We demonstrate that a mercaptan-terminated organophosphonate nanolayer at gold-titania interfaces can give rise to two- to three-fold enhancement in the interfacial fracture toughness and thermal conductance. Electron spectroscopy reveals that interfacial delamination occurs at the metal-molecule interface near the gold-sulfur bonds, consistent with density functional theory calculations of bond energies. Qualitative correlation between interfacial fracture toughness and bond energies suggest that organophosphonate nanolayers are resilient to humidity-induced degradation. These results, and the versatility of organophosphonates as surface functionalization agents for technologically relevant materials, unlock uncharted avenues for molecular engineering of interfaces in materials and devices for a variety of applications.
Gold-titania interface toughening and thermal conductance enhancement using an organophosphonate nanolayer
Philippe K. Chow, Y. Cardona Quintero, Peter O'Brien, P. Hubert Mutin, Michael Lane, R. Ramprasad, Ganpati Ramanath; Gold-titania interface toughening and thermal conductance enhancement using an organophosphonate nanolayer. Appl. Phys. Lett. 20 May 2013; 102 (20): 201605. https://doi.org/10.1063/1.4807436
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