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

技术综述目前在制备和利用光响应性部分方面的限制阻碍了以新的方式利用光响应性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性能的聚合物材料，因为包含了不耐光的基团，如邻硝基苯甲酸酯(NBE)部分。这项研究的中心假设是，合理设计具有光敏基团的聚合物将能够光化学控制由疏水性和电荷相互作用控制的非共价分子间作用力。这项研究将集中在三类新型的光响应聚合物系统：1)设计用于从疏水转换为亲水的新型嵌段共聚物，2)将层间静电力从吸引转换为排斥的逐层(LBL)聚电解质薄膜，以及3)切换Zeta电位符号的表面结合聚合物涂层。这项拟议的工作意义重大，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到胶束中和从胶束中拆分的聚合物，可在三维中光致替代的LBL薄膜，以及能够对电渗透流体流动和静态电荷进行光化学控制的涂层。这些成果在以下方面有潜在的应用：1)用于靶向传递的光化学不稳定载体，2)全水光刻，3)光控微流控器件，4)对绝缘子静电的光化学控制。对光有反应的非技术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输送)到微处理器制造(例如，在光刻中对聚合物进行高分辨率图案化)。拟议的跨学科研究将开发以新的方式对光做出反应的聚合物，具有基础和应用意义。这项拟议的工作还通过两个新计划将这项研究与教育相结合：1)通过让当地社区大学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.