Effects of polymerizable groups on aqueous phase behavior of monomeric and gemini surfactants have been studied on the basis of visual appearance, polarized optical microscopy (POM), and small angle X-ray scattering (SAXS) data. Three phases were observed for non-polymerizable monomeric (UTAB), polymerizable monomeric (PC11), and non-polymerizable gemini (11-6-11) surfactants: micellar solution (Wm), hexagonal (H1), and lamellar gel (Lβ) phases. In the case of a polymerizable gemini surfactant (PC11-6-11), we saw a lamellar liquid crystal (Lα) phase between the H1 and Lβ phases (i.e., Wm-H1-Lα-Lβ phase transition). Polymerizable groups covalently bound to the terminal hydrocarbon chains resulted in an increased Wm-H1 phase transition concentration for both the monomeric and gemini surfactants. It seems that this is due to the loosely packed hydrocarbon chains of the polymerizable surfactants in their molecular aggregates. We also found that the gemini surfactants yield a lower Wm-H1 phase transition concentration (in mol/L) than the monomeric ones, as a result of an increased critical packing parameter and/or an increased hydrophobicity of the gemini surfactants.
We prepared 9,10-bis(phenylethynyl)anthracene (BPEA) fineparticles by the reprecipitation method; an acetone solution of BPEA was injected into water. We studied the spectroscopic properties of the yellow dispersions by using dynamic light scattering, absorption and fluorescence spectra and lifetime measurements. The average diameters of the fineparticles were obtained to be 83 to 122 nm by dynamic light scattering. The absorption spectra of the dispersions showed peaks between those of BPEA in acetone and bulk crystals. The fluorescence spectra of the dispersions showed peaks at around 525 and 600 nm. The main component of the lifetimes for the former band was about 0.2 ns and the fluorescence intensity of the band increased with a decrease in the size of the nanoparticles after filtration. The fluorescence around 525 nm was thus assigned as being intrinsic to the BPEA nanoparticles. The main component of the lifetimes for the latter band was about 50 ns and the fluorescence peak agreed with that of the bulk crystals, indicating that the nanoparticles also showed the same fluorescence as the bulk crystals.
The number of the report concerning the nanoparticle synthesis using microwave heating is remarkably increasing lately. Since the high quality nanoparticles can be obtained by the simple operation compared with the conventional nanoparticle synthetic method, many researches intended for industrialization have been carried out (or proceeded, or on the move). In this review, various features and examples of the nanoparticle synthesis by microwave were summarized. Moreover, in order to clarify the feature of the microwave method, we also added general description of nanoparticles.
Photographs of the reactor after the sample discharge (a) after 5 min of microwave irradiation, and (b) after 5 min of oil bath heating. Illustrations represent the temperature distribution in the reactor (c) by microwave and (d) oil bath heating33).
Oily gels are solid or paste materials in which oils are solidified with small quantity of fixation agents. They are mainly used as base of makeup cosmetics. In this article, control methods of the hardness of oily gels, novel solidification method of silicone or fluorine oil, and oil separation phenomena were explained based on the micro structure of oily gels.
Solid surfaces constitute a field of chemical reaction and a direct interface against other substances, light, heat, and electric charges for the solids themselves. Recently, multiple and high level functionality has become necessary for industrial materials, but the intrinsic properties of specific materials are often insufficient to completely satisfy all industrial requirements. To satisfy current requirements, surface-functional materials are attracting great attention. The specific nature of solid surfaces is the remarkable nature of the properties of molecules and atoms once they satisfy certain conditions such as chemical composition or the position on the surface. Characterization and analysis of solid materials at the nanoscale level is indispensable for surface function design. Based on this background, we are planning to include a “Current Surface Science Course” in our society journal. To introduce the course, the current paper uses surface wettability as an example to present the relationship between solid characteristics and surface properties, in addition to showing the contribution of surface characterization to elucidate surface functions.