Coarse-grained molecular simulations of interfaces between fluid formulations and soft biomimetic surfaces
File(s)
Author(s)
Weiand, Erik
Type
Thesis
Abstract
A paradigm shift in the development of new hair and personal care products is required to keep up with increasing demands for more sustainable and biocompatible formulations while further pushing the boundaries of the product performance. Molecular modelling approaches are deemed a strong candidate for accelerating the early stage development of such new formulations. This work introduces a new coarse-grained molecular dynamics framework for enabling the virtual screening of nanoscale hair friction and more generally soft surface friction for the first time. A new molecular model of the F-layer of human hair is presented and validated against new and existing structural and wetting experiments. Non-equilibrium molecular dynamics simulations are then coupled to preliminary squeeze-out simulations for an accurate load-dependent contact composition to screen the tribological performance of hair surfaces under varying degrees of chemical damage. Bare surfaces and surfaces with adsorbed small ionic compounds and poly-electrolytes commonly used in hair care products are considered. These simulations aim at uncovering new boundary lubrication mechanisms of cationic surfactants and oppositely charged polyelectrolyte-surfactant aggregates on healthy and damaged biomimetic hair surfaces which is beneficial for tuning the deposition behaviour of new formulations. Finally, the developed methodology is implemented and expanded in an automation tool for high-throughput virtual screening of the nanoscale friction of soft surfaces such as cotton cellulose.
Version
Open Access
Date Issued
2024-03-31
Date Awarded
01/08/2024
License URL
Advisor
Ewen, James P.
Angioletti-Uberti, Stefano
Dini, Daniele
Sponsor
Engineering and Physical Sciences Research Council
The Procter & Gamble Company (Firm)
Grant Number
EP/T517690/1
Publisher Department
Mechanical Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)