Formation of Chemically Modified Ceramic Membranes and TheirTransport Characterization

本项目研究化学改性陶瓷膜 气相沉积技术 氧化铝前驱体材料 来自Alcoa的是不对称的，具有α-氧化铝载体和 5 μ m γ-氧化铝表层。 它们的最小孔隙尺寸 (40>）使得它们不适合精细分子筛 分离小分子。 一系列氟化 硅烷用于提供精确控制的 皮肤层的裂缝状毛孔的大小。 的 提出了孔改性过程的机理， 它的可复制性在精心设计的 实验 研究的重点是测量和 这些基本传输特性的建模 模型材料 这些材料的详细形态 被气态和液态系统探测。 这些数据提供 新的见解，并允许测试理论分析 孔隙尺寸接近的介质中的传输现象 分子尺寸 新的陶瓷膜应该能找到 气体混合物分离的新应用。

This project studies ceramic membranes modified by a chemical vapor deposition technique. The alumina precursor materials from Alcoa are asymmetric, with an alpha-alumina support and a 5 >m gamma-alumina skin layer. Their minimum pore dimension (40 >) makes them inappropriate for fine molecular-sieving separations of small molecules. A series of fluorinated silanes are used to provide precisely controlled decreases in the sizes of the slit-shaped pores of the skin layer. The proposed mechanism by which the pore modification process occurs and its reproducibilty are tested in carefully designed experiments. Studies are focused on the measurement and modeling of the fundamental transport properties of these model materials. The detailed morphology of these materials are probed by gaseous and liquid systems. The data provide new insights and allow testing theories for analyzing transport phenomena in media with pore sizes approaching molecular dimensions. The new ceramic membranes should find new applications in separations of gaseous mixtures.