Coordinatively Polymerized Bilayer Membranes Prepared with an Amphiphilic Derivative of 2-Thiazolylazophenol in Water

In search of new amphiphiles that form coordinatively polymerized bilayer membranes (CPBMs) in water, N-dodecyl-3-[2-hydroxy-3-(4-carboxymethyl-2-thiazolylazo)-5-methylphenyl] propanamide (5) was prepared. The bilayer membranes of 5 prepared in the presence of 2 equivalents of NaOH were further sonicated in the presence of transition metal ions such as Ni(II), Cu(II), Co(II), or Co(III) at >80°C to obtain CPBMs. The CPBMs of 5 were characterized by transmission electron microscopy, gel filtration, resistivity against disruption in aqueous ethanol, visible spectra, and release of entrapped 5(6)-carboxyfluorescein. Remarkable stabilization of the bilayer membranes through coordinative polymerization was evidenced by the resistivity of the Ni(II)-CPBM of 5 against disruption in 40%(v/v) ethanol upon incubation for 20 hr.