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Indexed by:期刊论文
Date of Publication:2012-02-15
Journal:JOURNAL OF MEMBRANE SCIENCE
Included Journals:SCIE、EI、Scopus
Volume:390
Page Number:175-181
ISSN No.:0376-7388
Key Words:Silylated MCM-48 membrane; Adsorption amount; Pervaporation; Separation factor
Abstract:The MCM-48 type materials and membranes had been successfully silylated with different alkyl chains (methyl, propyl and n-octyl). The silylated MCM-48 membranes prepared on supports with pore size of 1 mu m had a good effect on separation of the ethyl acetate (EA)/water mixture. The materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), IR spectroscopy, pervaporation. These results showed that the silylated MCM-48 type materials could adsorb large amount of EA, about 145 mg/g for C8H17-MCM-48 at 7 kPa at the room temperature, which was ten times of the Si-MCM-48'. Besides this, the C8H17-MCM-48 membranes had EA/H2O separation factor of 251 at room temperature and 123 at 50 degrees C with the total flux 4.3 and 6.6 kg/(m(2) h), respectively. The long-chain alkyl groups grafted in the membrane pore could enhance temperature tolerance of the membrane for separating EA/H2O. Under the same conditions, the CH3- and C3H7-MCM-48 membranes had lower separation factor and larger total flux. The phenomenon in the separation experiments was controlled by the solution-diffusion mechanism. EA molecules were firstly adsorbed in the silylated pores selectively and made up a compact hydrophobic membrane, which could prevent the penetration of the water, resulting in the high EA selectivity. (C) 2011 Elsevier B. V. All rights reserved.