Fig. 2: Retention of the complex hierarchical organization.
a, DSC curves of degummed silk and fused silk fabricated under different processing conditions. b,c, 2D SAXS patterns (b) and WAXS patterns (c) of degummed silk and fused silk fabricated at 215 °C and 1.0 GPa. d, Relative crystallinity of degummed silk and fused silk fabricated at different processing conditions, calculated from one-dimensional wide-angle X-ray diffraction profiles. Data are presented as mean ± s.d. (n = 3 independent samples). e, Herman’s orientation factor of the crystal plane (120), from 2D WAXS results. f, Content of protein secondary structures (β-sheet and random coil/α-helix) in degummed silk and fused silk materials fabricated at different conditions, from FTIR spectra. Data are presented as mean ± s.d. (n = 3 independent samples). The shaded area in d, e and f highlights the samples processed within this high temperature region, where silk undergoes severe thermal degradation. This degradation alters the amorphous phase and generates degradation products, leading to apparent increases in relative crystallinity and artificial shifts in FTIR-derived secondary structure content. g, Schematic of the mechanism of self-diffusion during the hot-pressing process.
