Ultrafiltration titania membranes

Since then, other colloidal oxide systems have been investigated in order to prepare ceramic mesoporous membranes designed for ultrafiltration. The preparation of an electronically conductive membrane from a Ru02 Ti02 mixed oxides sol and the application to an electro-ultrafiltration process [25,26], as well as the preparation of titania and zirconia ultrafiltration membranes [27], have been described following a colloidal process in which a partial destabilization of a metal oxide colloidal suspension is used to produce top layers with different pore size and pore volume in the mesoporous range. In agreement... 

This ligand then acts as a functionality locker when substoichiometric hydrolysis ratios are used. A ratio acacH/M greater than 1 prevents precipitation and leads to stable colloids or gels. Consequently, with a good formulation choice, sols can be prepared in air without precipitation. Either titania or zirconia ultrafiltration layers have been used as supports for these membranes. Figure 17 is a cross-sectional image of a zirconia microporous membrane that is 0.2 jum thick. 

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. 

Alem A, Sarpoolaky H and Keshmiri M (2009), Titania ultrafiltration membrane Preparation, characterization and photocatalytic activity , J Eur Ceram Soc, 29, 629-635. 

Djafer L, Ayral A and Ouagued A (2010), Robust synthesis and performance of a titania-based ultrafiltration membrane with photocatalytic properties , Sep PurifTechnol, 75,198-203. 

Alem, A., Sarpoolaky, H., and Keshmiri, M. (2008) Titania ultrafiltration membrane preparation, characterization and photocatalytic activity. J. Ear. Ceram. Soc., 29, 629 35. 

Larbot A., Fabre J.-P, Guizard C., Cot L., Gillot J. New inorganic ultrafiltration membranes titania and zirconia membranes. J. Am. Ceram. Soc. 1989 72 257-261 Lee B., Zhang J. Preparation, structure evolution and dielectric properties ofBaTiOs thin films and powders by an aqueous sol-gel process. Thin Solid Films 2001 388 107-113 Lee D.-S., Liu T.-K. Preparation ofTi02 sol using TiC as a precursor. J. Sol-Gel Sci. Technol. 2002 25 121-136... 

A. Razmjou, J. Mansouri, V. Chen, M. Lim, and R. Amal, Titania nanocomposite poly-ethersulfone ultrafiltration membranes fabricated using a low temperature hydrothermal coating process. Journal of Membrane Science 380 (2011) 98-113. 

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