ISS: Synthesis of Electrically Conductive High-Temperature Composites Under Microgravity and Normal Gravity Conditions

随着空间探索的快速推进，在空间进行材料研究正成为主流。与此同时，新型二维材料和聚合物衍生高温陶瓷引起了材料界的关注。在这项研究项目中，二维MXene将被并入氧化碳化硅基质中，以在地球和国际空间站产生新材料。将二维材料在微重力条件下的高温演化行为和聚合物向陶瓷的转化与地球上的过程进行系统的比较。这些材料有望具有高抗氧化性、良好的导电性和低密度。它们还应该在韧性、强度和高温稳定性方面具有很大的协同潜力。这种复合材料可以根据应用需求制成几乎任何形状(块状、涂层、离散特征等)和尺寸(纳米到宏观)。此外，这些材料可以很容易地生产复杂形状、薄壁或自由形状的部件，具有在高温环境下的轻量化和功能性。这项研究将带来新一代先进材料，这些材料具有巨大的潜力，可用于换热器、电气系统、催化剂载体、储能、电极、纳米器件和微系统。最终，项目成果将带来新的应用，造福于空间科学和地球生命。研究生和本科生都将参与这个研究项目。PI将把目前的活动扩展到弗吉尼亚州东部，同时继续努力在校园内举办不同的夏令营。此外，PI将把推广工作扩展到西弗吉尼亚科学博物馆，以激发女性和少数族裔对科学和工程的兴趣。这项研究项目将促进对不同引力条件下原子和纳米级物种相互作用的了解，以探索一类新的高温稳定和导电材料。高温复合材料将包括致密和多孔的微结构，但所开发的方法将适用于由2D添加剂和聚合物前驱体衍生的广泛的高温材料。本研究有望为聚合物衍生陶瓷的原子能级设计和热力学预测提供新的理论、知识和方法。该项目的成果将为利用微重力了解和创造新型高温材料开辟新的机会。该团队将使用四种方法进行研究。首先，利用MXene剥离和表面功能化，将在500-700°C进行预热分解，以便为微重力和地球重力研究提供受控状态。其次，将在地球上和微重力下进行不同的大气热解，以了解大气和气体释放对新相形成的影响。第三，理论热力学计算和实验热解研究相结合，以探索基本的界面相互作用和相演变过程。最后，将全面研究重力对二维MXene在热解过程中的变形、堆积以及与碳化硅的化学作用的影响；不同重力条件下多孔系统的相和结构演变将与孔的稳定性和收缩/坍塌相关。教育部分是培训多个研究生和本科生，重点是妇女和少数群体。PI将把目前的活动扩展到弗吉尼亚州东部，同时继续努力在校园内举办不同的夏令营。此外，PI将把外展工作扩展到西弗吉尼亚科学博物馆，以激发女性和少数族裔对科学和工程的兴趣。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With the fast advancement of space exploration, conducting materials research in space is becoming mainstream. At the same time, novel two-dimensional materials and polymer derived high temperature ceramics have captured the attention of the materials community. In this research project, two dimensional MXene will be incorporated into a silicon oxycarbide matrix to generate new materials, both on Earth and at the International Space Station. The high temperature evolution behaviors of two-dimensional materials and polymer to ceramic conversion under microgravity conditions will be systematically compared with the processes on Earth. These materials are expected to have high oxidation resistance, excellent electrical conductivity, and low density. They should also have great synergistic potentials for toughness, strength, and high temperature stability. The composites can be made into almost any shape (bulk, coating, discrete feature, et cetera) and size (nano- to macro-) based on application needs. In addition, these materials can easily produce complex shape, thin-wall, or freeform components with lightweight and functional capabilities in high temperature environments. This research will usher in a new generation of advanced materials which have great potential to be used as heat exchangers, electric systems, catalyst support, energy storage, electrodes, nano-devices, and microsystems. Ultimately, project results will lead to new applications benefiting space science and life on Earth. Both graduate and undergraduate students will be involved in the research project. The PI will expand current activities to Eastern Virginia while continuing efforts with different summer camps on campus. In addition, the PI will expand outreach efforts to the Western Virginia Science Museum to stimulate the interest of females and minorities in science and engineering.This research project will advance understanding of atomic- and nano-level species interactions under different gravitational conditions in order to explore a new class of high temperature stable and electrically conductive materials. The high temperature composites will include both dense and porous microstructures but the methodology developed will be applicable to a wide range of high temperature materials derived from 2D additives and polymer precursors. This research project is expected to develop new theories, provide new knowledge, and offer novel methods in atomic level design and thermodynamic prediction of polymer derived ceramics. Results from this project will open new opportunities for using microgravity to understand and create novel high temperature materials. The team will conduct the research using four approaches. First, using MXene exfoliation and surface functionalization, pre-pyrolysis at 500-700°C will be conducted in order to provide controlled states for microgravity and Earth gravity studies. Second, different atmosphere pyrolysis will be conducted on Earth and under microgravity to understand the atmosphere and gas release effects on new phase formation. Third, theoretical thermodynamic calculation and experimental pyrolysis studies will be combined in order to explore the fundamental interfacial interaction and phase evolution processes. Finally, gravitational effects on 2D MXene deformation, stacking, and chemical interaction with silicon oxycarbide during pyrolysis will be comprehensively investigated; the phase and structural evolution of the porous systems will be correlated with pore stability and shrinkage/collapse under different gravity conditions. The educational component is training of multiple graduate and undergraduate students, with a focus on women and minorities. The PI will expand current activities to Eastern Virginia while continuing efforts with different summer camps on campus. In addition, the PI will expand outreach efforts to the Western Virginia Science Museum to stimulate the interest of females and minorities in science and engineering.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.