Combined effect of chain length and phase state on adhesion/friction behavior of self-assembled monolayers.
The combined effects of phase state and chain length on the adhesion and friction behavior of self-assembled monolayers (SAMs) are demonstrated using atomic force microscopy (AFM). The phase state of n-alkyltrichlorosilane monolayers of varying chain length (C-8, C-12, and C-18) was controlled by adjusting the preparation temperature. The adhesion forces and friction coefficients were observed to increase dramatically around the phase-transition temperature of each monolayer. The phase state effect was more prominent for the longer chain SAMs, which is attributed to the larger deformation volume associated with disordered monolayers. The adhesion/friction diagram for chain length effect with a wide range of phase states is successfully presented. This study reveals that the chain length effect on adhesion/friction can be correctly evaluated by examining the phase-state dependence of adhesion/friction behind the chain length effect.
Lee
Dae Ho
DH
Department of Chemical Engineering, School of Environmental Science and Engineering, Polymer Research Institute, Pohang University of Science and Technology, Pohang 790-784, South Korea.
Oh
Taebyoung
T
Cho
Kilwon
K
D000268:Adhesiveness; D017276:Friction; D007202:Indicators and Reagents; D008567:Membranes, Artificial; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D012821:Silanes; D013055:Spectrophotometry, Infrared; D013696:Temperature
D007202:Indicators and Reagents; D008567:Membranes, Artificial; D012821:Silanes