |
Fe79B21 | Reduced hyperfine fields, higher degree of disorder | Data storage, magnetic sensors, spintronic devices | 25 |
ZrO2–Cu | High transmittance, high refractive index, large optical bandgap | Optoelectronic devices | 26 |
CuZr | Excess free volume distribution | Material design and engineering | 27 |
Al2Si2O5(OH)4 | Enhanced mechanical properties, thermal stability, high-temperature resistance | Building applications, industrial furnaces | 28 |
Figure 3 provides a comprehensive overview of nanoglass use, focusing on the creation and analysis of bioactive nanoglass materials and emphasizing their potential use in biomedicine. There are many combinations of nanoglass powders, and the results of fluorescence microscopy suggest that these combinations have positive effects on biological cells. Thermal investigation uncovers distinct transition temperatures, indicating suitability and durability for biological applications. Stress–strain curves provide a visual representation of a material’s strength and elasticity, while scanning electron microscope (SEM) images show how the material’s structure remains intact even when deformed. X-ray photoelectron spectroscopy (XPS) provides a comprehensive analysis of the elemental composition and chemical states of materials, which is crucial for gaining insights into molecular-level interactions. Confocal imaging conducted over a period of two weeks has revealed continuous cellular activity on nanoglass material, indicating its ability to interact well with living cells and suggesting its potential as a highly favorable option for biomedical devices or tissue engineering applications.7,15,19,20
Bioactive glass nanoparticles (BGNs) are utilized in a range of biomedical applications, including drug delivery, gene therapy, tumor treatment, bioimaging, identification of molecular markers, and tissue engineering.19,20 Myogenic differentiation in C2C12 cells has shown that BGN chemical composition significantly affects myotube formation and myogenic gene expressions. 80Si-BGN (chemical composition 80SiO2–16CaO–4P2O5) enhanced myogenic differentiation more than 60Si-BGN (60SiO2–36CaO–4P2O5) and 100Si-BGN (100SiO2).22 That study found that the right silicon–calcium ratio improved myogenic differentiation and skeletal muscle regeneration. In vivo experiments in rats with skeletal muscle defects showed that 80Si-BGN could significantly improve skeletal muscle tissue regeneration for four weeks.22
Nanoglass particles appear as strongly agglomerated clusters of 40–65 nm in the transmission electron microscope images on the left of Fig. 3(a). Dehydration of calcium silicate hydrate (CSH) and matrix binding phases causes most samples to turn white at 800 °C, as can be seen on the right of Fig. 3(a). Figure 3(b) shows the evaluation of myogenic differentiation in C2C12 cells employing 100Si-BGN and an in vivo assessment of tibialis anterior muscle insufficiency and skeletal tissue regeneration in rats after one week. Figure 3(c) shows the differential scanning calorimetry (DSC) curve of a Ce65Al10Co25 metallic glass sample, which was heated from 330 to 625 K at a rate of 10 K/min. The initial exothermic peak is detected at roughly 428 K, followed by three complex reactions at around 483 K. The combination of temperature and pressure allows two-way structural tuning to dramatically ordered and disordered states far beyond nearest-neighbor shells, extending metallic glass states to unexplored configuration spaces.7 Mechanical properties of a nanoglass–nanocrystal composite were tested using 1 µm diameter pillars in micropillar compression testing [Fig. 3(d)]. The true stress–strain curve shows a 2.5 GPa yield strength, one of the highest values ever observed for Fe-based alloys, including steels, and twice as high as Sc-rich Sc75Fe25 nanoglass.7 Magnetron sputtering of Zr and Pd powder mixtures produces hierarchical nanoscale Zr–Pd metallic glassy thin films with unique physical and biochemical properties. Catalytic activity and biocompatibility experiments show that nanostructured metallic glass is ideal for biochemical applications.19 The high catalytic activity of crystalline Pd is well known. We assume that a glassy sample with high catalytic activity contains as much Pd as possible. Only at 46% Zr (and above) does the sputtered thin film become fully amorphous [Fig. 3(e)]. A biocompatibility test showed that osteoblast cells were deposited on Zr–Pd nanoglass films with pure Ti plates as substrates and on pure Ti sheets for comparison.19 On day 7, Ti and nanoglass-grown osteoblasts were stained with TRITC–phalloidin and DAPI for cytoskeleton organization and cell nucleus analysis. Osteoblasts adhered well to Ti and Zr–Pd nanoglass. Subsequently, the activity of alkaline phosphatase (ALP), an important enzyme produced by osteoblasts and an early marker for osteogenesis, and the secretion of osteocalcin, the main noncollagenous protein involved in bone mineralization, were quantified.19 Nanoglass improves the mechanical, physical, and firing stability (mineralogical properties) of geopolymer composites. The effect of nanoglass powder on physicomechanical properties and firing stability at 500–1000 °C of geopolymer composite materials have been studied.20 The study found that geopolymer mixtures with up to 7% nanoglass powder had higher compressive strengths than control mixtures, but the strengths then decreased at contents of 9%–20%.
C. Simulation and characterization techniques
Numerous characterization methods are essential for understanding the material properties of nanoglasses, as illustrated in Fig. 4. High-energy spectroscopy reveals atomic structure and electrical characteristics, whereas electrodeposition shows surface morphology and coating uniformity. Thermal analysis examines phase transitions and stability during crystallization. Cryogenic and magnetic characterization show how severe temperatures and magnetic fields affect materials. Real-time monitoring and x-ray diffraction (XRD) are used to check metallic nanoglass structure crystallinity and flaws during fabrication. Fluorescence and luminescence spectroscopy investigate optical characteristics and energy band structures. Finally, computational molecular simulations predict nanoglass physical reactions under diverse conditions, completing a rigorous and multidimensional approach to nanoglass characterization.29–75
Studying nanoglass features, structures, composites, and magnetic properties helps understand relaxation, microstructure, crystallization, photonic engineering, plasticity, ultrastability, thermal, fabrication, and deformation behavior.29–42 Energy-related nanoglass research includes luminescence, emission, fluorescence, XRD, lasers, structural methods such as strength, ductility, deformation, shear band constraint, and indentation testing, and temperature-related studies such as densification, conductivity, and cryogenics. These help understand atomic-level structural stability, interface behavior, and treatment mechanisms.43–60 Structural analysis of metallic nanoglasses shows that atomic-level structural modifications, microstructure formation, plastic deformation, and alteration of mechanical properties by tailoring interface structure can provide unique functionalities.61–65 Composition, mechanical properties, strain delocalization through interfacial plasticity, molecular dynamics, shear band instability, heterogeneities, fracture variation, enhanced plasticity, glass development, and mechanical deficiencies have all been investigated in metallic nanoglasses.66–72 Electrical resistivity, electrodeposition, and the role of free electrons are all examples of important properties that affect the mechanism of formation of Fe50B50, Sc75Fe25, and FeCoP nanoglass films.73–75
D. Mössbauer spectroscopy
The results of the Mossbauer spectroscopy performed on Fe90Sc10 nanoglass reveal two separate structures, which are referred to as the core and the shell and confirm that there is a variation in the atomic and electronic configuration of the nanoglass samples in this case. The same structural variation has also been reported in other nanoglasses, such as Pd72Fe10Si18,35 Fe90Sc10,36 Fe50B50,25 and some ScFe nanoglasses.2 Jing et al.34 used Mossbauer spectroscopy to investigate the atomic structure of a Pd70Fe3Si27 nanoglass. They discovered that the microstructure of the nanoglass sample was significantly different from that of a melt-spun glass. The melt-spun Pd72Fe10Si18 glass and nanoglass have identical chemical compositions, as shown in Fig. 5 by their Mössbauer spectra and quadrupole splitting (QS, right side). The melt-spun glass had one peak in the QS distribution at 0.4 mm/s, while the nanoglass had two peaks, the first of which was also at 0.4 mm/s, while the second peak, corresponding to the glass–glass interface, was at 0.9 mm/s.
Understanding the different forms of nanoglass is critical for their production and characterization procedures. Table II lists types of nanoglass, together with their characterization methods, and their characteristics. It illustrates the complexity and richness of nanoglass research through the wide range of characterization methods used, revealing the unique properties and prospective uses of nanoglass materials.
Type of nanoglass . | Synthesis/fabrication method . | Characterization techniques . | References . |
---|---|---|---|
Ni–P | Pulse electrodeposition | X-ray diffraction (XRD), Transmission electron microscopy (TEM) | 29 and 30 |
BiO3 | Dry milling | In situ TEM | 40 |
Tm3+/Yb3+/Nd3+ | Melt quenching | Up-conversion luminescence spectroscopy, absorption spectroscopy | 43 |
Si–N | Laser-driven gas-phase reactions | Fourier transform infrared spectroscopy (FTIR), XRD | 44 |
PdFeSi | Inert gas condensation | Extended x-ray absorption fine structure (EXAFS), TEM | 45 |
Ni50Ti45Cu5 | Magnetron sputtering | TEM, scanning electron microscopy (SEM), Energy-dispersive x-ray spectroscopy (EDS) | 46 |
Pd–Si | Inert gas condensation | SEM, TEM, nanoindentation | 47 |
La–Ga–S–O–Gd | Melt quenching | Laser scanning microscopy, birefringence measurements | 48 |
Ga2O3:Ni | Melt quenching | Photoluminescence spectroscopy, electron energy loss spectroscopy (EELS) | 49 |
Cu64Zr36 | Melt quenching | TEM, XRD, mechanical testing | 50 |
Lithium silicate | Sol–gel | Electrochemical impedance spectroscopy (EIS), solid state nuclear magnetic resonance (NMR) | 51 |
Cu–Zr | Melt quenching | TEM, molecular dynamics simulation (MDS), mechanical creep testing | 52 |
Tb75Fe25 | Inert gas condensation | Magnetometry, cryogenic testing, TEM | 53 |
CuZr | Melt quenching | SEM, TEM, nanoindentation | 54 |
Cu–Zr | Magnetron sputtering | Nanoindentation, TEM, SEM | 56 |
CsPbBr3 | Vapor drop-casting technique | Photoluminescence spectroscopy, absorption spectroscopy | 57 |
Fe90Sc10 | Melt spinning and melt quenching | X-ray absorption spectroscopy (XAS), high-energy XRD (HEXRD) | 58 and 59 |
Sc75Fe25 | Inert gas condensation | High-resolution TEM (HRTEM), XRD | 60 |
Fe50B50 | Conventional chemical process | High-angle annular dark field (HAADF) STEM, TEM | 73 |
Sc75Fe25 | Inert gas condensation | Four-point probe measurement, TEM, mechanical testing | 74 |
FeCoP films | Electrodeposition | Cyclic voltammetry, scanning electrochemical microscopy (SECM) | 75 |
Type of nanoglass . | Synthesis/fabrication method . | Characterization techniques . | References . |
---|---|---|---|
Ni–P | Pulse electrodeposition | X-ray diffraction (XRD), Transmission electron microscopy (TEM) | 29 and 30 |
BiO3 | Dry milling | In situ TEM | 40 |
Tm3+/Yb3+/Nd3+ | Melt quenching | Up-conversion luminescence spectroscopy, absorption spectroscopy | 43 |
Si–N | Laser-driven gas-phase reactions | Fourier transform infrared spectroscopy (FTIR), XRD | 44 |
PdFeSi | Inert gas condensation | Extended x-ray absorption fine structure (EXAFS), TEM | 45 |
Ni50Ti45Cu5 | Magnetron sputtering | TEM, scanning electron microscopy (SEM), Energy-dispersive x-ray spectroscopy (EDS) | 46 |
Pd–Si | Inert gas condensation | SEM, TEM, nanoindentation | 47 |
La–Ga–S–O–Gd | Melt quenching | Laser scanning microscopy, birefringence measurements | 48 |
Ga2O3:Ni | Melt quenching | Photoluminescence spectroscopy, electron energy loss spectroscopy (EELS) | 49 |
Cu64Zr36 | Melt quenching | TEM, XRD, mechanical testing | 50 |
Lithium silicate | Sol–gel | Electrochemical impedance spectroscopy (EIS), solid state nuclear magnetic resonance (NMR) | 51 |
Cu–Zr | Melt quenching | TEM, molecular dynamics simulation (MDS), mechanical creep testing | 52 |
Tb75Fe25 | Inert gas condensation | Magnetometry, cryogenic testing, TEM | 53 |
CuZr | Melt quenching | SEM, TEM, nanoindentation | 54 |
Cu–Zr | Magnetron sputtering | Nanoindentation, TEM, SEM | 56 |
CsPbBr3 | Vapor drop-casting technique | Photoluminescence spectroscopy, absorption spectroscopy | 57 |
Fe90Sc10 | Melt spinning and melt quenching | X-ray absorption spectroscopy (XAS), high-energy XRD (HEXRD) | 58 and 59 |
Sc75Fe25 | Inert gas condensation | High-resolution TEM (HRTEM), XRD | 60 |
Fe50B50 | Conventional chemical process | High-angle annular dark field (HAADF) STEM, TEM | 73 |
Sc75Fe25 | Inert gas condensation | Four-point probe measurement, TEM, mechanical testing | 74 |
FeCoP films | Electrodeposition | Cyclic voltammetry, scanning electrochemical microscopy (SECM) | 75 |
E. Functional diversity of nanoglasses
Owing to their potential to combine the benefits of glasses and crystalline materials, nanoglasses, as a type of nanocrystalline materials with a glass-like nanostructure, have extraordinary functional variety. Nanoglasses provide superior mechanical strength, elasticity, electrical, and thermal conductivity compared with normal glasses or crystalline materials because to this duality. Their huge surface area and many interfaces make them candidates for catalysis, energy storage, and biological applications where surface interactions and reactivity are important. Nanoglasses are promising materials for many technological applications owing to their versatility and adjustable characteristics.7,8,14–19,76
The pollution caused by micro- and nanoglasses is expected to become an emerging problem in the near future, and consequently additional research on hazardous properties and technological approaches to dealing with these will be required at regular intervals for the purpose of ensuring global sustainability.13,19,77 By introducing glass–glass interfaces and delocalizing interfaces to varying degrees, depending on the annealing time and temperature,8 it is possible to change the atomic structure and properties of glasses, which are dependent on their free volume. The delocalization process creates glasses with free volumes and tunable atomic structures. Adjusting the spacing between interfaces in nanoglasses controls their delocalization (atomic structures and density).8 An examination of the structural characteristics of nanoglass models produced through cold compression reveals that face-centered cubic packing models of nanoglass undergo a transformation into spherical nanoparticles.77 According to the findings of this study, the glass–glass interfaces associated with nanoglasses prepared using inert gas condensation are more substantial and exhibit a greater degree of structural contrast in comparison with their parent metallic glass structure. Table III presents various nanoglasses and their structural and chemical characteristics. It details how these materials outperform traditional ones in mechanical strength, thermal stability, and magnetic properties, as well as indicating the possible uses of nanoglasses in materials science and suggesting how they could help develop new technologies or improve existing ones.31,78–109
Type of nanoglass . | Features and properties . | Prospective uses . | References . |
---|---|---|---|
Iron-based | Ferromagnetism enhancement | Iron-based nanoglass exhibits enhanced ferromagnetic properties, promising for various applications in magnetism-related technologies. | 31 |
TiZrPdCu, TiZrPdCuBi | Microstructure, mechanical and thermal | The combination of titanium, zirconium, palladium, and copper in nanoglasses results in improved mechanical strength and thermal stability, opening avenues for advanced engineering applications. | 79 |
Cu64Zr36, Pd80Si20 | Mechanical strength | Nanoglasses with homogeneous bulk structure display exceptional mechanical strength, indicating their potential in structural materials with high durability requirements. | 80 |
Fe-based | Effective noble-metal-free electrocatalyst | Iron-based nanoglass demonstrates promising electrocatalytic activity without the need for noble metals, offering sustainable solutions in catalysis and energy conversion devices. | 81 |
CuZr | Microstructural effects on dynamical relaxation | The microstructural composition of nanoglass composites influences dynamical relaxation behavior, paving the way for tailored materials with tunable mechanical properties. | 82 |
NiO–SiO2 | Magnetodielectric behavior | Nanoglasses composed of nickel oxide and silicon dioxide exhibit unique magnetodielectric properties, showcasing their potential in multifunctional device applications. | 83 |
Nd3+ doped tellurite | Thermal and photoluminescence properties | Nanoglasses doped with neodymium tellurite exhibit distinct thermal and photoluminescence characteristics, suggesting their utility in optoelectronic and thermal sensing applications. | 84 |
Palm oil-based trimethylolpropane | Wear and friction behavior | Powder nanoglasses display altered wear and friction behavior, offering opportunities for enhancing the durability of materials in abrasive environments. | 85 |
PET-based micro- and nanoglass flakes | Physical, mechanical, and thermal | Flake nanoglasses demonstrate versatile physical, mechanical, and thermal properties, making them suitable for diverse applications ranging from coatings to electronic devices. | 86 |
Ni60Nb40 | Tunable magnetism and methanol oxidation | Nickel–niobium nanoglasses exhibit tunable magnetism and catalytic activity for methanol oxidation, presenting opportunities in magnetic and energy storage technologies. | 87 |
Al-based metallic | The mechanical properties enhanced significantly | Aluminum-based nanoglasses exhibit significantly enhanced mechanical properties, indicating their potential for lightweight structural applications with high strength requirements. | 88 |
Cu64Zr36 | Strength, hardness, and ductility | Copper–zirconium nanoglasses offer improved strength, hardness, and ductility, making them promising candidates for structural materials demanding a balance of mechanical properties. | 89 |
U-based thin film | Microstructure and electrochemical properties | Uranium-based thin-film nanoglasses influence microstructure and electrochemical behavior, suggesting their potential in electrochemical sensing and energy storage applications. | 90 |
Mg65Ce10Ni20Cu5 | Hydrogenation properties | Magnesium–cerium–nickel–copper nanoglasses exhibit specific hydrogenation properties, offering opportunities for hydrogen storage and purification applications. | 91 and 92 |
CoO.SiO2–ZnO | Electrical conductivity and magnetodielectric effect. | Cobalt oxide–silicon dioxide–zinc oxide nanoglasses exhibit dual electrical conductivity and magnetodielectric effects, showing potential in multifunctional electronic devices. | 93 |
Sc-based | Plasticity | Scandium-based nanoglasses influence material plasticity, offering opportunities for tailoring mechanical properties in structural materials with enhanced formability. | 94 |
Au-based | Ultra-stable kinetic behavior | Gold-based nanoglasses demonstrate exceptionally stable kinetic behavior, suggesting their utility in high-temperature and high-pressure environments where stability is critical. | 95 |
Metallic | Tunable mechanical properties and thermal and plastic behavior; promote β-relaxation and tensile plasticity | Metallic nanoglasses offer versatile influence on mechanical, thermal, and plastic properties, enabling tailored materials for various engineering applications. | 96–99 |
Ti-based | Modulate osteoblast behavior | Titanium-based nanoglasses modulate osteoblast behavior, indicating their potential in biomedical applications such as bone tissue engineering and regenerative medicine. | 100 |
Pb-free | Silicon solar cells | Lead-free nanoglasses show promise in silicon solar cells, offering environmentally friendly alternatives for photovoltaic applications. | 101 |
Sc79 Fe21 Sc75Fe25 | Magnetic properties | Scandium–iron nanoglasses contribute to magnetic properties, providing opportunities for magnetic and sensor applications in diverse fields. | 102 and 103 |
Al–N | Super-ductility | Aluminum–nitrogen nanoglasses exhibit super-ductility, suggesting their utility in applications requiring materials with exceptional toughness and deformability. | 104 |
Cu–Zr | Dynamic responses | Copper–zirconium nanoglasses influence dynamic responses, offering opportunities for dynamic materials with tailored mechanical behavior. | 105 |
Pd–Si | Thermal and mechanical properties | Palladium–silicon nanoglasses have useful thermal and mechanical properties, showing potential for use in high-temperature and high-stress environments. | 106 |
Yb oxyfluoride | Laser cooling | Ytterbium oxyfluoride nanoglasses demonstrate laser cooling properties, offering possibilities for efficient thermal management in optical and photonics applications. | 107 |
Fe2O3.SiO2 | Large magnetodielectric effect | Iron oxide–silicon dioxide nanoglasses exhibit a significant magnetodielectric effect, showing promise for multifunctional device applications requiring coupled magnetic and electric responses. | 108 |
Type of nanoglass . | Features and properties . | Prospective uses . | References . |
---|---|---|---|
Iron-based | Ferromagnetism enhancement | Iron-based nanoglass exhibits enhanced ferromagnetic properties, promising for various applications in magnetism-related technologies. | 31 |
TiZrPdCu, TiZrPdCuBi | Microstructure, mechanical and thermal | The combination of titanium, zirconium, palladium, and copper in nanoglasses results in improved mechanical strength and thermal stability, opening avenues for advanced engineering applications. | 79 |
Cu64Zr36, Pd80Si20 | Mechanical strength | Nanoglasses with homogeneous bulk structure display exceptional mechanical strength, indicating their potential in structural materials with high durability requirements. | 80 |
Fe-based | Effective noble-metal-free electrocatalyst | Iron-based nanoglass demonstrates promising electrocatalytic activity without the need for noble metals, offering sustainable solutions in catalysis and energy conversion devices. | 81 |
CuZr | Microstructural effects on dynamical relaxation | The microstructural composition of nanoglass composites influences dynamical relaxation behavior, paving the way for tailored materials with tunable mechanical properties. | 82 |
NiO–SiO2 | Magnetodielectric behavior | Nanoglasses composed of nickel oxide and silicon dioxide exhibit unique magnetodielectric properties, showcasing their potential in multifunctional device applications. | 83 |
Nd3+ doped tellurite | Thermal and photoluminescence properties | Nanoglasses doped with neodymium tellurite exhibit distinct thermal and photoluminescence characteristics, suggesting their utility in optoelectronic and thermal sensing applications. | 84 |
Palm oil-based trimethylolpropane | Wear and friction behavior | Powder nanoglasses display altered wear and friction behavior, offering opportunities for enhancing the durability of materials in abrasive environments. | 85 |
PET-based micro- and nanoglass flakes | Physical, mechanical, and thermal | Flake nanoglasses demonstrate versatile physical, mechanical, and thermal properties, making them suitable for diverse applications ranging from coatings to electronic devices. | 86 |
Ni60Nb40 | Tunable magnetism and methanol oxidation | Nickel–niobium nanoglasses exhibit tunable magnetism and catalytic activity for methanol oxidation, presenting opportunities in magnetic and energy storage technologies. | 87 |
Al-based metallic | The mechanical properties enhanced significantly | Aluminum-based nanoglasses exhibit significantly enhanced mechanical properties, indicating their potential for lightweight structural applications with high strength requirements. | 88 |
Cu64Zr36 | Strength, hardness, and ductility | Copper–zirconium nanoglasses offer improved strength, hardness, and ductility, making them promising candidates for structural materials demanding a balance of mechanical properties. | 89 |
U-based thin film | Microstructure and electrochemical properties | Uranium-based thin-film nanoglasses influence microstructure and electrochemical behavior, suggesting their potential in electrochemical sensing and energy storage applications. | 90 |
Mg65Ce10Ni20Cu5 | Hydrogenation properties | Magnesium–cerium–nickel–copper nanoglasses exhibit specific hydrogenation properties, offering opportunities for hydrogen storage and purification applications. | 91 and 92 |
CoO.SiO2–ZnO | Electrical conductivity and magnetodielectric effect. | Cobalt oxide–silicon dioxide–zinc oxide nanoglasses exhibit dual electrical conductivity and magnetodielectric effects, showing potential in multifunctional electronic devices. | 93 |
Sc-based | Plasticity | Scandium-based nanoglasses influence material plasticity, offering opportunities for tailoring mechanical properties in structural materials with enhanced formability. | 94 |
Au-based | Ultra-stable kinetic behavior | Gold-based nanoglasses demonstrate exceptionally stable kinetic behavior, suggesting their utility in high-temperature and high-pressure environments where stability is critical. | 95 |
Metallic | Tunable mechanical properties and thermal and plastic behavior; promote β-relaxation and tensile plasticity | Metallic nanoglasses offer versatile influence on mechanical, thermal, and plastic properties, enabling tailored materials for various engineering applications. | 96–99 |
Ti-based | Modulate osteoblast behavior | Titanium-based nanoglasses modulate osteoblast behavior, indicating their potential in biomedical applications such as bone tissue engineering and regenerative medicine. | 100 |
Pb-free | Silicon solar cells | Lead-free nanoglasses show promise in silicon solar cells, offering environmentally friendly alternatives for photovoltaic applications. | 101 |
Sc79 Fe21 Sc75Fe25 | Magnetic properties | Scandium–iron nanoglasses contribute to magnetic properties, providing opportunities for magnetic and sensor applications in diverse fields. | 102 and 103 |
Al–N | Super-ductility | Aluminum–nitrogen nanoglasses exhibit super-ductility, suggesting their utility in applications requiring materials with exceptional toughness and deformability. | 104 |
Cu–Zr | Dynamic responses | Copper–zirconium nanoglasses influence dynamic responses, offering opportunities for dynamic materials with tailored mechanical behavior. | 105 |
Pd–Si | Thermal and mechanical properties | Palladium–silicon nanoglasses have useful thermal and mechanical properties, showing potential for use in high-temperature and high-stress environments. | 106 |
Yb oxyfluoride | Laser cooling | Ytterbium oxyfluoride nanoglasses demonstrate laser cooling properties, offering possibilities for efficient thermal management in optical and photonics applications. | 107 |
Fe2O3.SiO2 | Large magnetodielectric effect | Iron oxide–silicon dioxide nanoglasses exhibit a significant magnetodielectric effect, showing promise for multifunctional device applications requiring coupled magnetic and electric responses. | 108 |
Nanoglass materials have many features and uses, as can be seen in Fig. 6, in which mechanical, thermal, electrical, and magnetic qualities radiate from the center, including various kinds of nanoglass like “TiZrPdCu” and “Fe-based,” which have higher “ferromagnetism enhancement” or “mechanical strength.” According to the theme bubbles such as those labeled “Magnetodielectric” and “Wear and friction behavior,” the qualities are relevant to fields such as tissue engineering, pollution management, and sensor device technology. This graphic structure emphasizes nanoglasses’ adaptability and vast range of uses, indicating their importance in materials science and technology.31,78–109
Owing to their unique two-phase interior architecture, nanoglasses have several unusual properties. This suggests that more research is needed to understand their microstructure and features. Nanoglass interfacial regions have almost 10% less density and 20% fewer near-neighbor atoms than melt-quenched glasses, allowing for a different electronic structure.110 Nanoglasses are classified by integral atomic constituents and glass system characteristics such as metallic and oxide.110 However, AC electrical behavior and an absence of isothermal nucleation indicate crystallization on modified phosphate glass.111 The significance of nanoglasses for biological applications could be increased by improving their functional and technological aspects.
F. Roadmap of evolution
Advances in nanoglass research include a variety of previous and current technical initiatives. These have enabled the successful development of new nanomaterials by providing a number of technological insights. Figure 7 is a graphical representation of the development of nanoglass materials over the course of the last 40 years. It presents the numerous varieties of nanoglasses that have been developed and the key aspects of their evolution in terms of synthesis, properties, application, and modifications to provide new functionalities.91–97
Integration of technological functionalities such as biocompatibility, sensing, optical, electronic, and magnetic properties acts as a driving force for advanced application development. Even though material nanoengineering holds great promise for a wide variety of technological applications, there are still challenges to be overcome. In this review, the current state-of-the-art synthetic and characterization techniques, properties, applications, and prospects of various glasses are examined using evidence from the most recent relevant literature. The biomineralization of nanoglasses and their advanced properties should pave the way for new frontiers in the technology of nanoscale devices.112–114
III. ADVANCED SCIENTIFIC METHODS
The production of nanoglasses involves advanced scientific methods, each tailored to manipulate the material’s structure and properties at the nanoscale. These methods are described in this section.
A. Inert gas condensation
The inert gas condensation (IGC) procedure is a well-established and indeed the very first method for synthesizing metallic nanoglasses.26,27 Thermal evaporation of the alloy takes place under an inert gas atmosphere, producing nanoparticles in a size range of 5–20 nm. The size can be controlled by parameters such as the total pressure of the inert gas, the partial pressure of the evaporating alloy, and the type of inert gas. The resulting nanoparticles are collected in a liquid-nitrogen-cooled cylinder through the convective inert gas flow from the hot source. Finally, the nanoparticulate powders are passed into an in situ vacuum chamber at a pressure of up to 2 GPa and can be further compressed in an ex situ compaction device. A variety of nanoparticles of different alloys can be processed using IGC.26,27 For example, Chen et al.5 synthesized nanoglass specimens comprising two components, Cu64Sc36 and Fe90Sc10. The recently reported nanoglasses from binary alloys include Ti–Pd and Au–La, Cu–Zr,114 Sc–Fe,115 and Fe–Sc.116 Thus, it is possible to tune the properties of new nanomaterials by adjusting the volume fraction of alloy particles.117 The density of nanoglasses produced by this method can be up to 87% of that of the corresponding crystalline compound, and this can be further increased up to 92% by subsequently compressing the nanoglass pellets at high pressures of 4–5 GPa.9
B. Magnetron sputtering, pulsed laser deposition, and irradiation
Laser ablation and magnetron sputtering are two alternatives to thermal evaporation for the generation of nanoparticles. Mohri et al.118 deposited nano-grained Ti–Zr–Cu–Pd metallic glass thin films using DC magnetron sputtering on an Si substrate at room temperature. They explored the impact of sputtering parameters (mainly DC power and sputtering pressure) on chemical composition and microstructure. Variations in composition were attributed to kinetic energy dissipation from interatomic collisions under different sputtering pressures (0.2–0.8 Pa) and powers (100 or 200 W). Low-pressure, high-power sputtering had little effect on target and film compositions. XRD and HRTEM showed amorphous structures with melt-quenched ribbon-like films formed at low Ar pressure. Films at higher Ar pressure had nanoglass-like glassy clusters and interfacial areas. Owing to the lower kinetic energy from sputtered atom–Ar ion collisions, elevated Ar pressure led to the formation of porous films with decreased grain size and increased film roughness, suggesting that sputtering pressure dominates the microstructure.118
Yao et al.119 tailored the nanostructure of magnetron-sputtered Ni–Nb metallic glass thin films by varying the substrate temperature from room temperature to 773 K. Upon increasing the substrate temperature above 573 K, a refinement of the columnar structure was observed, resulting in a smoothening of the thin film surface. Below 573 K, the columnar diameter was ∼40 nm, whereas it decreased to 20 nm at elevated temperature. Similarly, the roughness parameter Rq decreased from 1.5 nm below 573 K to 1 nm at higher temperatures. This investigation demonstrated a clear correlation between the nanostructure length and the density of the thin films. The density of the thin films was determined from x-ray reflectometry, and it was found to increase from 7.2 g/cm3 for substrate temperatures below 573 K to 8.0 g/cm3 for higher substrate temperatures. In addition to demonstrating the importance of controlling the diffusion at the substrate surface to adjust the structure and properties of metallic glass thin films, these results reveal a lower structural density within glass–glass interfaces.
Ghidelli et al.120 used pulsed laser deposition to control the structure of metallic glass thin films from dense amorphous to amorphous nanogranular over amorphous embedded nanocrystals by adjusting the background pressure during deposition. The deposition under a low vacuum resulted in a dense amorphous film, while a structural transition from composite amorphous–nanocrystalline to nanogranular amorphous was observed upon increasing the background helium pressure from 5 to 100 Pa. It was hypothesized that atom-by-atom growth was responsible for the formation of dense amorphous structures under low vacuum, while cluster assembly was thought to be responsible for the growth of films under higher pressures. By Advanced TEM analysis revealed a nano-laminated atomic structure. This structure was found to consist of alternating layers that each had a distinct chemical enrichment and local atomic order. By adjusting the film architecture, it was possible to obtain mechanical properties that included a high total elongation to fracture, giving a good strength/ductility balance, a high hardness, and an elastic modulus ranging from 10 to 140 GPa.120 This development of an entirely new category of engineered nanostructured metallic glass films with potential applications in the microelectronics and coating industries is especially significant.
Nanostructured metallic glass thin films have also been prepared by irradiating a partially crystalline Fe–Ni metallic glass composite thin film with swift heavy Au9+ ions.121 This investigation demonstrated that irradiation results in the fragmentation of fine nanocrystals (d ∼ 3 nm) embedded in an amorphous matrix. On the basis of this study, Thomas et al.121 proposed that strain transfer to the nanocrystallites brought about by loss of electronic energy was responsible for the fragmentation of the nanograins. Upon irradiation, the surface roughness of the films initially decreased for low fluence values and increased at higher fluence. The surface morphological changes were attributed to volume diffusion.
Chen et al.122 reported the formation of a chemically heterogeneous nanostructure in a Zr–Al–Cu–Ni metallic glass by Ar+ ion irradiation. After irradiation, they observed Cu- and Ni-enriched regions in both amorphous and crystalline structures, with sizes ranging from 30 to 50 nm. Ion irradiation led to the migration of Cu and Ni atoms within the irradiated metallic glass, which resulted in the formation of crystalline and amorphous structures under the influence of the radiation.122 These results highlight the interaction of monolithic glasses and heavy ions and the role of selective diffusion in the formation of glassy nanostructures.
C. Cluster ion beam deposition
Cluster beam deposition (CBD) is a novel nanoglass synthesis technique that generates and deposits clusters or nanoparticles onto a substrate to form a glassy thin layer. One CBD approach developed by Fischer et al.123 uses inert gas condensation to cool and condense atoms or molecules into nanoclusters in a gas phase. These clusters are accelerated and beamed at a substrate in a vacuum chamber. The clusters containing a few hundred atoms (50 to 1000 atoms) are deposited using a sputter source. The final structure and the properties of deposited nanoglass films depend on the impact energy used for deposition, which ranges between 50 and 500 eV/cluster. To demonstrate the capabilities of this method, a sequence of experiments were conducted, involving the embedding Fe clusters in Ag matrices with varying volume fractions of clusters.123
D. Severe plastic deformation
Generally, remarkably high cooling rates (105–106 K/s) are essential to produce metallic glasses and inhibit crystallization of the melt. As an alternative, severe plastic deformation (SPD) methods have been used to prepare bulk metallic glasses with enhanced free volume. This process involves two steps: initially, the materials are ball-milled using a high-energy plant ball mill, following which they are melt-quenched.110 Wang et al.124 investigated an Au-based bulk metallic glass after SPD. They observed that the SPD caused modification of the glass’s atomic structure by localized shear band formation, resembling the structure of a nanoglass.
E. Chemical methods
Several studies have revealed that electrochemical methods can be used to synthesize nanoglasses. Amorphous materials with inhomogeneities on the nanometer scale can be obtained by tuning parameters such as bath temperature, voltage, and pulse duration. In this method, reduction of dissolved metal salts using an aqueous borohydride solution leads to the formation of amorphous alloy nanoclusters.11 Kushima et al.125 performed real-time monitoring of a single ZnO nanowire as it underwent lithiation in a Li-ion battery configuration. They observed that the nanowire transformed into a nanoglass with multiple domains. This transformation occurred through a mechanism that involved the formation of nanocracks ahead of the lithiation front, followed by amorphization. This process is different from the behaviors observed in SnO2 nanowires, owing to the distinctive properties of Zn(II).125 Fe50B50 nanoglass powder has been synthesized by a chemical reduction method.126 Recently, with application to bone prostheses in mind, Druzian et al.127 synthesized nanoglass from agricultural residue consisting of rice husk using the sol–gel method. Rice husk has a high concentration of silica and has been used as a filler in metallic as well as ceramic matrix composites. This nanoglass incorporated magnesium nanoparticles, resulting in increased crystallinity, with an average crystal size of 1.35–2.11 nm and three times improved surface area. Zeta potential results revealed a negative surface charge, an indicator of enhanced biological cell adhesion. It should be noted that chemical synthesis of nanoglass might have advantages over other synthesis techniques, since it allows economical large-scale production.
IV. MULTIDIMENSIONAL ATTRIBUTES OF NANOGLASS MATERIALS
The complicated characteristics of nanoglass materials are examined in this section, which considers the following aspects: their intrinsic compositional changes, such as core–shell discrepancies; the effects of the electronic structures of nanoglasses on conductivity and other electrical properties; their thermal behavior, including their ability to withstand extreme temperature; their mechanical robustness and resilience under stress; and their enhanced magnetic properties, which are relevant to electronic and magnetic device applications.
A. Nanoglass structural dynamics
The fundamental structural difference between nanocrystalline materials and nanoglasses lies in the fact that nanoglasses have amorphous structures like glasses and lack an ordered atomic arrangement. As a result, there is no long-range order, in contrast to nanocrystalline materials, which have an ordered atomic arrangement. As a result, obtaining atomistic descriptions of such nanoglasses proves to be a challenging task. However, their structure can be statistically analyzed to describe key characteristics such as short-range order (SRO) and medium-range order (MRO). The radial distribution function (RDF) is the most widely used tool to describe the structure of amorphous materials. The RDF provides knowledge about the average bond length and the coordination number, as well as the possibility of finding specific atomic pairs as a function of the distance between the pair. Variations in the composition of a material or in the atomic positions of its constituents have a significant impact on its properties. NMR is a powerful tool to examine atomic disorder in the solid state, since it is very sensitive to the local atomic-scale environment and does not require the existence of long-range order.128 It provides information on high-order symmetry by measuring the local electric field gradient around specific quadrupole nuclei.
To study the structure of nanoglasses, the local phase separation length scale is introduced. TEM, positron annihilation spectroscopy (PAS), and XRD show a two-phase nanoglass model,129 with interface-connected nanometer-sized crystalline or amorphous building blocks. This produces nanocrystalline materials and nanoglasses. Nanocrystalline materials and nanoglasses have different atomic and electronic structures from single crystals or glasses with the same chemical compositions. The high density (∼1015 mm−3) of nanoscale ligaments causes the entire material to react and form a solid with varying mechanical, electric, magnetic, and other properties.129
In TEM images of Fe25Sc75116 and Au46Cu27Si14Al5Pd2130 nanoglass structures, two distinct dark and bright regions depict nanometer-sized regions of higher density linked by interfacial regions with the reduced density of a nanoglass. The glassy region forms the first phase, while the interfacial region forms the second phase. This can be seen from the structural model of nanoglass in Fig. 8. The second phase, which forms glassy region interfaces, is a new noncrystalline state. Small-angle x-ray scattering (SAXS) experiments on Sc75Fe25 nanoglasses reveal their structure. Glassy regions and their interconnecting interfaces with reduced density cause SAX curve humps.116 This method has been used to obtain atomic structural images of two-dimensional silica glass, as well as crystalline precipitates in glass.131 It enables short- and medium-range characterization of nanoglass structures on a local level.132
The thickness and area of glassy regions have been measured using advanced techniques. TEM has shown that the nanoglass interface volume segment is about 50%. The interface density may be reduced by about 12% relative to the glassy regions. Nanoglass structural heterogeneity has been studied using fluctuation electron microscopy (FEM). Diffraction patterns differ in the FEM graph, which may indicate medium-sized cluster orientation or medium-range order (MRO) in the probed volume. The scattering angle and volume dependence of the scattering variance can be used to determine the nanoglass MRO. However, the results of FEM cannot be directly interpreted in terms of the atomic packing. Initially, FEM was used to image the small clusters that resemble crystalline order in amorphous silicon and germanium, which are also known as paracrystalline materials.133 Local order in the seemingly homogeneous amorphous metallic glass structure has been confirmed from nano-beam diffraction maps using an electron beam diameter of 0.36 nm.134 Finding a solution to the challenge of determining the atomic configuration of metallic glasses has been a longstanding topic of discussion in materials science and solid state physics. It has important implications for comprehending the atomic mechanisms underlying the formation of metallic glasses as well as their properties. A significant result offers convincing verification of the existence of local atomic order in disordered materials.134
Positron annihilation lifetime spectroscopy (PALS) measures the positron lifetime, which is stabilized by low-electron-density defects or regions.135,136 This helps determine the void size (free volume) in glasses. Fang et al.116 examined the free volume allocation in as-prepared Sc75Fe25 nanoglass and an annealed sample. PALS measurement of the structure of Sc75Fe25 nanoglasses revealed that these comprise 65 vol. % glassy and 35 vol. % interfacial regions. Atomic-scale computer simulation has provided a significant detailed insight into the structure of nanoglasses. Molecular dynamics simulation (MDS) elucidates the unusual mechanical properties of metallic nanoglasses and the origin of excess volume at the glass–glass interfaces. MDS can be used to examine the topological structure, mechanical properties, and thermal strength of metallic nanoglasses, such as the Cu–Zr system, owing to the availability of reliable interatomic potentials.9,33 The MDS results provide evidence that interfaces in nanoglasses have a width of at least 2.0 nm.9 MDS has also recently revealed delocalization of glass–glass interfaces into a broader region of reduced density.115 Table IV summarizes the analytical methods used to study nanoglass and nanocrystalline structure, together with their respective advantages and disadvantages. Nanoglass researchers can use this table to choose the best methodological approach for their research goals and understand the pros and cons of each technique for characterizing complex amorphous and crystalline nanostructures.
Method . | Advantages . | Disadvantages . |
---|---|---|
Radial distribution function (RDF) | • Provides insights into local structure, with information on bond lengths and coordination numbers. | • Offers only statistical averages, possibly missing structural complexity. |
• Identifies specific atomic pair distances, useful for studying SRO. | • Limited insights into MRO and spatial arrangements beyond nearest neighbors. | |
Nuclear magnetic resonance (NMR) | • Highly sensitive to local atomic environments. | • Requires specialized equipment and expertise. |
• Probes high-order symmetries and local electric field gradients for detailed local structure analysis. | • Interpretation can be challenging in disordered systems. | |
Transmission electron microscopy (TEM) | • High-resolution imaging for atomic- or nanometer-scale visualization. | • Sample preparation can be complex and may introduce artifacts. |
• Can differentiate between crystalline and amorphous phases. | • Limited field of view and depth of focus. | |
Fluctuation electron microscopy (FEM) | • Sensitive to MRO, capturing structural heterogeneity. | • Results not straightforward to interpret in terms of atomic packing. |
• Identifies medium-sized cluster orientations or arrangements. | • Requires advanced electron microscopy facilities. | |
Positron annihilation lifetime spectroscopy (PALS) | • Measures void size or free volume, crucial for understanding mechanical behavior. | • Complex interpretation requiring calibration or known standards. |
• Sensitive to defects and low-electron-density regions. | • Does not provide direct atomic arrangement information. | |
Molecular dynamic simulation (MDS) | • Detailed atomic-scale insights into structure and properties. | • Depends on accuracy of interatomic potentials. |
• Simulates various conditions for predictive analysis. | • High computational intensity requiring significant resources. |
Method . | Advantages . | Disadvantages . |
---|---|---|
Radial distribution function (RDF) | • Provides insights into local structure, with information on bond lengths and coordination numbers. | • Offers only statistical averages, possibly missing structural complexity. |
• Identifies specific atomic pair distances, useful for studying SRO. | • Limited insights into MRO and spatial arrangements beyond nearest neighbors. | |
Nuclear magnetic resonance (NMR) | • Highly sensitive to local atomic environments. | • Requires specialized equipment and expertise. |
• Probes high-order symmetries and local electric field gradients for detailed local structure analysis. | • Interpretation can be challenging in disordered systems. | |
Transmission electron microscopy (TEM) | • High-resolution imaging for atomic- or nanometer-scale visualization. | • Sample preparation can be complex and may introduce artifacts. |
• Can differentiate between crystalline and amorphous phases. | • Limited field of view and depth of focus. | |
Fluctuation electron microscopy (FEM) | • Sensitive to MRO, capturing structural heterogeneity. | • Results not straightforward to interpret in terms of atomic packing. |
• Identifies medium-sized cluster orientations or arrangements. | • Requires advanced electron microscopy facilities. | |
Positron annihilation lifetime spectroscopy (PALS) | • Measures void size or free volume, crucial for understanding mechanical behavior. | • Complex interpretation requiring calibration or known standards. |
• Sensitive to defects and low-electron-density regions. | • Does not provide direct atomic arrangement information. | |
Molecular dynamic simulation (MDS) | • Detailed atomic-scale insights into structure and properties. | • Depends on accuracy of interatomic potentials. |
• Simulates various conditions for predictive analysis. | • High computational intensity requiring significant resources. |
B. Electronic structures of nanoglasses
The distinct atomic arrangements observed in the glass–glass interface and the adjacent glassy regions could be attributed to the unique electronic structures in both regions. This was first confirmed from the deviation in the Mössbauer isomer shift (IS) of the interfacial component of Pd70Fe3Si27 glasses and the corresponding value of melt-cooled glass with a comparable chemical composition.34 Figure 5 shows the QS in the Mössbauer spectrum of Pd70Fe3Si27 nanoglass, which comprises two components. While the first component coincides with the peak of the corresponding melt-spun glass, the second (the red curve at about 0.9 mm/s) is only visible in the nanoglass. This provides a firm confirmation of the different atomic structures in the glass–glass interface of nanoglasses. Similar results have been reported for an Fe90Sc10 glass.137 The atomic and electronic structures of the interfacial region vary from those of the glassy regions of a chemically identical quenched melt at the glass transition temperature Tg. This shift can be explained by the widening of the interfacial region due to atomic relaxation.
C. Ultra thermal stability
Annealing of a nanoglass creates a wider region with increased free volume and delocalizes its interfaces.138 This free volume will delocalize uniformly across the glass volume if it is annealed longer. The average glass density will be lower than the density at the nanoglass interfaces. Because the short-range order in an annealed nanoglass differs from the initial configuration, delocalization creates a new atomic structure. Such delocalization should only occur when the initial configuration’s free energy is higher than the later delocalized configuration.139 The free surfaces of small glassy clusters provide more degrees of freedom for atomic rearrangements, allowing atoms to relax into configurations with higher density and lower free energy.129 Dziuba et al.140 have revealed a connection between high stability and low potential energy. They used a vapor deposition technique to fabricate an ultra-stable amorphous phase of Cu50Zr50 on SiO2 substrates. The high substrate temperature (320 °C) and low deposition rate (0.08 nm/s) enhanced the stability and homogeneity of the amorphous sample. It was thus demonstrated that ultra-stability is a tunable property. The enhanced thermal stability and MRO of nanoglass are consequences of atomic relaxation.
Figures 9(i-a) and 9(i-b) shows the DSC curves of an Au52Ag5Pd2Cu25Si10Al 6 nanoglass and a glassy ribbon with the same chemical composition. The glass transition temperature Tg of the nanoglass is only slightly higher than that of the corresponding melt-cooled ribbon, but its crystallization temperature Tx is 25 K higher.141 A similar result was obtained for an IGC-produced Cu50Zr50 nanoglass compared with a rapidly quenched ribbon [Fig. 9(ii)].115 The Tg of the nanoglass is 8.0 K higher than that of the ribbon, and its crystallization peak is smaller and broader.
D. Mechanical behavior
Nanoglasses demonstrate excellent mechanical properties, such as improved plasticity, hardness, and elastic modulus compared with their corresponding melt-quenched ribbons. In comparison with monolithic metallic glasses, nanoglasses have superior plastic deformation capabilities, and their increased plasticity can be attributed to their distinctive microstructure.142
The deformation behavior of a Sc75Fe25 nanoglass was investigated by microcompression testing and compared with that of the corresponding melt-quenched metallic glass.2,142 The Sc75Fe25 nanoglass plastically deformed at a stress of about 1250 MPa and exhibited a plastic strain of up to about 15%. The fracture stress was found to be about 1950 MPa, while the corresponding glassy ribbon showed a brittle nature, exhibiting a plastic deformation of less than 1% at fracture. Micropillar compression and in situ tensile tests revealed the more ductile nature of the nanoglass. The tensile stress–strain curves of IGC-produced Sc75Fe25 nanoglass and rapid-quenched glass shown in Fig. 10(i-a) illustrate the ductile deformation pattern, confirming the significant plasticity of the nanoglass beyond the yield point. Notably, being ductile-dominated materials, these nanoglasses exhibit a higher hardness and elastic modulus than their rapid-quenched counterparts, with 10%–20% higher moduli.115,141,142 Nanoindentation testing has demonstrated the homogeneous deformation behavior of nanoglasses.
Owing to their nanoscale structure with a high density of glass–glass interfaces, nanoglasses are more ductile than melt-quenched glasses. Interfaces between nanometer-sized amorphous clusters result in structural variability and free volume at the frontiers. This structural arrangement improves stress absorption and distribution under deformation, reducing the crack initiation and propagation that cause brittleness in traditional glasses. These surfaces also enable local shear band development and sliding mechanisms, which enable plastic deformation. The increased free volume at glass–glass interfaces increases atom or atomic cluster mobility, making the material tougher by providing more energy dissipation pathways during deformation. Thus, nanoglasses’ interconnected amorphous areas with high interface density contribute to the better ductility and toughness of nanoglasses compared with melt-quenched glasses.141–143
Figure 10(i) shows stress–strain curves from tension tests of Sc75Fe25 nanoglass and rapid-quenched glass, together with SEM images. Ghidelli et al.120 showed that the hardness of metallic glass thin films deposited by pulsed laser deposition decreased upon the transition from dense glass to nanogranular glasses. At the same transition, they also observed the emergence of tensile ductility. Furthermore, metallic glasses have been considered for tribological applications in different environments. When comparing the nanometer-scale deformation of an oxide-free metallic glass surface with a pure metal surface in an ultrahigh vacuum, Caron and Bennewitz144 demonstrated the localized and homogeneous flow of the metallic glass by AFM indentation. Their results are in strong contrast to the deformation of a single-crystalline surface characterized by atomic-scale pop-ins.
The nanoindentation behavior of Cu50Zr50, Fe25Sc75, and Fe90Sc10, and nanoglasses produced by IGC was compared with their corresponding melt quenched ribbons with identical chemical composition.115,142 As expected, the load vs displacement curves differed [Fig. 10(i-a)]. The nanoindentation curve of the rapid-quenched ribbons exhibited sharp displacement bursts, attributed to shear localization and heterogeneous deformation by shear banding, while no such pop-in events were visible in case of the nanoglasses. SEM images of the indents also clearly displayed a shear band on the rapid-quenched ribbons, in contrast to the nanoglasses [Fig. 10(i-b)]. To take advantage of the structural benefits of nanoglasses, Katnagallu et al.7 fabricated a bulk nanoglass–nanocrystal composite comprising grains of an Fe90Sc10 amorphous matrix [Fig. 10(i-a)]. They examined it at the true atomic level and revealed a complex intrinsic structure and chemistry. The distribution of nanoglass and nanocrystal phases contributed to high mechanical strength and high plasticity. The true stress–strain curve exhibited one of the highest yield strengths of 2.5 GPa among Fe-based alloys, as can be seen in Fig. 10(ii-b). This surpassed all the strengths reported for steels, and was even twice as high as that found previously for an Sc75Fe25 nanoglass.
Under ambient conditions, nanotribological investigations have shown how friction and wear of metallic glasses are affected by their surface oxides. Although abrasive wear is the leading degradation mechanism for metallic glasses, the presence of a thin native or grown surface oxide significantly extends the domain of shearing friction, thus retarding and reducing abrasive wear.145,146 Compared to their rapidly melt-quenched counterparts, Ni60Nb40 metallic nanostructured thin films exhibit earlier onset of abrasive wear, while the friction coefficients of both nanostructured and monolithic glasses are similar.118,146 These results give hints as to the determining role of glass–glass interfaces in controlling the plastic flow of nanoglasses. Thus, two scenarios may be envisaged: the presence of interfaces could delocalize shear transformations, or the flow of nanostructured glasses could be mediated by glass–glass interfacial sliding. Hence, nanoglasses have the potential for multifunctional applications in areas with strict demands regarding structural properties. Thus, the two-phase model of nanoglasses opens an unprecedented door to a deeper knowledge of the structure of these materials.
E. Magnetic properties
Studies have revealed that Fe90Sc10 nanoglass is a robust ferromagnet, while its melt-quenched glassy counterpart is paramagnetic. The magnetic properties of this nanoglass have been investigated using Mössbauer spectroscopy and magnetic Compton scattering.147 Ferromagnetism in Fe90Sc10 nanoglass at ambient temperature is only observed when the nanospheres are compressed. Thus, it can be concluded that the regions between the spheres are magnetically arranged, with structural and electronic changes compared any other known alloys.1 The ferromagnetism of nanoglass could be attributable to its low-atomic-density glass-glass interfaces. Ghafari et al.147 attributed the ferromagnetic state of Fe90Sc10 nanoglass to itinerant sp electrons and 3d electrons. The itinerant sp electrons present in the interfacial region perform a crucial role in the magnetic behavior of the nanoglass. The average magnetization in Fe90Sc10 nanoglass is 1.05 μB per Fe atom.137 Gleiter1 presented Mössbauer spectra recorded at 295 K for melt-spun ribbon, nanosphere powder prior to consolidation, and nanoglass. The single line spectra of the ribbon and the isolated nanometer-sized glassy spheres suggested that both are paramagnetic. However, the corresponding spectrum of the consolidated nanoglass was significantly different, consisting of two components, resembling those of paramagnetic and ferromagnetic materials, respectively. Figure 11 displays the magnetization vs external magnetic field plots for Fe90Sc10 nanoglass and melt-quenched regular glass at 300 K. The nanoglass is ferromagnetic, while the melt-quenched regular glass is paramagnetic.1,110
V. BIOFUNCTIONAL NANOGLASS
There is currently no reliable and reproducible method available for profitable production of nanoglasses, even though these are obvious technologically attractive materials. With regard to the toxicological aspects of nanoglasses, there is a need for rigorous evaluation of their interaction with biological systems and the environment, with consideration of possible surface modification, use of biocompatible coatings, and implementation of green synthesis methods. The advantages that nanoglasses offer in the field of biomedical applications are specifically attributable to the fact that they are both strong and biocompatible. Enhanced methods for synthesis, modification, and characterization can result in improved structures and a broader range of applicability, both of which are necessary for bioactivity. The significance of nanoglasses in the biological field could be increased further by enriching their functional and technological aspects.112,113,147
A. Bioactive nanoglass materials
Nanoglass materials are currently seeing an increase in their range of applications, owing to their distinctive structures and properties. A list of some of these applications in the medical, chemical, and physical fields is presented in Table V. In particular, the biological, chemical, and physical properties of nanoglasses have led to their widespread adoption in the healthcare industry. A recent study has demonstrated the bioactivity and antibacterial properties of gel-derived SiO2–CaO–P2O5–SrO–Ag2O–ZnO glass.149 Ni60Nb40 nanoglass has been shown to have useful nonenzymatic glucose sensing properties.150 Medical devices for use inside the human body require specific properties for human compatibility, and nanoglasses are among the best options for this application.151 The role of nanoglasses in enhancing ion conduction and luminescence is well established.152,153 A silica glass/reduced graphene oxide nanoglass material has been synthesized for advanced electrochemical applications.154 The physical characteristics of nanoglasses enable them to contribute effectively in the space, engineering, and medical devices industry with research on Tb75Fe25, aluminum nitride and Fe2O3.SiO2 nanoglasses, respectively.155–157
Category . | Application . | Type of nanoglass . | References . |
---|---|---|---|
Medical | Antibacterial properties | Gel-derived SiO2–CaO–P2O5–SrO–Ag2O–ZnO | 149 |
Nonenzymatic glucose sensing | Ni60Nb40 nanoglass | 150 | |
Expandable stents | Nanoglass-based balloon | 151 | |
Chemical | Fast ion conduction | Lithium silicate glasses | 152 |
Enhanced luminescence | Ga2O3:Ni nanoglass | 153 | |
Advanced electrochemical | Silica glass/reduced graphene oxide | 154 | |
Physical | Cryogenic | Tb75Fe25 nanoglass | 155 |
Super-ductility | Nanoglass aluminum nitride | 156 | |
Magnetodielectric effect | Fe2O3.SiO2 nanoglass | 157 |
Category . | Application . | Type of nanoglass . | References . |
---|---|---|---|
Medical | Antibacterial properties | Gel-derived SiO2–CaO–P2O5–SrO–Ag2O–ZnO | 149 |
Nonenzymatic glucose sensing | Ni60Nb40 nanoglass | 150 | |
Expandable stents | Nanoglass-based balloon | 151 | |
Chemical | Fast ion conduction | Lithium silicate glasses | 152 |
Enhanced luminescence | Ga2O3:Ni nanoglass | 153 | |
Advanced electrochemical | Silica glass/reduced graphene oxide | 154 | |
Physical | Cryogenic | Tb75Fe25 nanoglass | 155 |
Super-ductility | Nanoglass aluminum nitride | 156 | |
Magnetodielectric effect | Fe2O3.SiO2 nanoglass | 157 |
B. Biological interaction of materials
Nanoglasses show great promise for the preparation of biologically interactive materials to restore physiological functions of the human body. The development of next-generation bionanoglasses through the incorporation of specific materials and targeted drugs will bring a new range of applications. Such developments may be significant for antibacterial and antiviral treatments and for tissue regeneration.148,149
The biocompatibility of materials and the cellular response to them depend on their microstructure, surface structure, and chemical composition. The structure of novel nanoglasses provides the option to tailor their microstructure and surface structure to make them suitable for use as implants. Nanoglasses consisting of various nanoparticles of different alloys have been prepared through the IGC process.2,9 This allows the creation of new materials with desired properties by adjusting the volume fraction of the alloy particles, paving the way toward the fabrication of new noncrystalline materials with improved biocompatibility. To study the influence of nanoscale microstructure on bioactivity, a hierarchically structured layer metallic nanoglass of Ti34Zr14Cu22Pd30, was designed by magnetron sputtering on various substrates.118
A recent study79 explored cell growth on nanomaterial surfaces, specifically comparing Ti34Zr14Cu22Pd30 nanoglass with pure titanium surfaces. Cell growth rates on both materials were comparable on the first day. However, by the seventh day, the nanoglass surface exhibited significantly higher cell proliferation than the pure titanium surface, with the cell density on the nanoglass being ∼15 times greater than that on the titanium surface. This finding underscores the potential of nanoglasses like Ti34Zr14Cu22Pd30 in biomedical applications, especially given the ongoing search for stronger biomaterials. Traditional biomaterials often fall short in load-bearing capacities, a gap that nanoglasses could potentially fill, making them attractive options for tissue engineering and the replacement of metal-based implants in healthcare.118
C. Advent of nanoscale biomedicals
Nanoglass pastes provide a specific biomaterial platform that may release multiple ions (silicate, calcium, and copper) and thus have potential uses in regenerative therapy to secure surrounding cells and tissues and create an environment free of bacteria. It is possible to create a nanoglass paste that has multiple therapeutic applications based on its antibacterial, pro-angiogenic, and osteo-promotive properties. Table VI outlines the various functions that can be performed by bioglasses. These functions include the creation of novel properties, the modification of structural characteristics, and the fulfillment of various functional requirements.
Type of bioglass . | Bioactivity and compatibility . | References . |
---|---|---|
Scaffolds of porous bioglass/chitosan | Drug delivery system for bone regeneration | 158 |
Scaffolds of PCL combined with bioglass | Biological performance | 159 |
Bioactive glass–polycitrate hybrid | Osteogenesis ability | 160 |
Printed bioglass/gelatin/alginate composite scaffolds | Strength, biomineralization, cell responses, osteogenesis | 161 |
Scaffold of nanobioglass/silk fibroin/carboxymethyl cellulose | Bone tissue engineering | 162 |
Bioglass/gliadin/polycaprolactone ternary composite | Strength, degradability, cell responses, bone regeneration | 163 |
Gadolinium-doped bioglass scaffolds | Promote osteogenic differentiation | 164 |
Zinc-doped bioglass | Nasal tissue treatment | 165 |
Cerium oxide in mesoporous bioglass | Activation of ERK signaling pathway | 166 |
Nanogel/boron-containing bioactive glass composite scaffold | Bone regeneration | 167 |
Sol–gel-based synthesis and nano bioglass | Bone tissue regeneration | 168 |
Sol–gel based bioactive glasses | Osteogenic potential | 169 |
Gel-derived SiO2–CaO–P2O5–SrO–Ag2O–ZnO bioactive glass | Bioactivity, biocompatibility, antibacterial properties | 170 |
Implants of nanobioglass/polyetheretherketone composite | Improved antibacterial activity through release of hinokitiol | 171 |
Bioglass-sustained scaffold with ECM-like structure | Enhanced diabetic wound healing | 172 |
Bioglass-based antibiotic-releasing bone-void filling putty | Treatment of osteomyelitis, aiding bone healing | 173 |
Type of bioglass . | Bioactivity and compatibility . | References . |
---|---|---|
Scaffolds of porous bioglass/chitosan | Drug delivery system for bone regeneration | 158 |
Scaffolds of PCL combined with bioglass | Biological performance | 159 |
Bioactive glass–polycitrate hybrid | Osteogenesis ability | 160 |
Printed bioglass/gelatin/alginate composite scaffolds | Strength, biomineralization, cell responses, osteogenesis | 161 |
Scaffold of nanobioglass/silk fibroin/carboxymethyl cellulose | Bone tissue engineering | 162 |
Bioglass/gliadin/polycaprolactone ternary composite | Strength, degradability, cell responses, bone regeneration | 163 |
Gadolinium-doped bioglass scaffolds | Promote osteogenic differentiation | 164 |
Zinc-doped bioglass | Nasal tissue treatment | 165 |
Cerium oxide in mesoporous bioglass | Activation of ERK signaling pathway | 166 |
Nanogel/boron-containing bioactive glass composite scaffold | Bone regeneration | 167 |
Sol–gel-based synthesis and nano bioglass | Bone tissue regeneration | 168 |
Sol–gel based bioactive glasses | Osteogenic potential | 169 |
Gel-derived SiO2–CaO–P2O5–SrO–Ag2O–ZnO bioactive glass | Bioactivity, biocompatibility, antibacterial properties | 170 |
Implants of nanobioglass/polyetheretherketone composite | Improved antibacterial activity through release of hinokitiol | 171 |
Bioglass-sustained scaffold with ECM-like structure | Enhanced diabetic wound healing | 172 |
Bioglass-based antibiotic-releasing bone-void filling putty | Treatment of osteomyelitis, aiding bone healing | 173 |
Structural modification to produce composite scaffolds provides several unique properties in bioglasses. Scaffolds of bioglass with chitosan, polycaprolactone (PCL), and polycitrate posses useful biological performances, such as bone regeneration.158–160 Bioglass scaffolds that provide the strength-engineering functionality of bone tissue have been studied with gelatin, silk fibroin, and polyetheretherketone compounds.161–163 Importantly, doped bioglass provides varied functionality, depending upon the elements used in the scaffold. Gadolinium, zinc, and cerium oxide in mesoporous bioglass scaffolds promote osteogenic differentiation, treatment of nasal tissues, and the ERK signaling pathway respectively.164–166 Structural compatibility is important for tissue regeneration, and therefore sol–gel-based synthesis is applicable for the preparation of material for bone tissue regeneration.167–169 Potential mismatch of mechanical and elastic properties between implant and natural bone is the primary cause of concern in the field of bone tissue regeneration using metallic implants. Such a mismatch can result in stress shielding, which leads to loosening of the implant. A recent study has been reported in which nanobioglasses with titanium and a varying proportion of fluoride were fabricated using melt-quenching methods to avoid those drawbacks.170 The elastic strength of the fluoride-doped phosphate-based titanium nanobioglasses was comparable to that of normal human bone and better than previously reported metal-doped bioglasses. The rate of biodegradation was closer to the rate of bone growth, with an improved bioactivity of 62% in a brief period of 10 weeks.
Specific modifications to the structural properties of bioglasses provide antibacterial and wound healing properties important for infection-free medical procedures.149,171–173 Biocompatibility provides multiple therapeutic and health promotive opportunities, and as a result, research into nanoglasses and the adoption of advanced materials technology will contribute effectively to the fields of medicine and healthcare.
D. Elucidation of physicochemical activity
Nanoglasses exhibit differences in behavior between their interiors and surfaces, with the interiors possessing stable, amorphous structures while the surfaces exhibits increased reactivity and altered properties due to the high surface-to-volume ratio and the presence of interfacial regions.8 A deeper understanding of the physicochemical properties of nanoglasses will open up a previously unexplored avenue for translational research, paving the way for the application of these materials in a wide variety of fields, including materials engineering, biotechnology, and medical science. Table VII presents various types of nanoglass, along with their respective functionalities and related studies.
Study . | Type of nanoglass . | Functionality . | References . |
---|---|---|---|
Scaffold development | Nanoglass | Tissue engineering | 174 |
Glucose sensing | Ni60Nb40 | Sensor devices | 175 |
Expandable stents | Nanoglass-based balloon | Biomedical | 176 |
Bacterial infection | Paste | Regenerative process | 177 |
Oxide glass systems | Chalcogenide glasses | Nanocrystallinity | 178 |
Multilayered structure | Nanodimensional silica | Electrochemical devices | 179 |
Ultra-large-scale integration | Nanoglass® E porous ultra-low-k material | Metal integration in semiconductor devices | 180 |
Molecular dynamics | Cu–Zr | Ultrahigh strength and tensile plasticity | 181 |
Concrete performance | Powder and fly ash | Structural engineering | 182 |
Removal of lead ion | Nanoparticles | Pollution control | 183 |
Cathodic activation | Fe-based nanoglass | Oxygen for water splitting | 184 |
Study . | Type of nanoglass . | Functionality . | References . |
---|---|---|---|
Scaffold development | Nanoglass | Tissue engineering | 174 |
Glucose sensing | Ni60Nb40 | Sensor devices | 175 |
Expandable stents | Nanoglass-based balloon | Biomedical | 176 |
Bacterial infection | Paste | Regenerative process | 177 |
Oxide glass systems | Chalcogenide glasses | Nanocrystallinity | 178 |
Multilayered structure | Nanodimensional silica | Electrochemical devices | 179 |
Ultra-large-scale integration | Nanoglass® E porous ultra-low-k material | Metal integration in semiconductor devices | 180 |
Molecular dynamics | Cu–Zr | Ultrahigh strength and tensile plasticity | 181 |
Concrete performance | Powder and fly ash | Structural engineering | 182 |
Removal of lead ion | Nanoparticles | Pollution control | 183 |
Cathodic activation | Fe-based nanoglass | Oxygen for water splitting | 184 |
Owing to their unique properties, the applications of nanoglasses are constrained by some characteristics, including fracture, density, and strength. To overcome such limitations, nanoglasses that feature appropriate combinations of materials and novel modifications of their structural makeup are required.
Specific types of nanoglasses have been found to be suitable for tissue engineering,174 sensor devices,175 as expandable stents,176 and to aid tissue regeneration.177 The electronic and electrochemical properties of silica and ceramic nanoglass can be exploited in device development.178,179 A porous ultra-low-k material has been developed to facilitate large-scale integration.180 A Cu–Zr nanoglass has been shown to exhibit ultrahigh strength and tensile plasticity,181 while a nanoglass powder with fly ash promises to provide improved concrete performance.182 Pollution control through removal of lead ions by modified glass nanoparticles183 and the use of Fe-based nanoglass as a catalyst for oxygen evolution184 are important applications in the context of environmental sustainability.
Understanding the physicochemical characteristics of nanoglasses in combination with different materials will help efforts to improve their the durability, ductility, and strength. Furthermore, a comprehensive evaluation of the biofunctionality of these materials will be an essential aspect of future studies.
VI. APPLICATIONS, CHALLENGES, AND FUTURE PROSPECTS
Nanoglasses are key materials in photonics, physics, chemistry, materials engineering, and biology, as illustrated in Fig. 12. Nanoglasses are highlighted in photonics for their usage in improved optical devices, in physics for their integration into electronic systems, and in chemistry for their unique chemical makeup. Materials engineering uses nanoglasses to generate better materials, whereas biomedicine uses them in medical devices and tissue engineering. As shown in Fig. 12, nanoglasses play important roles in optoelectronics, in energy conversion and storage, and as advanced coatings and protective layers.
Nanoglasses have many desirable properties, including biological compatibility, chemical resistance, mechanical stability (e.g., elasticity), and light weight. These qualities make nanoglass materials suitable for use in a wide variety of applications. Specifically, they can be used in a variety of roles in health care and environmental protection, either alone or in combination with other materials.
However, their use comes with several potential drawbacks. The manufacturing process is complex and costly, requiring advanced equipment and techniques. There are also concerns about the long-term durability and stability of nanoglasses under various environmental conditions. Additionally, the production and disposal of nanoglass involve nanomaterials that could pose environmental and health risks, including nanoparticle release. Ensuring safe handling during manufacturing is crucial to mitigate these risks. Moreover, integrating nanoglasses into existing systems may present compatibility challenges. These factors must be carefully considered to fully assess the viability of nanoglasses in various applications.
A. Biological assessment, wound healing, and emerging applications
Bionanoglasses with their biocompatible properties have the potential to reconstruct damaged parts of the human body. These materials have also demonstrated antibacterial and antiviral properties. These reconstructive applications can be accomplished through the fabrication of bionanoglasses in various forms (such as coatings and bulk) to provide distinct functions in tissue repair and replacement.
It has been found that bioactive glasses and glass ceramics, as well as apatite–wollastonite (A-W) glass–ceramics, can exhibit a diverse array of biological behaviors, which are determined by the precise proportions of CaO, SiO2, Na2O, and P2O5 present in the material.185 The antimicrobial activity of nanomaterials is particularly effective against certain species of bacteria, which is something that needs to be further investigated. The increased pH of nanoglasses is responsible for their antibacterial activity.186 Chen et al.187 found that a Ti-based nanoglass composite exhibited substantially enhanced biocompatibility, including superior bioactivity such as enhanced cell proliferation and osteogenic phenotype.
The architectures and constituents of new materials have been modified to create microphysiological systems that mimic human tissue function and deliver bioactivity.188,189 Nanomaterial-based biosensors have been developed with controlled and programmable bioelectronics for applications to healthcare.190–192 Large-area skin damage can cause imbalanced skin homeostasis, inflammation, fluid loss, and bacterial infection. Bioactive glass nanopowder (BGN@PTE) is a multilayer dressing for sequential wound management, created by coating polytannic acid and ε-polylysine onto a bionanoglass for easy layer-by-layer assembly. BGN@PTE has been shown to provide significantly better wound repair than the Dermlin bioglass dressing.193
Figure 13 illustrates the synthesis and therapeutic application of a bioactive nanoglass hydrogel. This FABA hydrogel is easily made by self-crosslinking F127–CHO (FA) and alendronate sodium (AL)-decorated Si–Ca–Cu nanoglass (BA).194 The physicochemical activity of FABA hydrogel can reduce tumor necrosis factor α (TNF-α) expression and increase interleukin-4 (IL-4)/IL-10 expression. Such a nanoglass paste with ∼200 nm silicate-glass particles can release silicate, calcium, and copper ions at therapeutically relevant doses and sustainably (days to weeks), suggesting a potential role as a therapeutic-ion reservoir in surrounding cells and tissues. Nanoglass paste has beneficial properties, promoting endothelial cell angiogenesis in vitro and vasculature formation in vivo, and increasing the release of reactive oxygen species (ROS).
B. Sustainability evaluation and environmental aspects
The compatibility of nanoglass materials with environmentally friendly systems is not a given in every situation. When determining the environmental sustainability of a product, we focus on three main themes: (i) products that offer an eco-friendly aspect, while maintaining high quality standards; (ii) materials with the potential to drive functional enhancements or improve cost-effectiveness; and (iii) harmless products with proven technology. This new generation of materials and these new ways of thinking about them foster an environment that is conducive to accumulating valuable experience of these materials. We have high hopes that the medical device industry will acquire a better sense of design with new functionality on the basis of research reports on the materials considered in the design cases.192 Furthermore, the fabrication of materials from living organisms such as fungi and bacteria is an example of sustainable design and, as a result, compatible with nanoglass applications.195,196 Understanding the environmentally friendly and green chemistry that describes nanoglass in terms of the type and density of assemblies available at its surfaces is at major step in gaining an appreciation of its sustainable qualities.
C. Catalytic applications
Nanocatalysts could be crucial in various aspects of daily life because of the enhanced catalytic properties observed when a system is reduced to a nanoscale. Nanoscience explores functional approaches to wide-ranging applications of nanocatalysts such as water purification, fuel cells, energy storage, solid rocket propellants, biodiesel production, medicine, dyes, and carbon nanotubes.197 For example, Al73Mn7Ru20 has been produced by magnetron co-sputtering as ∼2 nm of medium-entropy nanocrystals with an amorphous phase of ∼2 nm, to be applied as a cost-effective electrocatalyst for large-scale H2 production, where its dual-phase structure enhances H2 evolution.198 Another example is a composite material containing palladium on a silica base, synthesized using an extractive–pyrolytic method, for hydrogen absorption–desorption, where dynamic sorption reveals that this composite sample based on Pyrex glass quickly attains a high concentration of hydrogen in the material. Conversely, a silica gel-based composite material rapidly achieves half of the hydrogen load, but thereafter the rate of hydrogenation increases gradually. The Pyrex glass-based material absorbs ∼5.6 times more hydrogen overall compared to the silica gel-based material. Finally, high-entropy alloy (HEA) catalysts have demonstrated remarkable catalytic abilities, particularly in complex carbon (C) and nitrogen (N) cycle reactions that involve multiple steps and various intermediates.199
D. Robustness and high resistance
In the aerospace and defense sectors, nanoglasses’ robustness and resistance to impact can enable the production of more durable and dependable components for aircraft, spacecraft, and military devices. The exceptional transparency of such materials could prove advantageous in the fabrication of premium optical lenses for cameras, telescopes, microscopes, and other imaging systems. This would guarantee precise light transmission with minimal distortion, ultimately leading to the production of more vivid and detailed images. Certain nanoglasses may offer surfaces that facilitate accurate touch input for touch-sensitive devices, while their scratch resistance ensures the durability of touchscreens. Nanoglasses have the potential to serve as oleophobic and hydrophobic coatings through the incorporation of photocatalytic materials that decompose organic contaminants upon exposure to light, thereby enhancing their self-cleaning capability.200,201 The pursuit of climate neutrality in healthcare and the environment is predicated on materials research prioritizing emerging materials.202–204 Finally, for the sake of global sustainability, it is essential to have an understanding of emerging materials and how they can be utilized.204–206
VII. CONCLUSION
This review has thoroughly covered the broad field of nanoglass research, including contemporary trends, alignment with Sustainable Development Goals, advanced synthetic methods, and the multifunctional properties of nanoglasses. Nanoglasses have emerged as highly adaptable components in the field of materials science, possessing dynamic structures that may be analyzed using modern methods such as Mössbauer spectroscopy. They exhibit remarkable thermal stability, mechanical durability, and magnetic characteristics. The exploration of biofunctional nanoglasses has initiated a fresh phase in the field of biomedicine, demonstrating the capabilities of bioactive materials in biological interactions and nanoscale medical applications. The investigation of potential uses has additionally uncovered the great potential of nanoglasses for wound healing, environmental sustainability, and catalysis, all the while preserving durability. The overall prospects for nanoglasses are highly promising, with the likelihood of several undiscovered significant breakthroughs in biomedical technology and quality of life. It is clear that nanoglasses will have a substantial impact in creating a sustainable and resilient future, representing a combination of human creativity with the limitless potential of nanotechnology.
ACKNOWLEDGMENTS
Anshuman Mishra acknowledges the International Association of Advanced Materials for receiving the Professor Herbert Gleiter Fellowship. M.A.F. acknowledges the financing support by Universidad Nacional del Sur (Grant No. PGI 24/Q112) and Grant No. PICT 2021-I-A-00288, Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT), Grant No. PIP 2021-2023 GI 11220200100317CO. Disclosure: The authors have utilized ChatGPT to enhance readability, graphics and language. Following this application, the authors meticulously reviewed and edited the content as necessary, assuming full responsibility for the publication of contents and adopted figures.
AUTHOR DECLARATIONS
Conflict of Interest
The authors have no conflicts to disclose.
Author Contributions
A.M., M.A.F., and A.C. contributed equally to this work.
Anshuman Mishra, Marisa A. Frechero, Arnaud Caron: Conception of the work, data collection and analysis, drafting the article, visualization, Pravin Kumar Singh: writing- review & editing, Ashutosh Tiwari: Conceptualization of the work, writing- review & editing.
DATA AVAILABILITY
Data sharing is not applicable to this article as no new data were created or analyzed in this study.