![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
Abstract
Inorganic composite membranes were manufactured by partial zeolitisation of polymer derived ceramic (PDC) tapes. The PDC tapes, which act as mechanical support and chemical source for the zeolite framework builder at the same time, were prepared by tape casting with a slurry composed of polysiloxanes as preceramic polymers, inert (SiC) and reactive (elemental Si) filler particles, and subsequent pyrolysis in argon or nitrogen atmosphere. The tape porosity and the amount of silicon after pyrolysis, available for zeolite crystallisation were controlled by pyrolysis atmosphere and temperature. The partial transformation of the metallic silicon, contained in the tapes, into zeolite crystals was carried out by hydrothermal treatment of the tapes in an aqueous, alkaline solution containing a so called structure directing agent at 150°C with reaction time between 24 and 96 h. The PDC tapes, the PDC tape/zeolite composites and the influence of the thermal history and pyrolysis atmosphere of the PDC tapes on the zeolite layer properties were characterised by means of solid state characterisation, porometry and chemical analysis. With complementary results from the liquid phase after crystallisation (the so called mother liquor) the main parameters affecting the amount and morphology of the zeolite layers on the PDC foams were identified.