CAREER: Hybrid Material Routes to Porous Amorphous Ceramics with Controlled Microstructure

摘要CTS-9624841这项研究的目标是开发制备多孔块状凝胶或薄膜形式的硅基陶瓷的方法，这些薄膜具有明确的多孔形貌和孔化学成分。这项工作开发了溶胶-凝胶法合成有机/无机杂化材料，通过热解或溶剂萃取将杂化材料中的有机成分全部或部分去除，即可转化为多孔陶瓷。杂化材料中的有机成分既可以作为二氧化硅陶瓷网络中分子分散的固体溶质，也可以作为相分离的介观或宏观结构域形成，并分别用作微孔陶瓷或介孔和大孔陶瓷的前驱体。还开发了从杂化材料中选择性地去除非共价键合有机聚合物并将共价键合有机配体留在多孔二氧化硅网络上的方法。这些分子模板法被用来产生具有几个特定目标的明确的多孔膜：可聚合有机配体(例如，通过自由基、离子或消除机制)被并入作为分子模板，用于产生具有高度孔连接性和取向度的多孔膜；金属螯合有机模板与特定的金属或金属离子一起被结合在杂化薄膜的合成中，用于形成表现出高热稳定性、选择性传输特性和/或催化活性的多孔陶瓷膜；将表现出特定分子识别特性的有机配体结合到杂化材料中，使得在由它们形成多孔薄膜之后，有机配体优先定位在多孔网的表面上，因此可以用于开发用于化学传感应用的多孔性基质。教育发展包括修订和改进本科生和研究生化学工程课程的具体方面，包括为化学工程领域的高危本科生建立个别化教学计划，建立本科生研究计划，特别是针对未被充分代表的民族的学生，以及发展跨学科、工业和联邦(国家实验室)合作，使学生接触到化学、材料科学和微制造领域的各个方面。这一教育计划的一个主要组成部分是实施一项本科生研究方案，其主要目标是为来自代表性不足群体的学生进入研究生院做好准备。这是与新墨西哥大学已经实施的几个少数族裔教育项目合作完成的，这些项目旨在加强少数族裔学生，特别是新墨西哥州相对较大的拉美裔和美洲原住民社区的成员获得研究职业的机会。

ABSTRACT CTS-9624841 The goal of this research is to develop methods of generating silica-based ceramics in the form of porous bulk gels or as thin membrane films that have well-defined porous morphologies and pore chemistries. This work develops sol-gel routes to the synthesis of hybrid organic/inorganic materials that can be converted to porous ceramics by the total or partial removal of the organic component of the hybrid materials through pyrolysis or solvent extraction. Hybrid materials incorporate organic constituents either as molecularly well-dispersed solid solutes in the silica- ceramic network or as phase-segregated mesoscopic or macroscopic domains are formed and used as precursors to microporous ceramics or to mesoporous and macroporous ceramics, respectively. Methods that selectively remove non-covalently bonded organic polymers from hybrid the materials and leave covalently bonded organic ligands on the porous silica networks are also developed. These molecular templating approaches are used to generate well-defined porous films with several specific goals: polymerizable organic ligands (e.g., through free radical, ionic, or elimination mechanisms) are incorporated as molecular, templates for the generation of porous thin films that exhibit high degrees of pore connectivity and orientation; metal-chelating organic templates are incorporated, together with particular metals or metal ions, in the synthesis of hybrid thin films that are used to form porous ceramic membranes that exhibit high thermal stability, selective transport characteristics, and/or catalytic activity; organic ligands exhibiting specific molecular recognition properties are incorporated into hybrid materials such that, after a porous thin film is formed from them, the organic ligands are localized preferentially on the surface of the porous network and hence can be used in the development of porous matrices for chemical sensing applications. Education developments include the revision an d improvement of specific aspects of the undergraduate and graduate chemical engineering curricula, including the establishment of an individualized instruction program for at-risk undergraduate students in chemical engineering the establishment of undergraduate research programs, especially for students from underrepresented ethnic groups, and the development of cross-disciplinary, industrial and federal (National Laboratory) collaborations that will expose students to aspects of the fields of chemistry, materials science, and microfabrication. A major component of this educational plan is the implementation of an undergraduate research program whose main goal is the preparation of students from underrepresented groups for entry into graduate school. This is done in cooperation with several minority educational programs already in place at the University of New Mexico to enhance the access of minority students, especially members of New Mexico's relatively large Hispanic and Native American communities, to research careers.