Modeling hair lubrication in the presence of additives

该项目将研究在无硅护发素和无硫酸盐洗发水中使用的新添加剂存在的情况下，头发与头发接触中湿摩擦的分子水平相互作用和基本机制。将特别强调对环境影响较小的天然产品。分子动力学（MD）和非平衡分子动力学（NEMD）模拟将用于研究表面活性剂、聚合物和天然产物存在下毛发表面化学的变化及其对毛发润滑的影响。我们还将探索使用基于连续体的模型和混合分子连续体模拟来捕捉由改进配方引起的表面变化对宏观尺度摩擦的影响。该项目将利用我们最近为人类头发表面开发的粗粒度分子模型来重现其摩擦特性[2,3]Weiand et al.，软物质，202,18,1779 (https://doi.org/10.1039/D1SM01720A)[2] Weiand et al.，纳米尺度，2023,15,7086 （https://doi.org/10.1039/D2NR05545G)[3] Handa，化学世界，2023 (https://www.chemistryworld.com/news/study-untangles-friction-and-surface-chemistry-in-chemically-damaged-hair/4017403.article)）

This project will study the molecular-level interactions and fundamental mechanisms responsible for wet friction in hair-to-hair contacts in the presence of new additives used in silicone-free conditioners and sulfate-free shampoos. Particular emphasis will be placed upon natural products with lower environmental impact. Molecular Dynamics (MD) and Non-Equilibrium Molecular Dynamics (NEMD) simulations will be used to study changes on the hair surface chemistry in presence of surfactants, polymers, and natural products and their impact on hair-hair lubrication. We will also explore the use of continuum-based models and hybrid molecular-continuum simulations to capture the impact of the surface changes induced by the improved formulations on macroscale friction.The project will utilise coarse-grained molecular models that we have recently developed for the surface of human hair [1] that reproduce its friction properties [2,3].[1] Weiand et al., Soft Matter, 2022, 18, 1779 (https://doi.org/10.1039/D1SM01720A)[2] Weiand et al., Nanoscale, 2023, 15, 7086 (https://doi.org/10.1039/D2NR05545G)[3] Handa, Chemistry World, 2023 (https://www.chemistryworld.com/news/study-untangles-friction-and-surface-chemistry-in-chemically-damaged-hair/4017403.article)