Preparation of an extractant-impregnated porous membrane for the high-speed separation of a metal ion.
A novel impregnation method of extractants into a porous polymeric support is described. Bis(2-ethylhexyl)phosphate (HDEHP) was impregnated onto an n-octadecylamino group of the polymer chain grafted onto the pore surface of a porous hollow-fiber membrane. First, an epoxy-group-containing polymer chain was appended onto the porous membrane by radiation-induced graft polymerization of glycidyl methacrylate (GMA). Second, n-octadecylamine was added to the graft chain via an epoxy-ring opening reaction to yield a hydrophobic group density of 3.0 mmol/g of the GMA-grafted fiber. Finally, HDEHP was impregnated to the n-octadecylamino group. The amount of impregnated HDEHP of 2.1 mmol/g of the GMA-grafted fiber was attained while retaining the liquid permeability of the porous membrane. An yttrium solution was forced to permeate through the pores of the HDEHP-impregnated porous hollow-fiber membrane. The higher permeation rate of the yttrium solution led to the higher adsorption rate of yttrium because of a negligible diffusional mass-transfer resistance. In addition, a high stability of impregnated HDEHP was observed after the repeated use of adsorption with 50 mg-Y/L yttrium solution and elution with 7 M nitric acid.
Asai
Shiho
S
Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Chiba University, 1-33 Yayoi-Cho, Inage, Chiba 263-8522, Japan.
Watanabe
Kazuo
K
Sugo
Takanobu
T
Saito
Kyoichi
K
D002412:Cations; D008567:Membranes, Artificial; D008670:Metals / Q000302:isolation & purification*; D008855:Microscopy, Electron, Scanning
D002412:Cations; D008567:Membranes, Artificial; D008670:Metals