一种新的氨基酸基有机无机杂化水凝胶

A Novel Amino-Acid-Based Inorganic-Organic Hybrid Hydrogel

针对传统有机凝胶力学性能差、响应速率低的问题,设计合了氨基酸衍生低聚肽与硅烷的有机无机杂化水凝胶。选择低聚肽(TEA)与硅烷作为杂化前驱体,并在体系引入亲水的羧基普朗尼克,TEA与羧基化普朗尼克在分子间氢键以及芳基堆砌作用下,自组装超分子体系,这一超分子体系阻碍了硅烷的缩聚,破坏了GPTMS(环氧硅烷)的自聚合,形成了有别于传统倍半硅烷的超分杂化水凝胶。采用傅里叶红外光谱仪、扫描电子显微镜、热重分析仪、电子万能试验机等测试方法分析表征了杂化水凝胶内部的超分子作用、凝胶的断面及表面形貌、凝胶的热分解性能及不同老化时间干燥凝胶的抗压性能。结果表明,TEA的引入,有效地干预了硅烷水解后的自缩聚的笼状结构;TEA的氨基的得环氧硅烷水解后环氧端部分开环,与TEA缩聚,形成有机网络,而羧基化的普朗尼克之间在分子间作用力下形成了超分子自组装体系;自组装体系的力学性能取决于老化时间,老化24 h的凝胶具有最高抗压强度8.6 MPa。

A type of novel organic-inorganic hybrid hydrogels were designed and synthesized by mixing the amino acids derived oligopeptides with 3-glycidoxypropyltrimethoxysilane(GPTMS).Considering the fact that the presence of closed cage POSS may result in unexpected swelling and biodegradability by silane condensation,hydrophilic carboxylized Pluronic was introduced to avoid the formation of POSS.Triethylamine(TEA)and carboxylized Pluronic were self-assembled into a supramolecular system with the aid of the intermolecular hydrogen bond andπ-πstacking.Such a supramolecular system hindered the condensation polymerization of silane and disrupted the self-polymerization of GPTMS.The transversal and surface morphologies and chemical structure of the hybrid hydrogels were characterized by FTIR and SEM,their thermal degradability was characterized by TG,and their compression performance after aging for different time was measured by an electronic universal testing machine.The results indicated that the introduction of oligopeptides could hinder the self-condensation of GPTMS into the cage structure,and the epoxy groups of GPTMS reacted with the active hydrogen of TEA to form an organic network.The carboxylated Pluronic could help to form a supramolecular self-assembly system with TEA by the intermolecular force.Moreover,the self-assembled system exhibited a dependency of mechanical performance on the aging time,and it presented highest compressive strength of 8.6 MPa after aging for 24h.