Mechanically Controlled Polymerization via Piezo-reduction of Copper

塑料是聚合物材料的一种形式，在重复使用后会分解。这种分解的原因之一是聚合物的化学键的断裂。Esser-Kahn教授研究了使用力或压力在塑料材料中产生新键的方法。 这些材料将能够从施加的力或压力中捕获能量，并使用它来引发聚合物链的生长或聚合物网络的形成以增强材料。 该项目包括研究和教育部分，以影响化学和工程学科中有关聚合物材料的基础知识。在化学系的高分子、超分子和纳米化学项目和材料研究系的聚合物项目的共同支持下，Esser-Kahn研究小组正在开发新的方法，将压电颗粒的反应作为在聚合物材料中产生新键的方法。在一个方向上，该项目研究了Cu（II）前体到Cu（I）活化剂的压电还原，该活化剂通过原子转移自由基聚合引发聚合物链的生长。 在第二个方向上，压电产生的Cu（I）用于催化叠氮化物-炔环加成，在点击化学手柄之间产生新的键。研究活动包括1）使用压电机械还原产生新反应，2）使用压电ATRP生长新聚合物链和类型，3）使用压电反应性交联聚合物凝胶;和4）研究和开发压电响应材料及其机械特性。

Plastics, a form of polymeric materials, break down after repeated use. One of the causes of this break-down is the rupture of chemical bonds of the polymers. Professor Esser-Kahn examines methods of using force or pressure to generate new bonds in plastic materials. These materials will be capable of capturing energy from an applied force or pressure and using it to initiate the growth of a polymer chain or the formation of a polymer network to strengthen the material. This project includes research and educational components to impact fundamental knowledge about polymer materials across the disciplines of chemistry and engineering. Outreach entails summer research training of high-school interns.Jointly supported by the Macromolecular, Supramolecular and Nanochemistry Program of the Division of Chemistry and the Polymer Program of the Division of Materials Research, the Esser-Kahn research group is developing novel approaches that use the reaction of piezo-electric particles as a method to generate new bonds in polymeric materials. In one direction, the project investigates the piezo-reduction of a Cu(II) precursor to a Cu(I) activator that initiates the growth of polymer chain via atom-transfer radical polymerization. In a second direction, the piezo-generated Cu(I) is used to catalyze azide-alkyne cyclo-addition, creating new bonds between click chemistry handles. The research activities include 1) generation of novel reactions using piezo-mechanical reduction, 2) the growth of new polymer chains and types using piezo-ATRP, 3) the crosslinking of polymer gels using piezo-electric reactivity; and 4) the study and development of piezo-responsive materials and their mechanical characterization.