Studies on Molecular Interactions of Charged Poymer Gels

(1)讨论了离子络合聚合物凝胶（ICPG）的结构与流变性能的关系。通过溶胀实验和毛细管粘度法分别测定了ICPG的溶胀率和相应聚合物溶液的粒径，发现了两者的相似之处。发现Donnan电位在决定ICPG肿胀率中起重要作用。(2)弱带电温敏聚合物凝胶对聚n -异丙基丙烯酰胺-共丙烯酸（NIPA/AAc）凝胶进行了小角中子散射研究。NIPA/AAc凝胶与相应的聚合物溶液的静态结构因子有明显差异。在凝胶的情况下，形成了微相分离，而在NIPA/AAc聚合物溶液中观察到微相和大相分离。NIPA/AAc中巨相分离的缺失是由于凝胶中缺乏平移自由度。用差示扫描量热法（DSC）定量分析了AAc共聚单体对疏水相互作用焓的依赖性。DSC中吸热曲线的起始温度与微相分离发生的温度一致。

(1)Ion-complexed polymer gels (ICPG) Correlation of the structure and rheological properties of ICPG has been discussed. The swelling ratio of ICPG and the size of the corresponding polymer solutions have been measured by a swelling experiment and capillary viscometry, respectively and an analogy is found between the two systems. It is found that Donnan Potential plays an important role in determining the swelling ratio for ICPG.(2)Weakly charged temperature sensitive polymer gels Small-angle neutron scattering (SANS) studies have been carried out on poly (N-isopropylacrylamide-co-acrylic acid) (NIPA/AAc) gels. A distinct difference in the static structure factors between NIPA/AAc gels and the corresponding polymer solutions has been observed. In the case of the gel, a microphase separation is exclusively formed, whereas both microphase and macrophase separation have been observed in NIPA/AAc polymer solutions. The absence of the macrophase separation in NIPA/AAc results from lack of translational freedom in the gel. Quantitative analysis for AAc comonomer dependence of the enthalpy of hydrophobic interaction has been also conducted by differential scanning calorimetry (DSC). The onset of an endothermic curve in DSC is consistent with the temperature at which microphase separation takes place.