Issue 15, 2023

Nanoscale friction of biomimetic hair surfaces


We investigate the nanoscale friction between biomimetic hair surfaces using chemical colloidal probe atomic force microscopy experiments and nonequilibrium molecular dynamics simulations. In the experiments, friction is measured between water-lubricated silica surfaces functionalised with monolayers formed from either octadecyl or sulfonate groups, which are representative of the surfaces of virgin and ultimately bleached hair, respectively. In the simulations, friction is monitored between coarse-grained model hair surfaces with different levels of chemical damage, where a specified amount of grafted octadecyl groups are randomly replaced with sulfonate groups. The sliding velocity dependence of friction in the simulations can be described using an extended stress-augmented thermally activation model. As the damage level increases in the simulations, the friction coefficient generally increases, but its sliding velocity-dependence decreases. At low sliding velocities, which are closer to those encountered experimentally and physiologically, we observe a monotonic increase of the friction coefficient with damage ratio, which is consistent with our new experiments using biomimetic surfaces and previous ones using real hair. This observation demonstrates that modified surface chemistry, rather than roughness changes or subsurface damage, control the increase in nanoscale friction of bleached or chemically damaged hair. We expect the methods and biomimetic surfaces proposed here to be useful to screen the tribological performance of hair care formulations both experimentally and computationally.

Graphical abstract: Nanoscale friction of biomimetic hair surfaces

Supplementary files

Article information

Article type
06 Oct 2022
22 Mar 2023
First published
23 Mar 2023
This article is Open Access
Creative Commons BY license

Nanoscale, 2023,15, 7086-7104

Nanoscale friction of biomimetic hair surfaces

E. Weiand, J. P. Ewen, Y. Roiter, P. H. Koenig, S. H. Page, F. Rodriguez-Ropero, S. Angioletti-Uberti and D. Dini, Nanoscale, 2023, 15, 7086 DOI: 10.1039/D2NR05545G

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity