Micropatterned polymer-derived ceramic catalysts and sensors

聚合物衍生陶瓷(PDC)是近四十年来得到广泛研究的材料。他们描述了一种新的陶瓷类型，这种陶瓷可以在没有任何添加剂的情况下，通过在惰性或反应性气氛中对适当的前驱体进行热处理来制备。由于前驱体是聚合物性质的，它们可以受到各种不同的成形技术的影响，以制造整体、涂层、纤维、多孔部件以及微型部件。PDCs具有优异的性能，如氧化和腐蚀稳定性，以及在非常高的温度下的结晶和抗蠕变性能。它们还具有有趣和耐人寻味的功能特性，如光学特性、可调电学特性以及催化和光催化活性。在本提案中，将对聚合物衍生陶瓷纳米复合材料用作催化和传感设备中的微型元件的可行性进行基础研究。第一个主要目标将是选择具有催化和传感性能的聚合物衍生陶瓷系统(即，SiOC/MOX、SiCN/M(N)和SiCN/MSix；M=过渡金属)，并评估它们在光刻微图形方面的加工性。对选定的聚合物前驱体进行光刻，然后进行交联化和陶瓷化，将用于生成具有定制性能轮廓的陶瓷微部件。将在本提案框架内讨论的第二个目标涉及将目标陶瓷微部件集成在用于催化和传感目的的微型设备内。因此，三种模型微器件被定义为主要的目标：微结构催化阵列、颗粒和化学电阻。将在本提案中开发的加工技术将为在高温和恶劣环境条件下操作的MEMS类型的器件提供一种方便/新颖的途径。

Polymer-derived ceramics (PDCs) are materials which have been intensively studied in the last four decades. They describe a new class of ceramics which can be prepared without any additives by thermal handling of appropriate precursors in inert or reactive atmosphere. Since the precursors are of polymeric nature, they can be subjected to a large variety of different shaping techniques to fabricate monoliths, coatings, fibers, porous parts as well as micro parts. PDCs present exceptional properties such as oxidation and corrosion stability as well as crystallization and creep resistance up to very high temperatures. They have been also shown to possess interesting and intriguing functional properties such as optical properties, tunable electrical properties, as well as catalytic and photocatalytic activity.Within the present proposal, a fundamental study on the feasibility of polymer-derived ceramic nanocomposites to be used as micro components in devices for catalytic and sensing applications will be performed. The first main goal will be to select polymer-derived ceramic systems with catalytic and sensing properties (i.e., SiOC/MOx, SiCN/M(N), and SiCN/MSix; M = transition metal) and to assess their processability with respect to photolithographic micropatterning. Photolithography of selected polymeric precursors followed by cross-linking and ceramization will be used to generate ceramic microcomponents with tailored properties profile. A second aim which will be addressed in the frame of the present proposal is related to the integration of the target ceramic microcomponents within micro devices for catalytic and sensing purposes. Thus, three model micro devices have been defined as primary target: microstructured catalytic arrays, pellistors, and chemiresistors. The processing technology which will be developed within the present proposal will provide a facile/novel access to MEMS-type devices to be operated at high temperatures and in harsh environmental conditions.