Benzene was allowed to react with various perfluoroalkanoyl peroxides (CnF2n+1 (C0) OO (CO) CnF2n+1; n=1, 3, 4, 6, 8). The obtained products underwent sulfonations to give sodium fluoroalkylbenzenesulfonates (CnF2n+1-CnF2n+1C6H4-SO3Na ; n=4, 6, 8). The sodium fluoroalkylbenzenesulfonates showed excellent efficiency in reducing the surface tension of water, and the effectiveness in reducing the surface tension was enhanced by the increase of the number of carbon, n (n=4, 32. 8 (mN/m); n=6, 19.5 (mN/m); n=8, 15. 5 (mN/m) at 60°C). The microscopic polarities of the inside of those micelles were reduced as the number of carbon, n, increased. The liquid crystal phase (lamella phase) was found to exist in the concentrated aqueous solutions of sodium fluoroalkylbenzenesulfonates.
The effects of salinity and pH on the phase behavior, particle size, and ζ-potential of microemulsions with dimyristoylphosphatidylcholine (DMPC) were investigated. The addition of 1-propanol into DMPC/water/n-alkane systems resulted in the formation of an O/W-type microemulsion. The particle size of the microemulsion was independent of the concentration of n-alkane, but was decreased with increasing alkyl chain length of the n-alkane, the concentration of 1-propanol, and the salinity. The maximum additive concentration of n-alkane was considerably decreased at the regions above pH=7. The surface charge density of microemulsion changed from positive to negative with increasing pH, and became zero at pH=3.2. The particle size of the DMPC microemulsion was at its maximum in the isoelectric region (pH=3-7). It was found that the properties of the microemulsions are dependent extensively on both salinity and pH.
It was found that the polymerization of vinyl monomers, such as acrylamide (AAm), acrylic acid, and acrylonitrile, is initiated by a redox system consisting of ceric ion and acetylene black. The monomers were effectively graft polymerized onto the surface of acetylene black : The percentage of PAAm grafting onto acetylene black was increased with increasing conversion, and PAAm-gel-containing acetylene black was obtained at the conversion of about 30% or more. However, the system consisting of ceric ion and other carbon blacks having surface-oxygen-containing groups, such as furnace and channel blacks, failed to initiate the polymerization. Furthermore, carbon whisker and graphite powder had an ability to initiate the redox polymerization in the presence of ceric ion to give polymer-grafted carbon whisker and graphite powder. The relationship between the polymerization rate (Rp) and the concentration of acetylene black ([CB]), ceric ion ([Ce (IV)]), and AAm ([M]) was found to be given by the following equation : Rp=k [C13] 2 [Ce (IV)] [M]. The wettability and dispersibility of acetylene black were found to be remarkably improved by the surface grafting of polymers.
Stearic acid, oleic acid, linoleic acid, and linolenic acid were used for the modification of, TiO2 surface. The adsorbed states of the fatty acids on the surface of TiO2 were estimated from the adsorption behavior onto TiO2 and the wetting properties of the modified TiO2. The dispersibility of these TiO2 in an acrylic resin and the mechanical properties of their coating films having various pigment concentrations were measured. Main results were as follows : 1) Adsorption of the fatty acids on TiO2 was Langmuir type, and critical surface tension of the modified TiO2 increased with the degree of unsaturation of the fatty acids. 2) This modification was effective in improving the dispersibility of TiO2, which increased with the degree of unsaturation of the fatty acids. 3) The modulus of elasticity and Tg for the films increased with the degree of unsaturation of the fatty acids.
In this study, the nondestructive analysis of the dissolved water and the composition of coating films (aminoalkyd resin or polyurethane resin) on wood (birch or teak) was carried out by using the Photoacoustic near-infrared spectroscopy. 1) The dissolved water in the coating films and the wood could be determined by the absorption spectra (ν2+ν3) (1.92 μm, 1.94μm, 1.98 μm). The volume of the dissolved water in the aminoalkyd resin films was about twice of that in the polyurethane resin films. 2) The structural analysis of the aminoalkyd and the polyurethane resin films was carried out the absorption of methyl, methylen, phenyl, amido, imido, and carbonyl groups in near-infrared spectroscopy.
Hydroxyapatite has been prepared by the hydrolysis of calcium hydrogenphosphate. We have tried to increase the Ca/P molar ratio in hydroxyapatite and to raise the yield by adding calcium hydroxide particles having high dissolution rate, which was prepared from active calcium oxide and hot water to the reaction system. It was revealed that a lower addition rate of calcium hydrogenphosphate to the reaction system, and higher reaction temperature and dissolution rate of calcium hydroxide tended to increase the Ca/P molar ratio. The highest value of the Ca/P molar ratio of the solid product obtained in this study was only 1.44. This value was too small in comparison with the theoretical value of Ca/P molar ratio of stoichiometric hydroxyapatite. The reason for the disagreement was discussed. The solid product (Ca/P molar ratio=1. 44) obtained in the heterogeneous reaction changed to β-calcium phosphate particles by heating at 1000°C for 180 min.
The derivatives of 3-hydroxyphenylphthalide containing indolizines and indolizine like heterocycles were prepared by the condensation of 2-(4-hydroxybenzoyl)-5-dimethylaminobenzoic acid with indolizines and indolizinelike heterocycles in acetic anhydride. The effect of the substituents on the visible spectra in acetic acid or aqueous methanol solution of sodium hydroxide was investigated. These derivatives were colored both in acetic acid and aqueous methanol solution of sodium hudroxide. The compounds containing indolizines and imidazo- [1,2-a] pyridines had longer λmax than the corresponding derivatives containing indoles.
KNiPO4. H2O was synthesized by the reaction between Ni3 (PO4) 2.8 H2O, known as a raw material of nickel yellow and K2HPO4 in water at 96°C, and its thermal change was investigated. KNiPO4?H2O with platy crystal of light greenish yellow (Pe : 19. 0%, Y : 88. 1%, λd : 569.4 nm) changed to a new phase of low-temperature-type KNiPO4 (pale yellow ; Pe : 22. 8%, Y : 59. 0%, λd : 579. 5 nm) by dehydration at 263°C, and to KNiPO4 at the transition temperature of 590°C. The color of KNiPO4 obtained by heating at 900°C was brilliant yellowish red (Pe : 58. 0%, Y : 12. 0%, Ad : 592. 5 nm) because of the five-coordinated Ni2+ion. The color of MI NiPO4 (MI : Li, K, Rb, Cs) synthesized by the solidstate reaction was measured. Their colors turned from yellow to yellowish red, reddish purple and bluish purple with increasing ion radii of alkaline metals and with decreasing coordination number of Ni2+ ion.
This study deals with the surface modification of wood by utilizing CVD to obtain uniform staining and good finishing. BaSO4 used as transparent fine particle was dispersed in solvent mixture, and this suspension was coated on birch and oak wood. Then, 1,3,5,7-tetramethylcyclotetrasiloxane (H-4) was deposited on the coated BaSO4 in gas phase under reduced pressure. The followings were found after the investigation on the staining and finishing of the surface-modified wood. 1) Modified surface was smoother and more porous than the original wood. 2) Staining unevenness for the original wood was improved by the coating of BaSO4 particle. The addition of polymerized H-4 layer on BaSO4 surface was more effective.
The chemical vapor deposition of 1,3,5,7-tetramethylcyclotetrasiloxane (H4) was employed on titanium dioxide, in which H4 was polymerized to form a coating layer of poly (methylsiloxane) (PMS). TiO2 modified with alcoholic hydroxyl groups was synthesized from PMS-coated TiO2 by hydrosilylation. The OH groups on TiO2 were confirmed by Fourier transform infrared spectrophotometry and thermal analysis. Since TiO2 modified with OH groups inhibited the dehydration of t-butyl alcohol and did not absorb, dl-a-tocopherol, active sites hardly existed on the surface. From dispersibility and contact angle measurments TiO2 modified with OH groups was found to be hydrophilic. The dispersibility was influenced by the density of OH group on the surface and the number of OH group in a PMS molecule on TiO2.