AFM Studies on Liquid Superlubricity between Silica
Surfaces Achieved with Surfactant Micelles
Jinjin Li
Chenhui Zhang
Peng Cheng
Xinchun Chen
Weiqi Wang
Jianbin Luo
10.1021/acs.langmuir.6b01237.s001
https://acs.figshare.com/articles/journal_contribution/AFM_Studies_on_Liquid_Superlubricity_between_Silica_Surfaces_Achieved_with_Surfactant_Micelles/3405235
By
using atomic force microscopy (AFM), we showed that the liquid
superlubricity with a superlow friction coefficient of 0.0007 can
be achieved between two silica surfaces lubricated by hexadecylÂtrimethylÂammonium
bromide (C<sub>16</sub>TAB) solution. There exists a critical load
that the lubrication state translates from superlow friction to high
friction reversibly. To analyze the superlow friction mechanism and
the factors influencing the critical load, we used AFM to measure
the structure of adsorbed C<sub>16</sub>TAB molecules and the normal
force between two silica surfaces. Experimental results indicate that
the C<sub>16</sub>TAB molecules are firmly adsorbed on the two silica
surfaces by electrostatic interaction, forming cylinder-like micelles.
Meanwhile, the positively charged headgroups exposed to solution produce
the hydration and double layer repulsion to bear the applied load.
By controlling the concentration of C<sub>16</sub>TAB solution, it
is confirmed that the critical load of superlow friction is determined
by the maximal normal force produced by the hydration layer. Finally,
the superlow friction mechanism was proposed that the adsorbed micellar
layer forms the hydration layer, making the two friction surfaces
be in the repulsive region and meanwhile providing excellent fluidity
without adhesion between micelles.
2016-05-18 00:00:00
load
superlow friction mechanism
micellar layer forms
superlow friction
Silica Surfaces Achieved
hydration layer
C 16 TAB molecules
AFM
C 16 TAB solution
superlow friction coefficient
silica surfaces
C 16 TAB