Controlled Nanoparticle Size Modifications and Functionalizations through controlled polymeric Nanonetwork Expansion

由有机网络组成的塑料是最广泛使用的材料之一。然而，大多数聚合物网络一旦形成就很难操作。休斯顿大学的Eva Harth教授的研究小组旨在开发强大的合成方法，用于制造微小的有机网络结构（尺寸比头发的宽度小得多），并能够将母结构修改成各种不同大小和功能的其他网络。添加功能、修改组成或扩展网络以允许修复的能力将扩大纳米级聚合物网络的应用范围。这个跨学科的项目教育STEM领域的研究生和本科生。即将升学的高三学生和高年级学生有机会通过韦尔奇暑期学者计划参与这项研究。本项目主要研究光响应纳米材料的制备及其在尺寸、分子量和化学官能团方面的操作。Harth教授的研究团队正在建立方法，用各种可降解和不可降解的聚合物骨架和含有三硫代碳酸盐单元的交联单元合成可光生长的纳米网络。在有或没有光氧化还原催化剂的情况下，光诱导聚合被用于动态生长，以扩大网络并将功能单体引入现有的沙子中。这些扩张过程的光控制自由基聚合的条件进行了彻底的研究，因为这些决定了网络的最终分散性。最终，本研究旨在测试光控自由基聚合技术的操作能力和范围，从而产生下一代纳米和微米尺度的网络材料。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Plastics that are composed from organic networks are one of the most widely used materials. However, most polymer networks are difficult to manipulate once the material is formed. The research group of Professor Eva Harth at the University of Houston aims to develop robust synthetic methods for the fabrication of tiny organic network structures (of dimensions much smaller than the width of hair) with the ability to modify a parent structure into various other networks of different sizes and functions. The ability to add functions to, modify composition of, or expand the network to allow for repair would broaden the applications of nano-scale polymer networks. This interdisciplinary project educates graduate and undergraduate students in STEM fields. Rising high school seniors and seniors have the opportunity to engage in this research through the Welch Summer Scholars Program.This project focuses on the preparation of photoresponsive nanomaterials and their manipulation in dimension, molecular weight and chemical functional groups. The research team of Professor Harth is establishing methods to synthesize photogrowable nanonetworks from a variety of degradable and non-degradable polymer backbones and cross-linking units containing trithiocarbonate units. Photoinduced polymerizations in the presence and absence of photoredox catalysts are utilized for the dynamic growth to expand the networks and introduce functional monomers into the existing schaffolds. Conditions of photo-controlled radical polymerizations for these expansion processes are thoroughly investigated as these determine the final dispersity of the network. Ultimately, this research is directed to test the capability and range of manipulation which is possible by applying photo-controlled radical polymerization techniques to generate the next generation of nano- and micron scale network materials.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.