Increased molecular mobility in humid silk fibers under tensile stress
Silk fibers are semicrystalline nanocomposite protein fibers with an extraordinary mechanical toughness that changes with humidity. Diffusive or overdamped motion on a molecular level is absent in dry silkworm silk, but present in humid silk at ambient temperature. This microscopic diffusion distinctly depends on the externally applied macroscopic tensile force. Quasielastic and inelastic neutron-