盐对刷型两亲聚合物聚集行为的调控作用

摘要

The extraordinary properties of amphiphilic polymers originate from their unique skeleton structures and the aggregation behavior of the polymer chains. In the present work, we introduced different amounts of NaCl into AMPS-AMC12S brush-like amphiphilic polymers synthesized via the statistical polymerization of 2-(acrylamido)-dodecanesulfonic acid (AMC12S) with 2-(acrylamido)-2-methylpropanesulfonic acid (AMPS), and investigated the effects of the NaCl on the aggregation behavior of the polymers, using steady-state fluorescence, dynamic light scattering, and transmission electron microscopy. The results showed that the effects of the salt were more intense for polymers with fewer side chains. As the NaCl concentration increased, the polymer chains associated at a lower critical concentration. The polymers tended to aggregate in an intrapolymer configuration, in preference to an interpolymer configuration; this resulted in the formation of smal er unimers, rather than giant multipolymer aggregates. The results described here provide an efficient approach for control ing the aggregation behavior of amphiphilic polymers, and have significance in advancing the design and control of functional aqueous systems, as wel as in promoting the development and application of novel polymers.%　　两亲聚合物奇异的功能特性源于分子独特的骨架结构和在溶液中的自组装聚集行为。本文向以2-丙烯酰胺基-十二烷基磺酸(AMC12S)与2-丙烯酰胺基-2-甲基丙磺酸(AMPS)进行无规共聚所制备的AMPS-AMC12S刷型两亲聚合物溶液体系中引入不同用量的NaCl,采用稳态荧光、动态光散射(DLS)和透射电子显微镜(TEM)系统考察NaCl对聚合物聚集行为的调控作用。研究发现,聚合物结构中疏水侧链含量越低, NaCl对聚集行为的调控作用越强； NaCl浓度增加会明显降低聚合物的临界聚集浓度；与此同时,聚合物分子链自组装由分子间的聚集方式向分子内的聚集方式转变,形成的聚集形态由大型多分子聚集体变化为尺寸数百分之一的单聚体。