Our doctoral student Zheng Huang, under the joint supervision of Researcher Liangbin Li and Postdoctoral Fellow Jungeng Chen, has conducted research on the processing of nanofiber membranes using high-temperature stretched PVA–glycerol hydrogel films. The study focused on the in-situ structural evolution and influencing factors of various hydrogel films stretched at different temperatures. The related work has been published in the journal Macromolecules.
In this article, in-situ small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) were employed to investigate the structural evolution of glycerol-containing PVA hydrogel films during stretching at different temperatures. SAXS and WAXS analyses revealed that uniaxial stretching induced melt-recrystallization of PVA lamellar crystals and the formation of nanofibers. The key factors driving structural evolution varied with stretching temperature. At lower temperatures, crystal disruption was primarily stress-induced. The reconstructed nanofibers could bear stress and feed back into the structural evolution process, thereby slowing crystal damage. Under high-temperature conditions, crystal disruption occurred mainly through melting, with a rapid decline in crystallinity under stress. However, stretching-induced recrystallization and nanofiber reconstruction were more readily achieved. In addition, the long period of lamellar crystals and nanofibers increased with the stretching temperature. Moreover, PVA porous nanofiber membranes with well-developed nanofiber networks and porous structures were obtained through biaxial stretching, solvent extraction, and drying.
This work was supported by the Major Science and Technology Project of Hefei City, Anhui Province (“Revealing the List and Taking Command,” Project No. 2022-SZD-005), and the Chinese Academy of Sciences (Grant No. JZHKYPT-2021-04).
Huang Z, Li W, Wan C, et al. Stretch-Induced Structure Evolution of Poly(vinyl alcohol)–Glycerol Gel Films: An In Situ Synchrotron Radiation X-ray Scattering Study [J]. Macromolecules, 2025.
Paper link：https://pubs.acs.org/doi/10.1021/acs.macromol.5c00354
