Continuous Manufacturing of Aerogel-Foam Sheets and Films

这笔赠款将支持研究，为连续制造米长，数十厘米宽的高度多孔的聚合物气凝胶泡沫片材和薄膜提供新知识，从而推进对材料制造的科学理解，并生产使能技术，以服务于国防，健康和能源方面的国家利益。气凝胶-泡沫片材将具有几种长度尺度的共存开孔，其引入了在当前技术中获得的常规泡沫和气凝胶材料无法实现的新功能。 该奖项支持对引入多种长度尺度的开孔的途径以及片材和薄膜的高速制造的研究。新的气凝胶泡沫片材和薄膜将适用于制造防护装备，以防止纳米颗粒和其他生物活性剂侵入人体，作为过滤材料，用于去除10-200 nm尺寸的空气传播纳米颗粒，气溶胶和活生物体，作为油水分离介质，以及作为凝胶电解质隔板，以扩大锂离子电池的温度窗口。在这项研究中开发的知识将有利于几个学科，如纺织，电化学，膜分离，免疫学和制造。研究的多学科性质将扩大代表性不足的群体在研究中的参与，并将对工程教育产生积极影响。 气凝胶-泡沫是将泡沫的某些属性与气凝胶的那些属性结合联合收割机的轻质材料。通过油包油乳液模板法在聚合物气凝胶的固有生成的大孔和中孔网络内引入的微米尺寸孔（大空隙）的群体使这些材料具有吸引力。常规气凝胶制品不含大孔隙，而常规发泡技术不产生气凝胶并且不能适于产生气凝胶泡沫。在这项工作中，将通过油包油乳液模板法结合分步聚合方案，产生聚酰亚胺链在气凝胶结构中引入大孔。在这种情况下，表面活性剂的选择和分散油相对连续相的聚结和凝胶化动力学的相应稳定性提出了几个基本挑战，必须克服这些挑战才能成功制造米长和几十厘米宽的气凝胶泡沫片材和膜样品。嵌段共聚物型非离子表面活性剂的极性，适合于获得稳定的油包油乳液，将影响聚合物凝胶化动力学和大孔皮层的开放性。适当的电子接受能力的有机溶剂将允许凝胶时间从3分钟到3小时的变化。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

This grant will support research that contributes new knowledge on continuous manufacturing of meters long and tens of centimeter wide highly porous, polymer aerogel-foam sheets and films, thus advancing scientific understanding of materials fabrication and producing enabling technologies to serve national interests in defense, health, and energy. The aerogel-foam sheets will have coexisting open pores of several length scales that introduce new functions not achievable from conventional foam and aerogel materials obtained in current technologies. This award supports the research on avenues of introduction of open pores of multiple length scales in conjunction with high-speed fabrication of sheets and films. The new aerogel-foam sheets and films will be appropriate for fabrication of protective gears to combat nanoparticles and other bioactive agent intrusion into human body, as filter materials for removal of 10-200 nm size airborne nanoparticles, aerosols, and living organisms, as oil-water separation media, and as gel electrolyte separators to expand the temperature window of Li-ion batteries. The knowledge developed in this research will benefit several disciplines, such as textiles, electrochemistry, membrane separation, immunology, and manufacturing. The multi-disciplinary nature of the research will broaden participation of underrepresented groups in research and will positively impact engineering education. Aerogel-foams are lightweight materials that combine certain attributes of foams with those of aerogels. A population of micrometer size pores (macrovoids) introduced via oil-in-oil emulsion templating method inside inherently generated macro- and mesoporous networks of polymer aerogels make these materials attractive. Conventional aerogel articles do not contain macrovoids while conventional foaming technologies do not produce aerogels and cannot be adapted to produce aerogel foams. In this work, the macrovoids will be introduced in aerogel architecture via oil-in-oil emulsion-templating method in conjunction with a step-polymerization scheme that produces polyimide chains. In this context, the selection of surfactants and corresponding stability of the dispersed oil phase against coalescence and gelation kinetics of the continuous phase present several fundamental challenges that must be overcome to successfully manufacture meters long and tens of centimeter wide aerogel foam sheets and film specimens. The polarity of block copolymer type non-ionic surfactants, appropriate for obtaining stable oil-in-oil emulsions, will influence the polymer gelation kinetics and the openness of the macrovoid skin layers. The organic solvent of appropriate electron accepting ability will allow variation of gel times from 3 min to 3 h.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.