초록 |
A radical polymerization below the overlap concentration is known to create a phantom network, and phase separated structure due to incomplete polymerization. When the phase separated hydrogel underwent the drying and reswelling processes, equilibrium swelling of the hydrogels was irreversibly reduced and became more transparent, which we called the drying induced hysteresis. Chemical analysis of the hysteresis occurred hydrogels has confirmed the absence of chemical reactions during the drying and reswelling processes through ssNMR, MALDI-TOF, Raman. Based on dSTORM, SAXS, LAOS, and TD-NMR experiments as well as the molecular dynamics (MD) simulations, we suggest that the elastically inactive dangling chains at the edge of the phase boundary, form a hyper-branched structure due to low polymer concentration, were irreversibly entangled during the drying process, resulting in the swelling hysteresis. |