Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
637187 | Journal of Membrane Science | 2009 | 13 Pages |
Abstract
This work presents the fabrication of cellulose acetate (CA)-ceramic composite membranes using dip coating technique. Ceramic supports used in this work were prepared from kaolin with an average pore size of 560Â nm and total porosity of 33%. The dip coating parameters studied experimentally were the concentration of CA solution (varying from 2Â wt% to 8Â wt%) in acetone and dipping time (varying from 30Â s to 150Â s). The fabricated composite membranes were characterized using scanning electron microscope, gas permeation, pure water flux and ultrafiltration (UF) experiments using bovine serum albumin (BSA). It was observed that the membrane prepared with 2Â wt% and 4Â wt% CA were suitable for microfiltration applications and those with 6Â wt% and 8Â wt% were for ultrafiltration applications. Theoretical investigation was conducted to know the macroporous and mesoporous structure of the prepared membranes using Knudsen and viscous permeability analysis of air. A resistance in series model was applied to identify different resistances responsible for the flux decline. Phenomenological models were proposed to illustrate the dependency of hydraulic resistance of membrane on the structural parameters such as average pore size, effective porosity as well as dip coating parameters like dipping time and concentration of CA. It was found that, the growth rate of CA film on the ceramic support followed exponential growth law with respect to dipping time. The total hydraulic resistance of the membrane was evaluated to be inversely proportional to the ratio of pore sizes of top layer and ceramic support. The resistance due to the CA film was found to be depended to the order of 1.73 with respect to concentration of CA. An increase in the concentration of CA was found to be more effective than dipping time to reduce the membrane pore size.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Filtration and Separation
Authors
B.K. Nandi, R. Uppaluri, M.K. Purkait,