Netshape Gradient Aerogel Articles Reinforced By Hybrid Molecules and Polymers

本研究弥合了当前技术制造能力与制造柔性、网状梯度二氧化硅气凝胶制品的需求之间的差距。这些多孔凝胶材料的潜在用途包括低温燃料箱的绝缘材料，或用于去除空气中的颗粒或挥发性有机化合物的过滤介质。研究了杂化分子增强气凝胶和聚合物交联保形涂层的基本机理，最终目的是制备密度和孔隙度变化可忽略、疏水性控制强的硅胶气凝胶。这项研究利用了一种新的方法来均匀增强气凝胶，通过化学反应在小的，最佳数量的分子混合，非常小的（大约1纳米）尺寸的有机-无机杂化分子或硅烷末端的聚氨酯与二氧化硅颗粒之间进行。该研究还开发了一种新的“一锅菜”。复杂形状气凝胶制品的制造方法胶凝、化学加固、干燥等步骤均在同一模具中依次进行，大大缩短了制造时间。本研究的结果有望对具有密度、孔隙率和表面能梯度的复杂形状的介孔、网状气凝胶样品的制造产生理解。考虑到在过去十年中对气凝胶研究的大量投资和对气凝胶批处理过程中增强的化学理解的重大发展，这个系统的程序剖析了气凝胶系统的结构和性质产生的来源，将使该领域的广泛科学家和工程师受益。预计其他研究人员将很快开发出几种拟议研究工作的衍生物，以适应来自氧化铝的无机气凝胶或来自聚合物的有机气凝胶。本研究将开展几项外展功能，以吸引少数民族和女性学生接受STEM教育。

This research bridges the gap between manufacturing capability of current technology and the need to manufacture flexible, netshape gradient silica aerogel articles. Potential uses for these porous gel materials include insulation for cryogenic fuel tanks, for example, or filtration media for removal of particulates or volatile organic compounds from air. The fundamental mechanisms of aerogel reinforcement by hybrid molecules and conformal coating of polymer crosslinks are investigated with the ultimate aim to manufacture stronger silica aerogel articles with negligible changes in density and porosity and strong control of hydrophobicity. This research utilizes a novel method for homogeneous reinforcement of aerogels using chemical reactions between small, optimal quantities of molecularly mixed, very small (approximately 1 nanometer) size hybrid organic-inorganic molecules or silane-endcapped polyurethanes with the silica particles. The research also develops a new ?one-pot? manufacturing method for aerogel articles of complicated shapes; the steps of gelation, chemical reinforcement, and drying are all carried out sequentially in the same mold to dramatically reduce the manufacturing time. The results of this research are expected to yield understanding of manufacturing of complex shapes of mesoporous, netshape aerogel specimens with gradients of density, porosity and surface energy. Given the large investment in research on aerogels and significant development of understanding of chemistry of aerogel reinforcement in batch processes over the past decade, this systematic program dissecting the source of structure and property generation in aerogel system will benefit a wide range of scientists and engineers in the field. It is anticipated that several derivatives of the proposed research work will be soon developed by other researchers to accommodate inorganic aerogels derived from alumina or organic aerogels derived from polymeric sources. Several outreach functions will be carried out in this research to attract minority and female students to STEM education.