Poly zeolite-filled

Yang, H., Nguyen, Q.T., Ping, Z., Long, Y. and Hirata, Y. 2001. Desorption and pervaporation properties of zeolite-filled poly(dimethylsiloxane) membranes. MMer es JnmvM. 5 101-106. 

The template-assisted synthetic strategies outlined above produce micro- or mesoporous stmetures in which amorphous or crystalline polymers can form around the organic template ligands (174). Another approach is the use of restricted spaces (eg, pores of membranes, cavities in zeolites, etc.) which direct the formation of functional nanomaterials within thek cavities, resulting in the production of ultrasmaU particles (or dots) and one-dimensional stmetures (or wkes) (178). For example, in the case of polypyrrole and poly(3-methylthiophene), a solution of monomer is separated from a ferric salt polymerization agent by a Nucleopore membrane (linear cylindrical pores with diameter as small as 30 nm) (179—181). Nascent polymer chains adsorb on the pore walls, yielding a thin polymer film which thickens with time to eventually yield a completely filled pore. De-encapsulation by dissolving the membrane in yields wkes wherein the polymer chains in the narrowest fibrils are preferentially oriented parallel to the cjlinder axes of the fibrils. 

Water can be removed from methanol by a membrane of polyvinyl alcohol cross-linked with polyacrylic acid, with a separation factor of 465.204 A polymeric hydrazone of 2,6-pyridinedialdehyde has been used to dehydrate azeotropes of water with n- and /-propyl alcohol, s- and tort butyl alcohol, and tetrahydrofuran.205 The Clostridium acetobutylicum which is used to produce 1-butanol, is inhibited by it. Pervaporation through a poly(dimethyl-siloxane) membrane filled with cyclodextrins, zeolites, or oleyl alcohol kept the concentration in the broth lower than 1% and removed the inhibition.206 Acetic acid can be dehydrated with separation factors of 807 for poly(4-methyl-l-pentene) grafted with 4-vinylpyridine,207 150 for polyvinyl alcohol cross-linked with glutaraldehyde,208 more than 1300 for a doped polyaniline film (4.1 g/m2h),209 125 for a nylon-polyacrylic acid membrane (5400 g/m2h), and 72 for a polysulfone.210 Pyridine can be dehydrated with a membrane of a copolymer of acrylonitrile and 4-styrenesulfonic acid to give more than 99% pyridine.211 A hydrophobic silicone rubber membrane removes acetone selectively from water. A hydrophilic cross-linked polyvinyl alcohol membrane removes water selectively from acetone. Both are more selective than distillation.212... 

The filling of the distribution column contains a material called carrier, which is coated with a liquid absorbent. Zeolites or glass spheres are usually used as carriers whereas non-volatile liquids such as silicone oil or poly-ethylene glycol are used as the absorbents in distribution columns. 

Zeolites modifled with organic solvents increase the reastance and degree of radiation crosdinking of filled poly-vinyl-chloride. The dehydrochlorination rate of poly-vinyhchloride on y-irradiation decreases in the presence of zeolites due to the sorption of hydrochloric acid by the filler. Modification of zeolite with carbcMi tetrachloride and methjlene chloride decrease the swelling d ee of filled poly-vinyl-chloride also. 

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