The area based-society can be defined as a life base which is extended from the riverhead to the coastal zone. Water, food and energy are inputted into it and wastewater, solid waste and air pollutants are outputted from it. Water and wastewater occupy almost 100% in weight among them. In order to establish the sustainable metabolic system in the area-based society, it is essential to develop the leading-edge water and wastewater treatment system for the recycling use of water and the recovery of valuable resources such as phosphorous from the wastewater. Membrane technology is a key in such a leading-edge technology. The membrane filtration has been applied to the water purification and municipal wastewater treatment in EU and USA since early 1990s. In Japan, membrane filtration has been applied mainly to the water purification. But the portable water produced by the membrane filtration process occupies only 1.0% of the total portable water production in Japan at this juncture. The 3rd Science and Technology Basic Plan has started in April 2006. It adopts the development of the leadingedge technology for water and wastewater treatment using membrane as a future Japanese technology for the global use, which can contribute to build a healthy water metabolic system and sustainable use of water. This paper deals with the concept and performance of hybrid membrane water purification system obtained in the author’s laboratory.

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In this paper, we show a strong enzymatic basis for catalytic subunit interaction in tetoraprotomeric Na/K-ATPase, recently obtained, which have not been reported before except our preliminary report and may be useful for a better understanding of the mechanism of P-type pump ATPase in general. The oligomeric nature of Na/K-Transport ATPase was reviewed previously.

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A novel modeling technique, which combines molecular simulations with a permeation theory, for a prediction of gas permeability through zeolite membranes is proposed. Permeability of hydrocarbons and inorganic gases through an MFI-type silicalite membrane was systematically predicted by using this technique. The estimated permeability were in agreement with the experimental data, although they were an order of magnitude larger than those previously reported in experimental studies. This diversity is because of the effect of the grain boundary that was examined by further studies using PFG-NMR and molecular simulation. Permeation by various single gases (H2, He, Ne, Ar, O2, N2, CO2, CH4) through different density amorphous silica membrane models has been investigated using the grand canonical ensemble molecular dynamics (GCMD). Molecular trajectory analysis clearly reveals the occurring molecular sieving and that He has many permeation paths in the membrane in addition to the path of H2. The transition boundary of the temperature dependence of gas permeability through molecular sieving membranes was also investigated by GCMD, using membrane models having cylindrical pores with a pose size range of 0.3 - 0.5 nm. Activated transport was found when the pore size of the membrane became smaller than 1.3 times that of the molecular diameter of the permeating species. Consequently, molecular modeling techniques are approved as powerful approach for the investigation of permeation mechanism and prediction of gas permeability in ceramic membranes.

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Aqueous dispersions of lyotropic liquid crystalline phases (cubosomes and hexosomes) were prepared by highpressure emulsification using lipid mixtures, monoolein (MO) and oleic acid (OA), and an emulsifier Pluronic F127 with changing their composition. Small-angle X-ray scattering experiments confirmed the presence of the liquid crystalline phases in the particles. The lipid ratios and solvent pH strongly affected the morphology of the internal structure of the particles. By increasing the weight fraction of OA in the lipid mixtures, the internal structure transformed in the order of bicontinuous cubic-inverted hexagonal-inverted cubic. In addition, transformation from the cubosome to the hexosome was observed by decreasing the pH, suggesting that the interior of the nanoparticles is responsive to the outer environment. 13C NMR experiments with paramagnetic shift reagent showed that the signal of carbonyl carbon of oleic-1-13C acid mixed in the particles readily shifted to a lower magnetic field by addition of europium ion (Eu3+), indicating high accessibility of the ion into the water channel inside the particles. Phase behavior and the changes in the local orientation order of lipids in a binary system consisting of phosphatidylcholine and MO were also investigated. Time-resolved fluorescence anisotropy measurements using cubosomes and liposomes revealed that the order parameter of the probe in the lamellar phase increases with increasing MO, and that it decreases during the transition to the bicontinuous cubic phase. This observation suggests that the lateral pressure in the acyl chain regions increased by the addition of the nonlamellar-forming lipid is released by the phase transition.

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A new type of mesoporous membranes and films from a material with periodic structure has been developed. A membrane made of MCM-48 with a three-dimensional pore structure was deposited on a porous alumina support under hydrothermal conditions. The silylation with trimethylsilane and triethylsilane was used to enhance hydrothermal stability and hydrophobicity of the MCM-48 membrane. The silylated MCM-48 membranes were used for the separation of ethanol (EtOH), methylethylketone (MEK), and ethylacetate (EA) in aqueous solution. The separation factor and the flux were higher in the order: EA (351) > MEK (201) > EtOH (11) at 30℃, which was related to the hydrophobicity of organic molecules. Furthermore, the hydrothermal stability of the MCM-48 membrane was improved by the silylation. The mesoporous Zr containing MCM-48 (Zr-MCM-48) membranes were synthesized on a porous alumina support. The Zr-MCM-48 membranes are stable in the alkaline solutions at pH 9-12. A small amount of Zr in the MCM-48 effectively enhanced structural stability in alkaline solutions. The Kelvin diameter of the Zr-MCM-48 was estimated to be about 2.5 nm from the permporometry measurement. From the filtration results, the Zr-MCM-48 has very a narrow pore size distribution and MWCO of about 3800 Da which corresponds to ca. 2.3 nm in size. Mesoporous silica films have conventionally been prepared by liquid deposition methods. On the contrary, we have demonstrated a vapor phase synthesis to prepare ordered mesoporous silica films. In this method, the surfactant films were exposed to tetraethoxysilane (TEOS) vapor. We have found nano-phase transition of surfactant-silicate composites under vapor infiltration of TEOS. The phase transition of the nanocomposites under vapor infiltration implies their high mobility in the absence of solvent. When triblock copolymer was used as a surfactant, the silica thin films with two-dimensionally connected cage-like mesopores were formed. The films show lower concentration of residual Si-OH group compared to the film prepared by a conventional sol-gel method. The films show high thermal stability up to 1000℃ and high hydrothermal stability. The vapor-phase synthesis can be applied for organicinorganic nanocomposites and mesoporous metal oxides other than silica and provides opportunities for the creation of new materials technologies.

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Membrane emulsification using Shirasu-porous-glass (SPG) membranes is a novel method for preparing monodispersed emulsions. In this study, effects of interfacial tension, and viscosities of dispersed and continuous phases on droplet formation were investigated using various surfactant concentrations and various dispersed and continuous phases. Decane was pressurized into a stirring sodium dodecyl sulfate (SDS) aqueous solution in an interfacial tension range of 4.7 to 35.7 mN･m–1 through a SPG membrane with a mean pore diameter of 3.1μm, at a transmembrane pressure larger than capillary pressure. Under these conditions, monodispersed oil-in-water emulsions with a mean droplet diameter of approximately 10μm were stably prepared. Oil-water interfacial tension barely affected the resulting droplet diameter. In a system composed of decane containing liquid paraffin and SDS solution containing polyethylene glycol, experimental results showed that the resulting droplet diameter increased with increasing waterphase viscosity, while droplet diameter decreased with increasing oil-phase viscosity. Droplet diameter decreased as the ratio of oil-phase to water-phase viscosity increased. However, droplet diameter did not change in the case of a constant viscosity ratio.

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Liposomes have attracted interests in cosmetic industry but there are few liposome products on this market. One of the reasons is their structural instability during long-term storage. There are many published studies on the effects of liposomes on percutaneous absorption. However, due to varying experimental conditions, no positive conclusion can be reached regarding their effects. We show important factors affecting liposomal stability and examine the percutaneous absorption of these liposomes, and demonstrate their topical effects on the skin.

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