模型化研究高分子凝胶体积相变中的共非溶性作用.

Based on the Flory - Huggins theory, we built a theoretical model to study the role of co- nonsolvency in the volume phase transition of polymer gel(PG) in co- nonsolvent (CNS). The theoretical model considers the bridging effect of CNS in PG and the miscibility effects of various molecules. We found that when the attraction strength between CNS and polymer monomer is low, the bridging effect between CNS and polymer monomer is weakened, which will lead to the volume phase transition of PC. When the attraction between CNS and polymer monomer is strong, with the weakening of the bridging between CNS and polymer monomer, the volume fraction of PG presents two step transitions, indicating that the PC presents two volume transitions. Because of the weakening of the bridging effect, although some CNS molecules will be squeezed out of the gel, the bridging attraction between CNS and polymer monomer has not been completely eliminated. The theoretical results are consistent with the experimental observations, which indicates that the phase transition behavior of PG can be con- trolled to a large extent by the co-nonsolvency. [ABSTRACT FROM AUTHOR]