聚合物水凝胶体积相变过程中自发生成的新图案  

A Novel Macroscopic Pattern Formation During Volume Phase Transition of Polymeric Hydrogel

作　　者：纪仕辰[1] 丁建东[1] 

机构地区：[1]复旦大学高分子科学系,聚合物分子工程教育部重点实验室,上海200433

出　　处：《高等学校化学学报》2001年第7期1254-1255,共2页Chemical Journal of Chinese Universities

基　　金：国家杰出青年科学基金 (批准号 :2 982 5 10 9);国家重点基础研究发展规划项目资助

摘　　要：Pattern formation in polymeric hydrogel associated with volume phase transition was observed in strong gel shrinking. Chemically cross linked poly(sodium acrylate/acrylamide) gel was prepared and shaped by capillary. The gel cylinder was suddenly dipped into acetone or into an acid aqueous solution. The former exhibited bamboo like pattern, similar to the report in the literature. But a novel pattern, gel helix or gel spring, was found in the latter case. Macroscopic patterns only occurred in a strong gel collapse, and nothing was found in a step by step volume shrinking. The helix is with period between 0 1 to 1 mm and formed within 100 second. Both right hand sense and left hand sense could be obtained. Once formed, the gel helix cannot be recovered by re swelling in basic solution. Surface crack and its helical growth were observed and could account for the formation of gel helix preliminarily.Pattern formation in polymeric hydrogel associated with volume phase transition was observed in strong gel shrinking. Chemically cross linked poly(sodium acrylate/acrylamide) gel was prepared and shaped by capillary. The gel cylinder was suddenly dipped into acetone or into an acid aqueous solution. The former exhibited bamboo like pattern, similar to the report in the literature. But a novel pattern, gel helix or gel spring, was found in the latter case. Macroscopic patterns only occurred in a strong gel collapse, and nothing was found in a step by step volume shrinking. The helix is with period between 0 1 to 1 mm and formed within 100 second. Both right hand sense and left hand sense could be obtained. Once formed, the gel helix cannot be recovered by re swelling in basic solution. Surface crack and its helical growth were observed and could account for the formation of gel helix preliminarily.

关 键 词：聚合物水凝胶 体积相变 图案生成 螺旋状图案 

分 类 号：O631.1[理学—高分子化学] O648.17[理学—化学]