Reversible alteration of 3D printed polymer properties via infiltration of alumina by atomic layer deposition

3D printed acrylonitrile butadiene styrene (ABS) and polyvinyl alcohol (PVA) structures were infiltrated by alumina (Al₂O₃) using a trimethylaluminum(III) and water ALD process at 130 and 80 °C, respectively, to alter their physical properties. Differential scanning calorimetry was used to determine the glass transition temperature (T_g) of the polymers' pre- and post-deposition after varying the number of ALD cycles, resulting in a change of ∼9 and ∼ 27 °C for ABS and PVA, respectively. After one heat cycle, the postdeposition T_g reverted back to its predisposition point indicating reversibility of the deposition effects are possible. Optimal growing patterns, polymer composition, and inhibiting surface coatings—seen by energy-dispersive x-ray spectroscopy mapping—affected the amount of infiltration possible within the polymer substrate and, in turn, T_g. The results achieved provide guidelines to altering the physical and thermal properties of 3D printed polymer architectures.