摘要
Phase transition of hydrogel,which is polymerized by polymer network,can be regarded as the transition of polymer network stability.The stability of the polymer network might be changed when the external environment changed.This change will lead to the transformation of sensitive hydrogels stability,thus phase transition of hydrogel take place.Here,we present a new free density energy function,which considers the non-gaussianity of the polymer network,chains entanglement and functionality of junctions through adding Gent hyplastic model and Edwards-Vilgis slip-link model to Flory-Huggins theory.A program to calculate the phase transition temperature was written based on new free energy function.Taking PNIPAM hydrogel as an example,the effects of network entanglement on the phase transition temperature of hydrogel were studied by analyzing the microstructure parameters of the hydrogel networks.Analytical results suggest a significant relationship between phase transition temperature and entanglement network.
基金
support from the National Natural Science Foundation of China(Grant Nos.11520007,11572109 and 11632005)
the Hebei Natural Science Foundation of China(Grant No.A2016201198)
technology research in Colleges and Universities of Hebei Province(Grant No.ZD2017006)are gratefully acknowledged。