Photochromic Switching for Nanostructured Polymer Gels

在先进制造业中，将材料的形状和排列控制在人类头发厚度的千分之一左右是一项备受追捧的能力。唯一能够控制这些纳米材料的形状和排列的商业仪器价格昂贵(约5000万美元)，而且由于它们需要在平面上使用，速度慢得令人望而却步。一种潜在的变革性替代方法不受这些严格限制的限制，由于缺乏对材料合成所涉及的化学知识的了解而受到阻碍。对这些合成知识的匮乏是通过研究和控制相关化学反应发生的速度来实现的。此外，该项目还教育参与的研究生和本科生掌握最先进的化学技术。K-8年级的学生受到启发，在与家人合作研究主题的同时，考虑在科学和工程领域就业。这个项目的中心目标是对基本的化学动力学有一个基本的了解，以使三维干涉光刻的分辨率超过衍射障碍。关键的要求是一个可逆的、可饱和的反应，并伴随着写材料的步骤。通过控制单体上取代基的空间和电子性质，以及调整其他关键活性成分(例如，聚合物和交联剂)的化学结构来控制反应速度。这项研究的目标包括合成具有系统变化的空间和电子性质的单体衍生物的组合库；量化纳米材料生长的动力学，目的是在低激光强度下获得快速和饱和的平衡；以及大面积聚合无限制的衍射特征。

Controlling the shape and arrangement of materials at sizes roughly a thousandth of the thickness of a human hair is a much sought after capability in advanced manufacturing. The only commercial instrument capable of controlling the shape and arrangement of these nanometer-sized materials is both expensive (~$50 million) and prohibitively slow due to their requirement for use on flat surfaces. A potentially transformative alternate method that is not subject to these severe constraints is hampered by a lack of understanding of the chemistry involved in the synthesis of the materials. The paucity of knowledge on these syntheses is targeted by studying and controlling the speeds at which the relevant chemical reactions occur. Additionally, this project educates participating graduate and undergraduate students in state of the art chemistry techniques. K-8 students are inspired to consider careers in science and engineering while working with their families on research-themed. household material-based activities that are available through a widely accessible online portal.The central aim of this project is to develop a fundamental understanding of the underlying chemical kinetics needed to enable 3-dimensional interference lithography with a resolution beyond the diffraction barrier. The key requirement is a reversible and saturable reaction accompanied by a material-writing step. Reaction rates are controlled by manipulating the steric and electronic nature of substituents on the monomer, and tailoring the chemical structures of the other key active components (e.g., polymers and crosslinking agents). The objectives of this research include the synthesis of a combinatorial library of monomer derivatives with systematically varied steric and electronic properties; quantification of the kinetics of nanometer-sized material growth, with the goal of obtaining rapid and saturable equilibrium under low laser intensities; and polymerization of diffraction unlimited features over large areas.