Collaborative Research: Understanding UV Protective Mechanisms Using Hybrid Nanoarchitectures

CBET-0756600三径建议的中心假设是，生物衍生的活性物种与保护性纳米结构的不同组件之间在不同长度尺度上的相互作用可以显著提高活性物种对紫外线照射和氧气的稳定性。必须探索新的杂化结构，包括合成聚合物、纳米颗粒和天然染料或DNA，以实现可调的功能特性，并在分子重新定向、光化学和扩散过程的距离和时间尺度的背景下，阐明保护剂分子(紫外线吸收剂和紫外线稳定剂)的空间分布与稳定效率之间的关系。虽然封装技术可能已经显示出紫外线敏感材料的热稳定性和光氧化稳定性的增加，但由于增益很小，它们在实际应用中的应用还不存在。在这里，我们提出了一种新的设计防护材料的范例。为了实现这一目标，我们建议开发三种新型的防护材料结构。此外，我们提出了一种协同的方法，通过结合实验和建模来利用所有四种PI的优点来清楚地理解聚合物包覆提高紫外线(UV)敏感材料的光稳定性的机理。智力价值：该计划的智力价值体现在该项目的目标中，包括：(1)开发具有可调保护性能的核壳微球，包括壳层组成、厚度和纳米胶囊的程度。设计了一套新的模块化纳米结构，突出了保护剂分子的空间排列，可以系统地改变，以及可以监测的缓蚀效率。(2)开发一种受控的微流控制造方法，其中紫外线吸收剂被集成到壳体中。(3)用于精确生产包裹两种互补活性物质：紫外线敏感物种和紫外线吸收物质的独特纳米结构的新合成路线。(4)发展传输和分子模拟来分析实验结果，并预测光稳定剂组合的稳定性的空间相关性。合成路线的发展和有效紫外线防护关键性质的鉴定将有助于阐明从分子尺度到微米尺度的不同长度尺度上紫外线防护相互作用的相互作用。这项研究可以指导多功能防护材料在敏感设备的紫外线防护、紫外线敏感剂(如生物传感试剂)的储存和运输系统等领域的未来光化学和环境技术的发展，从而通过保留分子结构和功能来延长生物和化学去污和防护技术的使用寿命。这项研究的目的是了解如何同时获得几个与传统材料相比的有利设计性能，如防紫外线透明、控制氧气渗透、提高热稳定性和机械完整性。拟议的合作计划整合了几个机构的外展计划，计划将实验方法和研究成果用作研究生、本科生和高中生的强大教育工具。我们建议为高中生和本科生开发一个教育项目，展示反应加工、纳米技术、聚合物科学和微流体的关键特征，目的是提高和保持他们对科学和工程的兴趣。此外，我们将把这项研究整合成一门为期一学期的课程，以及为研究生和来自当地行业的参与者开设的一门短期课程。该项目将利用来自哥伦比亚大学、布朗大学、马萨诸塞大学达特茅斯分校和美国陆军纳蒂克研究中心的化学家和化学工程师的研究专长。

CBET-0756600TripathiThe central hypothesis of the proposal is that the interactions, at different length scales, between a bioderived active species and various components of a protective nanoarchitecture can lead to significantly increased stability of the active species to UV exposure and oxygen. New hybrid architectures, incorporating synthetic polymers, nanoparticles, and natural dyes or DNA, must be explored to achieve tunable functional properties and to elucidate the relationship between the spatial distribution of protectant molecules (UV absorbers and UV stabilizers) and stabilization efficiency, in the context of the distance and time scales of molecular reorientation and photochemical and diffusive processes. While encapsulation techniques may have shown increases in the thermal and photo-oxidative stability of a UV sensitive material, their use in practical applications is nonexistent due to small gains. Here, we propose a new paradigm for designing protectant materials. To accomplish this objective, we propose development of three novel architectures for protectant materials. Furthermore, we propose a synergistic approach that leverages the strengths of all four PI's by combining experiments and modeling to develop a clear understanding of the mechanism by which polymeric encapsulation improves the photostability of ultraviolet (UV) sensitive materials. Intellectual Merit: The intellectual merit of the program is manifested in the goals of the project that include: (1) Development of core-shell microspheres with tunable protection properties including shell composition and thickness and degree of nanoencapsulation. The design of a new set of modular nanoarchitectures highlights the spatial arrangement of protectant molecules which can be systematically varied and the inhibition efficiency which can be monitored. (2) Development of a controlled microfluidic fabrication method where UV absorbers are integrated into the shell. (3) Novel synthesis routes for the precise production of unique nanoarchitectures encapsulating two complementary active agents: UV sensitive species and UV absorbing substances. (4) Development of transport and molecular modeling to analyze experimental results and to predict the spatial dependence of stabilization for combinations of photostabilizers. The development of synthesis routes and identification of the critical properties for efficient UV protection will help to clarify the interplay of UV protective interactions at various length scales, ranging from the molecular scale to the microscale. This research can guide the development of multifunctional protective materials into future photochemical and environmental technology in the areas of UV protection of sensitive equipment, storage and transport systems for UV sensitive reagents (e.g. biosensing reagents), thereby extending the operational life time of biological and chemical decontamination and protection technologies by preserving molecular structure and therefore function. The research is aimed at understanding how to obtain several advantageous design properties simultaneously, compared with conventional materials, such as transparency with UV-protection, control of oxygen permeation, increased thermal stability, & mechanical integrity. Integrating the outreach programs of several institutions, the proposed collaboration plans to use the experimental methods and outcomes of research as powerful educational tools for graduate, undergraduate and high school students. We propose to develop an educational program that demonstrates key features of reactive processing, nanotechnology, polymer science, and microfluidics for high school and undergraduate students, with the goal of raising and maintaining their interest in science and engineering. Also, we will integrate this research into a semester-long course and a short course for graduate students and participants from local industries. The project will utilize the research expertise of chemists and chemical engineers from Columbia University, Brown University, the University of Massachusetts at Dartmouth, and the U.S. Army Natick Research Center.