Photochemical isomerization of trans-azobenzene to ds-isomer, and its inverse cis-trans isomerization were investigated for the purpose of constructing a thermal energy storage system by conversion of solar light energy.Trans-cis photoisomerization of azobenzene in the cyclohexane solution proceeded with or without photosensitizers over a wide range of light in the ultraviolet and visible region. But the backward reaction from cis-to trans-form, which was predominant by the longer-wavelength light, set a limit to the progress of trans-cis conversion, and photochemical equilibrium was established at about 25 % conversion of mmv-azobenzene. Some devices to removethe conversion limit were examined. Cis-trans isomerization in the dark was carried out in the presence of immobilized metal porphine catalyst. Cotetraphenylporphine or Co-protoporphyrin fixed on polyethylene granules graft-polymerized with chloromethylstyrene was the most effective for the reverse reaction. This liberation of heat during the reaction was also analyzed from the kinetic point of view.

SynopsisVarious kinds of mercaptoethylated graft fibers were prepared and the abilities to adsorb the heavy metal ions were studied. 2-Hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and vinyl acetate were graft-copolymerized by irradiation onto five kinds of synthetic fibers and two kinds of foam polymers. Preirradiation a t low temperature was far more effective for grafting than simultaneous irradiation. The mercaptoethylation was carried out in the solution or in the vapor of ethylene sulfide onto the graft fibers treated with alkali. The mercaptoethylated graft fibers showed particular affinity for Hg and Ag ions. A few of the adsorption phenomena were pursued by flow experiment of the ionic solution through a column. The preliminary reduction of the mercaptoethylated graft fibers enhanced the capacity of adsorbing to three times that of the unreduced fibers. Effects of flow rate, pH, temperature, and concentration of Hg ion on the integrated adsorbed amount were also investigated.

Vapor‐phase graft copolymerizations of acenaphthylene–maleimide or acenaphthylene–maleic anhydride binary solid monomers onto poly(ethylene‐co‐vinyl acetate) films were carried out under ultraviolet irradiation. The extent of sorption of single or binary monomers increased with the increasing vinyl acetate content in the backbone polymers. The sorbed binary monomers were mainly composed of acenaphthylene, but the maleimide or maleic anhydride fraction increased with the increasing vinyl acetate content of the films and the composition was little affected by surface hydrolysis. In all series of graft polymerization of single or binary monomers the overall extent of grafting increased with the vinyl acetate content and was suppressed by the surface hydrolysis of the backbone film. The composition of the grafted copolymer, however, differed markedly, depending on the combination of binary monomers. The grafted copolymer in the acenaphthylene–maleimide system was composed mainly of acenaphthylene units, whereas that in the acenaphthylene–maleic anhydride system was composed mainly of maleic anhydride units. The results were compared with those of γ‐ray grafting, and it was suggested that the contribution of a direct supply of monomers from vapor phase and the existence of an acetoxy group on the surface of the film should play an important role in the grafting reaction.

SynopsisTriethoxyvinylsilane-styrene and triethoxyvinylsilane-methyl methacrylate binary monomers were polymerized by chemical initiation or by y-ray irradiation in the presence of silica gel, fire brick, quartz wool, and glass beads. The amount and composition of the polymers grafted to silicates were analyzed by using pyrolysis gas chromatography. When triethoxyvinylsilane alone was subjected to the reaction with silicates, condensation occurred irrespective of the initiating means, and the extent of the reaction was almost proportional to the specific surface area of the silicate. When binary monomer mixture was applied, incorporation of styrene or methyl methacrylate into the grafted polymer was observed whenever a monomer mixture of high styrene or methyl methacrylate content was submitted to the reaction. On each silicate, the relationship between the composition of polymer grafted on it and that of monomer showed a similar pattern in spite of the great difference of the specific surface area. Almost no participation of styrene or methyl methacrylate was observed when the silicate preirradiated in air or under vacuum was heated with the binary monomer mixture. It was concluded that triethoxyvinylsilane reacts with silicates by condensation and that some of the pendent vinyl groups on the silicates are incorporated into the copolymer with styrene or methyl methacrylate.

A suspension of TiSe2 in ethanol was illuminated with ultraviolet light in an atmosphere of Ar, air, or O2 at 298 K. The main products were acetaldehyde, acetaldehyde diethyl acetal (acetal), acetic acid, water, hydrogen, ethylene, methane, and carbon dioxide. Each yield of the products under air or O2 was higher than under Ar, except for that of hydrogen and ethylene. Platinum under an O2 atmosphere exerted its effect for producing CH3COOH, acetal, CO2, CH3CHO, CH4, and H2O, while under Ar it contributed to generating CO2, CH4, and H2. No effect of Pt was observed for generating C2H4 under either an atmosphere of Ar or O2.