Preparation and Tribological Property of Novel Self-Assembled Composite Films on Silicon

Abstract

Self-assembled composite films of APTES-GA-APTES were successfully prepared on single-crystal silicon substrates through the cross-linking reaction between glutaraldehyde (GA) and two layers of 3-aminopropyltriethoxysilane (APTES). The optimal time to deposit the GA layer on the APTES monolayer was 3 h, during which most amino groups of APTES reacted with the aldehyde groups of GA to form smooth and uniform APTES-GA composite films. The further deposition of another APTES layer led to the generation of three-layer APTES-GA-APTES composite films. Compared to the APTES self-assembled monolayers, the three-layer films displayed a similar surface morphology but a reduced friction coefficient from 0.23 to 0.15 and an extended wear life from 50 s to 820 s due to the introduction of GA.