Weak Hydrogen Bonds in Temporary Shape Changes of Curly Human Hair Fibers: Preliminary Evidence

Human hair curl has been widely explored, with dominating theories focusing on follicular shape, ultra-structural cortex patterns/ratios and intra-cellular interactions (Cloete et al. 2019). A few studies have observed hydration-driven shape memory in synthetic and animal keratin fibres, resulting in temporary, reversible shape changes (Quan et al. 2021). Hydrogen bonds (H-bonds) have been implicated but molecular level mechanisms and direct measurement techniques remain open challenges.