作者:Jun-Ha Park、Min-Soo Kim、Sang-Hyuk Seo、Ji-Young Chang
DOI:10.5012/bkcs.2011.32.7.2193
日期:2011.7.20
We prepared polycatenar 1H-imidazole amphiphiles having a structure in which a 1H-imidazole head was connected through a benzene ring to a pheny group having two or three oligo(ethylene glycol) chains and studied their supramolecular assembly by fluorescence spectroscopy, transmission electron microscopy (TEM) and atomic force microscopy (AFM). When the aqueous solutions of the amphiphiles ($5\times}10^-5}M\sim}10^-3}M$) were deposited onto a carbon-coated copper grid and dried, twisted structures with diameters of ~200-300 nm were imaged by TEM and AFM. We presume that the structures comprised a chain of the amphiphile dimers formed via successive hydrogen bonding between the 1H of the imidazole group and 3N of the neighboring one. In a solution of pH 4, entangled fibers with diameters of several nanometers were observed by TEM. In a pH 10 solution, film-like aggregates formed exclusively. The 1H-imidazole amphiphiles hydrolyzed tetraethoxysilane to induce gelation to form fibrous and spherical silica structures at neutral pH in aqueous solutions. No silica was formed when imidazole was used instead of the amphiphiles, suggesting that the selfassembled aggregates of the amphiphiles were responsible for the gelation.
我们制备了具有特定结构的聚并咪唑表面活性剂,其结构为1H-咪唑头通过苯环连接到一个含有两到三条聚乙二醇链的苯基上,并通过荧光光谱学、透射电子显微镜(TEM)和原子力显微镜(AFM)研究了它们的超分子组装。当这些表面活性剂的水溶液($5\times}10^-5}M\sim}10^-3}M$)沉积在碳涂层铜网上并干燥后,通过TEM和AFM观察到直径约为200-300纳米的扭曲结构。我们推测这些结构由通过连续的氢键形成的表面活性剂二聚体链组成,这些氢键是在咪唑基团的1H和邻近基团的3N之间形成的。在pH为4的溶液中,通过TEM观察到直径为数纳米的缠结纤维。在pH为10的溶液中,仅形成了膜状聚集物。1H-咪唑表面活性剂水解四乙氧基硅烷,在水中性pH下诱导凝胶化,形成纤维状和球形的二氧化硅结构。当使用咪唑代替表面活性剂时,没有形成二氧化硅,这表明表面活性剂的自组装聚集体负责凝胶化过程。