Preparation and characterization of ZSM-5 zeolite incorporated chitosan membrane

Bingbing LIU; Yiming CAO; Quan YUAN

ABSTRACT

BACKGROUND:

The incorporating of zeolites or porous fillers into polymer membranes can improve the pervaporation separation properties of membranes.But the effect mechanism of zeolites or porous fillers on membrane properties needs to be further studied.

OBJECTIVE:

The study was designed to prepare ZSM-5 zeolite incorporated chitosan membrane by solution blending method to investigate the effecIs of zeolite on membrane pervaporation properties.

DESIGN:

A controlled observation.

SETTING:

Dalian Institute of Chemical Physics,Chinese Academy of Sciences.MATERIALSThis study was performed at the Laboratory of New Type Membrane Separation Technology,Dalian Institute of Chemical Physics,Chinese Academy of Sciences in May 2006.Chitosan,with deacetylation degree of 75%-85%,was obtained from Sigma-Aldrich Chemical Company,USA;Dimethyl carbonate(DMC),with purity of 99%,was purchased from Fluka Chemical Company,USAZSM-5 zeolite was kindly supplied by Dalian Institute of Chemical Physics,Chinese Academy of Sciences,China;Methanol,with purity＞99.5%,were purchased from Shenyang Lianbang Chemical Company,China.

METHODS:

ZSM-5 zeolite incorporated chitosan membranes were prepared by solution blending method.MAIN OUTCOME

MEASURES:

①Swelling and sorption of ZSM-5 zeolite-incorporated chitosan membranes in the DMC/methanol mixture.②Effects of zeolite content in the membrane and operating temperature on pervaporation properties.

RESULTS:

Scanning electron mieroscope demonstrated that zeolite was uniformly distributed in the membrane matrix and the membranes were free from possible defects.The separation selectivity of dimethyl carbonate(DMC)/methanol mixtures was dominated by solubility selectivity rathcr than diffusivity selectivity.Swelling degree increased and the permeation flux of the membranes increased significantly with the zeolite content increasing.From the temperature-dependent permcation values,the Arrhenius activation parameten were estimated.

CONCLUSION:

The pervaporation results indicated that the membranes incorporated with the ZSM-5 zeolite exhibited better separation properties for DMC/methanol mixtures comparing with homogeneous chitosan membranes.