Preparation and catalytic action of an asymmetric ethylene/vinyl alcohol copolymer‐copper complex membrane

Abstract

An ethylene/vinyl alcohol copolymer (EVA)-copper complex membrane was prepared by casting an EVA-CuC1, mixture (solvent : water-propanol (1 : 1 v/v) mixture) on a polyethylene substrate and then immersing it in 0,l M KOH aqueous solution. In the membrane, Cu was distributed asymmetrically in the direction of the membrane cross section. The distribution of Cu could be controlled by the temperature during preparation. The oxidation of hydroquinone during permeation through the complex membrane was performed using membranes with different Cu distribution. This distribution influences the permeation reaction. These results are well reproduced by a relation composed of Fick's law and Michaelis-Menten type reaction kinetics. Therefore, a good reactor can be developed by controlling the catalyst distribution. 0 1992, Huthig & Wepf Verlag, Basel CCC 0025-1 16X/92/$05.00

Permeation decomposition of urea through asymmetrically urease-immobilized ethylene-vinyl alcohol copolymer membranes

“…The tendency of R-side, by Method I, the concentration of decomposed urea through the urease-immobilized EVA the difference between Method I and Method II is similar to that in the permeation oxidation of membrane was approximately the same as that of the nondecomposed urea. In the R-side, by hydroquinone through an EVA-Cu complex membrane 12 and in the permeation hydrolysis of pMethod II, however, the concentration of decomposed urea through the membrane was higher nitrophenyl acetate through a CD-immobilized EVA membrane reported in our previous paper.…”

“…Consequently, an cross section. 11,12 The asymmetric distribution of catalyst is effective for the improvement of the asymmetrically urease-immobilized EVA membrane can be prepared by this method. membrane performance such as the separation of products.…”

“…11,12 The asymmetri-1): The EVA membrane was immersed in succescally catalyst-immobilized EVA membranes have sive, 1N aqueous NaCl solution, acetone solution a possibility as high-performance reactors. Thereof prescribed amount of cyanuric chloride, and fore, immobilization of urease on the EVA mem-20% aqueous acetic acid solution at 30ЊC for 30 brane may give us an excellent membrane for a min, and then dipped in a cold aqueous acetone hemodialysis.…”