Mechanically Controlled Polymerization via Piezo-reduction of Copper

塑料是聚合物材料的一种，反复使用后会分解。这种分解的原因之一是聚合物的化学键断裂。Esser-Kahn教授研究了在塑料材料中使用力或压力来产生新键的方法。这些材料将能够从施加的力或压力中捕获能量，并利用它来启动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关于聚合物材料的基础知识。推广活动需要对高中实习生进行暑期研究培训。在化学系高分子、超分子和纳米化学项目和材料研究部聚合物项目的共同支持下，Esser-Kahn研究小组正在开发利用压电粒子的反应作为在聚合物材料中产生新键的方法的新方法。在一个方向上，该项目研究了通过原子转移自由基聚合引发聚合物链生长的铜(I)活化剂的铜(II)前体的压电性还原。在第二个方向上，压电生成的铜(I)被用于催化叠氮-炔环加成，在点击化学手柄之间创建新的键。研究活动包括：1)利用压电机械还原产生新的反应；2)利用压电-ATRP生长新的聚合物链和类型；3)利用压电性进行聚合物凝胶的交联；以及4)研究和开发压电响应材料及其力学特性。

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.