The N-isopropyl acrylamide (NIPAM) and acrylic acid (AAc) copolymer (P (NIPAM-co-AAc)) microgel was prepared through soap-free emulsion polymerization. The morphology and the transmittance of P (NIPAM-co-AAc) microgel before and after loading protein of bovine serum albumin (BSA) were observed by atomic force microscopy (AFM) and spectrophotometer, respectively. AFM image showed that the particle size of the microgel was about 900 nm in contrast with 20 nm of BSA particles. It was also found that from AFM, the P (NIPAM-co-AAc) microgel particles were uniformly dispersed with a conical shape, while the BSA-loaded microgel particles formed agglomerates and the microgel particles were distributed in a cylindrical shape, which was caused by the significant improvement of microgel particles after protein adsorption. The changes of surface properties ultimately influenced the lower critical solution temperature (LCST) of microgel solutions, leading to a decrease in the LCST of the BSA-loaded microgel solution.

的Ñ -异丙基丙烯酰胺（NIPAM）和丙烯酸（AAC）共聚物（P（NIPAM-共-AAc））微凝胶是通过无皂乳液聚合制备。用原子力显微镜（AFM）和分光光度计分别观察了牛血清白蛋白（BSA）上样前后P（NIPAM- co- AAc）微凝胶的形貌和透射率。AFM图像显示微凝胶的粒度为约900nm，而BSA颗粒为20nm。还发现，从AFM中，P（NIPAM- co-AAc）微凝胶颗粒以圆锥形均匀分散，而负载BSA的微凝胶颗粒形成团聚物，并且微凝胶颗粒呈圆柱状分布，这是由于蛋白质吸附后微凝胶颗粒的显着改善引起的。表面性质的变化最终影响了微凝胶溶液的较低临界溶液温度（LCST），导致BSA负载的微凝胶溶液的LCST降低。