Controlled Nanoparticle Size Modifications and Functionalizations through controlled polymeric Nanonetwork Expansion

由有机网络组成的塑料是使用最广泛的材料之一。然而，一旦材料形成，大多数聚合物网络就很难操纵。休斯顿大学伊娃·哈思教授的研究小组致力于开发强大的合成方法，以制造微小的有机网络结构(其尺寸远远小于头发的宽度)，并能够将母体结构修改为各种不同大小和功能的其他网络结构。对网络添加功能、修改组成或扩展网络以允许修复的能力将拓宽纳米级聚合物网络的应用。这个跨学科项目培养STEM领域的研究生和本科生。正在崛起的高中生和高年级学生有机会通过韦尔奇暑期学者计划从事这项研究。该项目专注于光响应性纳米材料的制备及其在尺寸、相对分子质量和化学官能团方面的操纵。哈思教授的研究团队正在建立一种方法，从各种可降解和不可降解的聚合物骨架和含有三硫代碳酸酯单元的交联单元合成可光生长的纳米网络。在光氧化还原催化剂存在和不存在的情况下，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到现有的分子筛中。对这些膨胀过程的光控自由基聚合条件进行了彻底的研究，因为这些条件决定了网络的最终分散性。最终，这项研究旨在测试通过应用光控自由基聚合技术来生成下一代纳米和微米级网络材料的操纵能力和范围。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.