Masakazu Yoshikawa

Photo-induced carrier mediated transport of alkali metal salts

Abstract A new, long-alkyl-group spiropyran compound, 1-octadecyl-3,3-dimethyl-6′-nitrospiro(indoline-2,2′-2H-benzopyran), was synthesized which showed photochromism similar to spiropyran compounds reported previously. Its ability as a salt transporting carrier was investigated by using it in a 1-octanol liquid membrane. The salt NaCl was concentrated from the dark to the visible light illuminated side across the anisotropic membrane using the conditions whereby one interface between liquid membrane and aqueous phase was illuminated with visible light and the remaining was kept dark. In the KClue5f8NaCl binary system, more NaCl was transported than KCl.

Modified polysulphone membranes: 1. Pervaporation of water/alcohol mixtures through modified polysulphone membranes having methyl ester moiety

Abstract Membranes were prepared from modified Udel P-3500 polysulphone having methyl carboxylate groups, of which the degree of substitution ranged from 0.05 to 1.90 ester groups per repeat unit. The membranes showed permselectivity towards water in the pervaporation of aqueous alcohol solutions.

Novel liquid membrane transport system for tryptophan

Abstract Transport of an amino compound, tryptophan, was carried out with a liquid membrane incorporating a lipophilic aldehyde, 4-octadecyloxybenzaldehyde, as a carrier. In the present membrane transport system, a reversible organic reaction, Schiff base formation between the amino group in tryptophan and the formyl moiety in the carrier was utilized as a molecular recognition reaction.

A calorimetric study of various alcohols in a poly(dimethylsiloxane)membrane

Abstract The state of various alcohols with carbon numbers from one to eight in a poly(dimethylsiloxane) (PDMS) membrane was investigated by d.s.c. Methanol, ethanol, 2-propanol, 1-butanol and 1-pentanol were present in the PDMS membrane in the bound state as well as in the bulk state, while 1-octanol was comprised only of free 1-octanol. The amount of bound alcohol increased with increase in the carbon number up to four and then decreased with further increase in the carbon number. We concluded that the interaction between the methyl group in the PDMS membrane and the alkyl moiety in the alcohol was a specific interaction to form bound alcohol in the PDMS membrane.