Tuning Aqueous Micellar Gels and Nanoparticle-Containing Hybrid Micellar Gels of Thermosensitive Hydrophilic Block Copolymers

技术概述：近年来，由于环境触发引起的原位溶胶-凝胶转变，刺激响应型亲水性嵌段共聚物的水性胶束凝胶引起了越来越多的兴趣。这些物理凝胶在许多技术应用中具有巨大的潜力。本项目旨在研究调整双热敏嵌段共聚物的水性胶束凝胶和热敏嵌段共聚物与纳米颗粒的水性杂化胶束凝胶的结构和性能的策略。通过“活的”/可控自由基聚合技术，将合成一系列定义良好的多响应亲水性嵌段共聚物和聚合物电刷接枝纳米颗粒（“毛状纳米颗粒”）。研究了这些嵌段共聚物和毛状纳米颗粒在水溶液中的响应特性。在低/中等浓度范围内，在毛状纳米颗粒存在和不存在的情况下，热敏嵌段共聚物的溶胶-凝胶相图将被确定，凝胶结构将被阐明。本研究将采用广泛的表征技术，包括光散射、流变学、荧光光谱、小角x射线散射、差示扫描量热法和电子显微镜。从这项研究中获得的知识将为设计具有可调结构和性能的新型多响应嵌段共聚物胶束凝胶和杂化胶束凝胶提供基础。非技术概述：该项目涉及创建特殊类别的水溶性凝胶，形成胶束和纳米颗粒。这些新材料将被设计成对各种外部刺激做出反应，并可能在物质的持续和触发释放方面有潜在的应用。此外，该研究项目为培养研究生和本科生通过广泛的技术合成和表征各种新分子和纳米结构以及设计刺激响应的软质和混合材料提供了坚实的平台。学生将有机会深入了解合成、结构和性质之间的关系。PI将继续他的努力，为诺克斯维尔田纳西大学化学系的高分子化学入门课程开发和丰富一个实验室组件。PI还将积极帮助K-12教育中的科学教学。他和他的研究生将通过暑期项目与当地高中教师和学生在他的实验室合作，为他们的化学课开发实验室实验。

TECHNICAL SUMMARY:Aqueous micellar gels of stimuli-responsive hydrophilic block copolymers have attracted growing interest in recent years due to the intriguing in situ sol-gel transitions induced by environmental triggers. These physical gels have great potential in many technological applications. This project is aimed at developing strategies to tune structures and properties of aqueous micellar gels of doubly thermosensitive block copolymers and of aqueous hybrid micellar gels of thermosensitive block copolymers and nanoparticles. A series of well-defined multi-responsive hydrophilic block copolymers and polymer brush-grafted nanoparticles ("hairy nanoparticles") will be synthesized by using "living"/controlled radical polymerization techniques. The responsive properties of these block copolymers and hairy nanoparticles in aqueous solutions will be examined. The sol-gel phase diagrams of thermosensitive block copolymers in low/moderate concentration ranges in the absence and presence of hairy nanoparticles will be determined, and the gel structures will be elucidated. A wide range of characterization techniques will be employed in this research, including light scattering, rheometry, fluorescence spectroscopy, small angle X-ray scattering, differential scanning calorimetry, and electron microscopy. The knowledge gained from this research will provide a basis for the design of a new class of multi-responsive block copolymer micellar gels and hybrid micellar gels with tunable structures and properties for technological applications. NON-TECHNICAL SUMMARY:This project involves creating special categories of water-soluble gels that form micelles and nanoparticles. These new materials will be designed to respond to a variety of external stimuli and could have potential applications for sustained and triggered release of substances. Moreover, this research project provides a solid platform for training graduate and undergraduate students to synthesize and characterize a variety of new molecules and nanostructures by a broad range of techniques and to design stimuli-responsive soft and hybrid materials. Students will have an opportunity to gain a deep understanding of relationships among synthesis, structures, and properties. The PI will continue his effort to develop and enrich a laboratory component for the introductory polymer chemistry course in the Department of Chemistry at the University of Tennessee, Knoxville. The PI will also be active in helping science teaching in K-12 education. He and his graduate students will work with local high school teachers and students in his laboratory through summer programs to develop laboratory experiments for their chemistry classes.