| 초록 |
A radical polymerization of poly(ethylene glycol) diacrylate (PEGDA) below the overlap concentration is known to create a phase-separated polymer network. When the phase-separated hydrogels underwent the drying and reswelling processes, we found that the equilibrium swelling of the hydrogels was irreversibly reduced, which we called the swelling hysteresis. The chemical analysis of the reswollen hydrogels has confirmed the absence of chemical reactions during the drying and reswelling processes. Based on dSTORM, SAXS, and TD-NMR experiments as well as the molecular dynamics (MD) simulations, we suggest that the elastically inactive dangling chains in the form of a hyper-branched structure present near the phase boundaries, where the monomer conversion approaches the critical gel point, were irreversibly entangled during the drying process, resulting in the swelling hysteresis. |
