Self-assembled structures of a semi-rigid polyanion in aqueous solutions and hydrogels  

作　　者：SUN TaoLin WU ZiLiang GONG JianPing 

机构地区：[1]Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan [2]Faculty of Advanced Life Science, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan

出　　处：《Science China Chemistry》2012年第5期735-742,共8页中国科学（化学英文版）

基　　金：supported by a Grant-in-Aid for the Specially Promoted Research (18002002) from the Ministry of Education, Science, Sports and Culture of Japan

摘　　要：Poly(2,2'-disulfonyl-4,4'-benzidine terephthalamide) (PBDT), a kind of liquid-crystalline (LC) molecule, has high molecular weight, negative charge and a semi-rigid structure. The aqueous solution of PBDT shows nematic liquid crystalline state above a critical PBDT concentration, CLC*, of 2 wt%-3wt%. Different from the flexible polyelectrolyte, PBDT shows a variety of self-assembling structures in aqueous solution with and without salt due to the semi-rigid nature and highly charged property. In addition, the hydrogels with ordered structure are developed by polymerizing a cationic monomer N-[3-(N,N-dimethylamino) propyl] acrylamide methyl chloride quarternary (DMAPAA-Q) in the presence of a small amount of PBDT below the CLC*. During the polymerization of cationic monomer, the polycations form a complex with semi-rigid PBDT through electrostatic interaction; these complexes self-assemble into ordered structures that are frozen in the hydrogel. Several different structures, including the anisotropic, dual network-like structure, and cylindrically symmetric structure, with various length scales from micrometer to millimeter, are observed. The hydrogels with ordered liquid crystalline assemblies and particular optical properties should promise applications in many fields, such as in bionics, tissue engineering, and mechano-optical sensors.Poly（2,2＇-disulfonyl-4,4＇-benzidine terephthalamide） （PBDT）, a kind of liquid-crystalline （LC） molecule, has high molecular weight, negative charge and a semi-rigid structure. The aqueous solution of PBDT shows nematic liquid crystalline state above a critical PBDT concentration, CLC＊, of 2 wt%-3wt%. Different from the flexible polyelectrolyte, PBDT shows a variety of self-assembling structures in aqueous solution with and without salt due to the semi-rigid nature and highly charged property. In addition, the hydrogels with ordered structure are developed by polymerizing a cationic monomer N-[3-（N,N-dimethylamino） propyl] acrylamide methyl chloride quarternary （DMAPAA-Q） in the presence of a small amount of PBDT below the CLC＊. During the polymerization of cationic monomer, the polycations form a complex with semi-rigid PBDT through electrostatic interaction; these complexes self-assemble into ordered structures that are frozen in the hydrogel. Several different structures, including the anisotropic, dual network-like structure, and cylindrically symmetric structure, with various length scales from micrometer to millimeter, are observed. The hydrogels with ordered liquid crystalline assemblies and particular optical properties should promise applications in many fields, such as in bionics, tissue engineering, and mechano-optical sensors.

关 键 词：HYDROGELS SELF-ASSEMBL POLYELECTROLYTE SEMI-RIGID polyion complex 

分 类 号：O485[理学—固体物理] U674.78[理学—物理]