CAREER: Photodirected Assembly of Custom-Designed Polyelectrolyte Complexes

职业：定制设计的聚电解质复合物的光导组装

• 批准号: 1150908
• 负责人: Yakov Lapitsky
• 金额: $ 40.14万
• 依托单位: University of Toledo
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1150908&HistoricalAwards=false
• 关键词: CAREER; Photodirected; Assembly; Custom; Designed

Lapitsky, Yakov1150908 Intellectual Merit: The PI proposes to create stimulus-responsive interfacial microstructures and microdevices through the photodirected assembly of polyelectrolytes. Recent advances in chemical product design, medicine and nanotechnology have ushered in a new age of ?smart? materials that respond to external stimuli such as changes in pH, ionic strength, temperature, and mechanical or electromagnetic perturbations. Stimulus-responsive polyelectrolyte complexes are routinely used as building blocks for these materials and find countless applications, ranging from controlled release of bioactive payloads, to self-healing materials and soft microelectromechanical systems (MEMS), to energy devices and water purification. These technologies require custom-designed structures with an assortment of well-defined morphologies. Yet, methods for the microfabrication of polyelectrolyte complexes remain limited to simplistic structural motifs (e.g., planar, spherical, cylindrical, and prism-like or pyramid-like). This severely limits both the range and intricacy of the supramolecular architectures that can be prepared from polyelectrolytes, and presents a major obstacle in the 3-D assembly of polyelectrolyte-based microdevices. To address this, the PI aims to direct the assembly of intricate polyelectrolyte structures via 3-D photopatterning of polyelectrolyte solutions, where one of the polymer species only becomes charged when exposed to light. The PI hypothesizes that the irradiation at the focal point of the multiphoton laser will induce rapid and localized polyelectrolyte self-assembly into colloidal materials, whose shapes and dimensions will be directed by the beam path. This project has three objectives: (1) investigating photodirected assembly of polyelectrolytes as a method for preparing intricate supramolecular structures, (2) dissecting the photodirected assembly process with the view of developing robust guidelines for controlling materials interfacial structure and stimulus sensitivity, and (3) exploiting the stimulus-responsive properties of photopatterned polyelectrolyte complexes to prepare micron-scale controlled release devices, actuators and materials that self-destruct. This research leverages the PI?s background in polyelectrolyte self-assembly, and will dramatically expand the range and intricacy of polyelectrolyte-based materials that can be prepared for customized controlled release, sensor and actuator technologies.Broader Impacts: This work will advance the design and microfabrication of smart devices for medical, environmental and household applications. Likewise, the ability to produce novel stimulus-responsive structures has the potential to accelerate the development of advanced membranes, coatings, electronics and energy devices. Importantly, this research will be closely integrated with educational outreach. The PI will introduce high school students to stimulus-responsive polyelectrolytes in the Engineer for a Day and EXCEL programs that are offered to Toledo Public Schools. Moreover, he will continue his involvement in the Engineering for Teachers of Migrant Students (ETMS) distance learning course. ETMS provides graduate training for teachers in rural communities who teach children of migrant farm workers, and aims to develop a set of experiments that demonstrate the importance of mathematics, science and engineering to everyday life. The PI has recently become involved with ETMS, and has already developed several demonstrations that use stimulus-responsive polymers found in household products (e.g., alginate, poly(acrylic acid), and methylcellulose) to reinforce concepts that are learned in high school chemistry. To disseminate the ETMS materials more broadly, step-by-step tutorials will be posted on the PI?s website and on YouTube. These outreach activities will help increase and diversify the enrollment of science and engineering students. Furthermore, the PI?s research will train undergraduate and graduate students (including women and underrepresented minorities) in the use of materials characterization techniques, and in the fundamentals of colloid and polymer science. This research will also generate stimulating examples and project topics, which the PI will incorporate into the colloids and transport phenomena courses that he will teach at the University of Toledo.

智力优势：PI提议通过聚电解质的光导组装创建刺激响应界面微结构和微器件。化学产品设计、医学和纳米技术的最新进展引领了一个“智能”的新时代。对外界刺激有反应的材料，如pH值、离子强度、温度、机械或电磁扰动的变化。刺激响应型多电解质复合物通常被用作这些材料的构建模块，并找到了无数的应用，从生物活性有效载荷的控制释放，到自修复材料和软微机电系统（MEMS），再到能源设备和水净化。这些技术需要定制设计的结构和各种定义良好的形态。然而，微加工多电解质复合物的方法仍然局限于简单的结构基元（例如，平面、球形、圆柱形和棱柱状或金字塔状）。这严重限制了聚电解质制备的超分子结构的范围和复杂性，并对基于聚电解质的微器件的三维组装构成了主要障碍。为了解决这个问题，PI的目标是通过聚电解质溶液的三维光模式来指导复杂的聚电解质结构的组装，其中一种聚合物只有在暴露于光下才会带电。PI假设在多光子激光的焦点处照射将诱导聚电解质快速和局部自组装成胶体材料，其形状和尺寸将由光束路径引导。这个项目有三个目标：(1)研究聚电解质的光导组装作为制备复杂超分子结构的方法；(2)从制定控制材料界面结构和刺激敏感性的鲁棒指南的角度分析光导组装过程；(3)利用光模式聚电解质复合物的刺激响应特性来制备微米尺度的可控释放装置、致动器和自毁材料。这项研究利用了PI？在聚电解质自组装方面的背景，并将大大扩大聚电解质基材料的范围和复杂性，这些材料可用于定制控制释放，传感器和执行器技术。更广泛的影响：这项工作将推动医疗、环境和家庭应用智能设备的设计和微制造。同样，生产新型刺激响应结构的能力有可能加速先进膜、涂层、电子和能源设备的发展。重要的是，这项研究将与教育推广紧密结合。PI将在托莱多公立学校提供的“一天工程师”和EXCEL项目中向高中生介绍刺激反应性聚电解质。此外，他将继续参与农民工教师工程（ETMS）远程学习课程。ETMS为农村社区教授农民工子女的教师提供研究生培训，并旨在开发一套实验，证明数学、科学和工程对日常生活的重要性。PI最近参与了ETMS，并且已经开发了几个演示，使用在家用产品中发现的刺激响应聚合物（例如海藻酸盐，聚（丙烯酸）和甲基纤维素）来强化高中化学学习的概念。为了更广泛地传播ETMS材料，将在PI？在美国的网站和YouTube上。这些外展活动将有助于增加理工科学生的入学人数并使其多样化。此外，PI？美国的研究将训练本科生和研究生（包括女性和代表性不足的少数民族）使用材料表征技术，以及胶体和聚合物科学的基础知识。这项研究还将产生令人兴奋的例子和项目主题，PI将把它们纳入他将在托莱多大学教授的胶体和运输现象课程中。