The Self-Recovery Phenomenon of Oxidized Hair

The study investigated the structural changes in oxidized hair, focusing on the mechanical and thermal stability of hair fibers composed of keratin intermediate filaments (IFs) and an amorphous matrix. Using Differential Scanning Calorimetry (DSC), it was found that moderate oxidative treatments decreased the integrity of the matrix and matrix-IF interface, while intensive oxidative treatments affected the crystalline regions of the microfibrils. Over six months, oxidized hair exhibited a "self-recovery phenomenon," where it regained thermal and mechanical stability, indicated by a rising denaturation temperature and increasing tensile modulus, suggesting a reorganization of the matrix and reinforced interactions between matrix and microfibrils.