Inorganic-organic polymers phosphonic acid

Li, S., Zhou, Z., Abernathy, H., Liu, M., Li, W, Ukai, J., Hase, K. and Nakanishii, M. 2006. Synthesis and properties of phosphonic acid-grafted hybrid inorganic-organic polymer membranes. Journal of Materials Chemistry 16 858-864. 

Umeda, J Suzuki, M Kato, M Moriya, M. Sakamoto, W. Yogo, T. (2010). Proton conductive inorganic-organic hybrid membranes functionalized with phosphonic acid for polymer electrolyte fuel cell. /. Power Sources, 195, 5882-5888, ISSN 0378-7753. 

Tetravalent metal phosphonates (MELS ) are layered compounds that can be considered organic/inorganic polymers. The organic functionality provided by the phosphonate largely determines the surface chemistry of these materials. Choosing phosphonates with an arylsulfonic acid function produces materials that are effective as acid catalysts. This paper describes synthetic procedures used to prepare arylsulfonic acid MELS and methods to increase and stabilize their surface area, porosity, and swelling properties. Acid catalysis by MELS is exemplified by the synthesis of methyl tertiary butyl ether. 

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