P(AA-g-NIPAM)与PNIPAM间络合作用的荧光技术研究

利用UV透光率、荧光探针和荧光各向异性研究了稀水溶液中聚N-异丙基丙烯酰胺(PNIPAM)与接枝共聚物聚丙烯酸接枝聚N-异丙基丙烯酰胺P(AA-g-NIPAM)]间的络合作用. 结果表明, PNIPAM和P(AA-g-NIPAM)之间通过氢键作用形成络合物. 络合作用依赖于溶液pH及P(AA-g-NIPAM)接枝共聚物中AA的相对含量. 溶液pH越小, AA相对含量越高, 络合作用越强. 这种络合作用使得聚合物主链变得较为收缩, 体系亲水性降低, 表现出一定的疏水性.

Complexation between P(AA-g-NIPAM) and PNIPAM Studied by Fluorescence Techniques

The complexation between poly(acrylic acid-g-N-isopropylacrylamide) P(AA-g-NIPAM)] and poly(N-isopropylacrylamide) (PNIPAM) in an aqueous solution was studied by UV transmittance measurements, fluorescence probe and fluorescence anisotropy techniques. It was found that the complex was formed between the two polymers through hydrogen bonding interactions. Moreover, the complexation showed the dependence on pH values and the AA contents in the graft copolymers. The complexation became stronger with increasing AA contents in the graft copolymers and decreasing the solution pH value. This interaction made the polymer backbones shrink, meanwhile, the complex system exhibited hydrophobic properties, and its hydrophilic character was weakened.