Takako Nagase

Preparation of porous chelating resin containing linear polymer ligand and the adsorption characteristics for harmful metal ions

Abstract A linear copolymer consisting of maleic anhydride and methylvinylether has been immobilized on the interior surface of porous polymer beads. The modified polymer beads thus obtained have formed the starting material for the preparation of metal selective chelating resins by the reaction of the maleic anhydride moiety with appropriate ligands. Cysteamine has been grafted as the pendant ligand and the resulting chelating resin (cysteamine resin) maintains a high porosity and large specific surface area. On the basis of scanning electron microscopy (SEM) and electron dispersion X-ray (EDX) analyses, the linear polymer is distributed from the outer layer to the inner pores of the resin beads. The adsorption characteristics of the cysteamine resin for Cd 2+ and Pb 2+ have been examined with respect to the percentage extraction, adsorption isotherm and reproducibility upon adsorption–regeneration cycles. The chelating resin shows a remarkably high adsorption rate, which has been attributed to the porous nature of the resin and geometrical flexibility of the ligand. Quantitative removal of Cd 2+ and Pb 2+ from aqueous solution has been demonstrated by the column procedure packed with the cysteamine resin.

Combinatorial Methodology on Zeolite Membrane Development for Organic Chemical Process Intensification

Combinatorial methodology for zeolite membrane development is discussed. Zeolite membrane is now attracting attentions as an energy-saving separation apparatus via pervaporation and/or vapor permeation, but sometimes it suffers performance (flux and/or separation factor) deterioration due to lack of chemical stability. We separate the development scheme into three steps – i) zeolite selection via chemical affinity and stability evaluation in powder applying combinatorial methodology, ii) membrane preparation for thus selected zeolite species, and iii) their evaluation in parallel manner. We have successfully developed hydrophilic zeolite membranes with tolerance against acidic environment. Thus developed zeolite membranes were successfully applied esterification reaction from a stoichiometric mixture of a carboxylic acid and an alcohol by assisting equilibrium shift via direct pervaporation from crude reaction solution.