Nanofiltration silica-zirconia membranes

Tsuru, T., Wada, S., Izumi, S., and Asaeda, M. (1998). Preparation of microporous silica-zirconia membranes for nanofiltration. J. Membr. Sci. 149 127-135. 

Porous membranes can be made of polymers (polysulfones, polyacrylonitrile, polypropylene, silicones, perfluoropolymers, polyimides, polyamides, etc.), ceramics (alumina, silica, titania, zirconia, zeolites, etc.) or microporous carbons. Dense organic membranes are commonly used for molecular-scale separations involving gas and vapor mixtures, whereas the mean pore sizes of porous membranes is chosen considering the size of the species to be separated. Current membrane processes include microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), gas and vapor separation (GS), and pervaporation (PV). Figure 1 indicates the types and sizes of species typically separated by these different separation processes. 

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