制备了侧链含α-环糊精(α-CD)的聚丙烯酸(PAA-α-CD)作为主体聚合物,侧链含偶氮基团(Azo)的聚丙烯酰胺(PAM-Azo)作为客体聚合物。利用1 H NMR、2DNOESY NMR方法测定了PAA-α-CD与PAM-Azo间的主客体作用。结果表明,PAM-Azo侧链的trans-Azo基团能够被PAA-α-CD侧链的α-CD包结,而cis-Azo基团不能被α-CD包结。在一定浓度下,PAA-α-CD与PAM-Azo通过主客体间的识别能够形成超分子水凝胶,并且该凝胶具有光响应性。在365nm紫外光光照下,PAM-Azo侧链的trans-Azo转变为cis-Azo,不能被PAA-α-CD侧链的α-CD包结,超分子水凝胶转变为溶胶。而在430nm的可见光光照下,PAM-Azo侧链的cis-Azo转变为trans-Azo,重新被PAA-α-CD侧链的α-CD包结,又可得到超分子水凝胶。
The cloudy Silwet L-77 aqueous solution on the concentration range from 0.5%to 50%was investigated by dielectric relaxation spectroscopy.The concentration dependence of phase microstructure was confirmed by means of analyzing the dielectric parameters of bulk solution.The relaxation behavior was assigned to the interfacial polarization between the micelle and the medium,and the relaxation distribution parameter was used to figure the shape transition from sphere to ellipsoid with the concentration increasing.The synchronous reduction of permittivity and conductivity indicated the formation of the lamellar phase. As compensation,the quantity of the surfactant liquid phase gradually decreased,whose shape constantly kept ellipsoidal.
