CAREER: Control of Self-Assembly and Electrostatics with Photolabile Polymers

目前在制备和利用光响应部分方面的限制已经抑制了以新方式利用光响应聚合物的优点的使能技术的发展。 该奖项的研究目标是开发具有新的光响应特性的聚合物材料，因为它包含了光不稳定基团，如邻硝基苄基酯（NBE）部分。 本研究的中心假设是，合理设计的聚合物与光不稳定基团将使光化学控制的非共价分子间的疏水性和电荷-电荷相互作用的力量。 这项研究将集中在三类新的光响应聚合物系统：1）新的嵌段共聚物，旨在从疏水性切换到亲水性，2）层-层（LbL）的可吸收薄膜，切换层间静电力从吸引到排斥，和3）表面结合的聚合物涂层，切换zeta电位的符号。 这项工作意义重大，因为它结合了聚合物合成和光化学来控制分子间的作用力，从而产生了用光控制物质的新方法。 这项研究的预期成果包括光组装成胶束和从胶束中拆卸的聚合物，在三维中可图案化的LbL膜，以及能够对电渗透流体流动和静电荷进行光化学控制的涂层。 这些结果在以下方面具有潜在的应用：1）用于靶向递送的光化学不稳定载体，2）全水性光刻，3）光控微流体装置，以及4）绝缘体静电荷的光化学控制。 对光有反应的材料具有重大的技术重要性，其应用范围从人类健康（例如成像剂和治疗剂的光化学递送）到微处理器制造（例如光刻中聚合物的高分辨率图案化）。 拟议的跨学科研究将开发聚合物，以新的方式对光作出反应，具有基础和应用意义。 拟议的工作还通过两个新项目将这项研究与教育结合起来：1）通过让当地社区学院参与科学研究来鼓励STEM职业; 2）高中科学博览会指导计划。

TECHNICAL SUMMARYCurrent limitations in the preparation and utilization of photoresponsive moieties have inhibited the development of enabling technologies that use the advantages of light-responsive polymers in new ways. The research objective of this award is to develop polymeric materials that have new photoresponsive properties because of the inclusion of photolabile groups, such as the o-nitrobenzylester (NBE) moiety. The central hypothesis of this research is that rational design of polymers with photolabile groups will enable photochemical control over the non-covalent intermolecular forces governed by hydrophobicity and charge-charge interactions. This research will focus on three classes of new light-responsive polymeric systems: 1) new block copolymers designed to switch from hydrophobic to hydrophilic, 2) layer-by-layer (LbL) polyelectrolyte films that switch interlayer electrostatic forces from attractive to repulsive, and 3) surface-bound polymeric coatings that switch the sign of the zeta potential. The proposed work is significant because it combines polymer synthesis and photochemistry to control intermolecular forces, resulting in new approaches to control matter with light. Expected outcomes of this research include polymers that photo-assemble into and disassemble from micelles, LbL films that are photopatternable in three dimensions, and coatings that enable photochemical control over electroosmotic fluid flow and static charging. These outcomes have potential applications in: 1) photochemically-labile carriers for targeted delivery, 2) all-aqueous photolithography, 3) photo-controlled microfluidic devices, and 4) photochemical control over the static charging of insulators. NON-TECHNICAL SUMMARYMaterials that respond to light have major technological importance, with applications ranging from human health (e.g. imaging agents and photochemical delivery of therapeutic agents) to microprocessor fabrication (e.g. high-resolution patterning of polymers in photolithography). The proposed interdisciplinary research will develop polymers that respond to light in new ways with both fundamental and applied implications. The proposed work also integrates this research with education through two new programs: 1) encouraging STEM careers by involving a local community college in scientific research; 2) a high school science fair mentoring program.