Rationally designed wedge-shaped amphiphiles self–assemble in water to form organic nanotubes consisting of monolayer lipid membranes. The organic nanotubes with a well–defined size dimension and functional inner and outer surfaces can provide a one–dimensional hollow cylinder that functions as a meso-scale host to encapsulate,transport, or release nanometer–scale guests like protein molecules. Confinement effect, which depends on the sizebalance between the nanotube inner diameters and the guest proteins, allow the nanotube to stably storage those guests while keeping the biological activity under harsh conditions of temperatures and denaturant concentrations.Thus, the organic nanotubes can be expected as novel soft materials that are widely applicable in biological and medical fields.

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Reverse osmosis (RO) process is one of the most effective processes to solve the water shortage problem. The large scale RO plants have been acceleratingly constructed in the world. Nowadays polyamide membrane and cellulose triacetate membrane were commercialized as the RO membrane. Recently much attention has been paid again on development and modification of the RO membrane due to the increased interest on water shortage. Here we review briefly 1) RO membrane formation by interfacial polymerization method, 2) New sulfonated polymers for RO membrane, 3) Surface treatment of RO membrane and 4) RO membrane preparation by layer–by–layer method. In the RO membrane development by interfacial polymerization, continuous efforts have been made to acquire further higher water flux and higher chlorine resistance. New sulfonated polymers were explored for RO membrane with high chlorine resistance. In addition, the surface treatments mainly on the commercial membranes still attract much attention for achievement of anti–fouling property. Alternating electrostatic layer–by–layer (LbL) assembly of cationic and anionic polyelectrolytes on porous supporting membranes is another candidate for RO membrane. The possibility of this LbL membrane for RO membrane will be discussed.

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Inorganic membranes and organic–inorganic membranes used for water treatment are reviewed. First, inorganic membranes are briefly introduced in terms of their advantages, manufactures, and materials. Second, some recent topics of inorganic membranes are summarized, including commercialized large–scale modules (180mm in diameter, 1,000/1,500 mm in length; 15/24 m2) which have been applied for drinking–water production. TiO2 nanoporous membranes with molecular weight cut–off in the range of 200 ～ 2,000 by sol–gel processing were successfully prepared, and applied to high temperature nanofiltration and possible “photo–cleaning” of foulants by photocatalysis. Finally, new applications of inorganic membranes are introduced, including carbon nanotube membranes with superpermeability and zeolite membranes for desalination. Organic/inorganic hybrid membranes in RO/NF and UF/MF are also summarized.

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The reverse osmosis (RO) membrane plays a significant role in pure water production, waste water reuse, and valuable material recycle systems. Among RO membrane technologies, methods to seek and reduce membrane fouling sources, RO rejection increasing treatment, and the phosphate acid recycle system are presented in this paper.
Engineering companies have to develop technologies to obtain and maintain higher RO performance, also those to contribute resource saving and valuable material recycle.

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Private sectors and public sectors related to water treatment business in Japan have been quite active in recent years. More than 40 companies in the private sector formed “Global Water Recycle and Reuse System Association, Japan” (GWRA) in 2008 to build up a platform of the business for water recycle system and to expand it to overseas. Japanese government such as METI, MOE, MLIT and CAO have been very active in promotion of water related R&D and private sector’s water business supporting programs. The outline of the project such as NEDO’s project on “Water–saving Recycling System”, JST/CREST’s “Development of innovative technologies for realizing sustainable water management by mitigating water”, MLIT’s “Advance of Japan Ultimate Membrane Bioreactor technology : AJUMP”, CAO’s FIRST Program “Megaton Water System” and so on are introduced.

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Membrane technology is regarded as a promising means to reduce the cost of carbon dioxide capture and storage (CCS) for global warming problem. In this paper, three types of CO₂ selective membranes were investigated for separation of CO₂/N₂ in order to remove CO₂ from the flue gas: poly(ethylene glycol) based membranes, Cs–incorporated carbon membranes and dendrimer composite membranes. In development of poly(ethylene glycol) based membranes, crosslinked poly(ethylene glycol) diacrylate membranes were prepared using water as the solvent and UV polymerization. Swelling behavior and separation performance were affected by preparation conditions, especially water concentration in polymerization mixture. In development of Cs–incorporated carbon membranes, the original carbon membrane without Cs had a lower CO₂ permeance and CO₂/N₂ separation factor under humid conditions than it did under dry conditions. On the other hand, Cs-incorporated carbon membranes had a higher CO₂ permeance and separation factor under humid conditions. It was suggested that the change in pore size distribution and the pore surface properties played an important role in improving CO₂ separation performance under humid conditions. In development of dendrimer composite membranes, a commercial-sized module of PAMAM dendrimer composite membrane, with length 1,100 mm, diameter 35 mm, and membrane area 0.4 m², was developed using the insitu modification (IM) method. Also, a long–term stability test (a separation experiment continuously running for 1,000 h) was conducted using an 800 mm module and real exhaust gas at a steel manufacturing plant. It was demonstrated the membrane module was stable for at least 1,000 h of exposure to real exhaust gas.

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Membranes from quaterinized chitosan (QCh), which was a derivative of marine (natural) polymer, and sodium 1- dodecylsulfate (C12SNa) transported ethanol in preference to water by vapor permeation. Membrane performance, such as permselectivity and flux, was enhanced with the increase in amphiphile (C12S) content in the membrane. The results suggested that the QCh–C12S complex membranes were applicable to selective separation of bioethanol from fermentation broth.

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Characterization of membrane porosity is important to evaluate separation efficiency. Through pore size relate to separation size, permeation rate relate to efficiency of separation. Now a day, we have two permporosimetry techniques for evaluation these pore. One is bubble point method by pressure which can determine 15 nm ～ 500 μm in pore diameter. Another technique is permporometry method by changing vapor pressure which can detect 0.5 ～ 50 nm pore size.

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