Positron annihilation technique as a probe of subatomic vacancies is described for non-positron polymer scientists. Although positronium (Ps) is an unparalleled unique probe of inter-molecular vacancies in insulating materials, with both its intensity and mean lifetime carrying information about the free volume, the processes that lead to these physical quantities are not simple. The state-of-the-art understandings of how Ps is created and how its mean lifetime is determined in vacancies are described, and examples of the unique feature as well as the problems and precautions are illustrated.

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A “Biomembrane”is a key interface to integrate production and separation of target materials through the creation of “new order”on its surface. A novel biomembrane-based catalysis (LIPOzyme: liposome＋enzyme)can be designed and developed by using the recognition function of the liposome under stress condition. A process design utilizing LIPOzyme as a core material is the basic strategy to achieve a “Biomembrane Process chemistry” as an application of “Membranomics”.

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Permselectivity and efficiency in membrane separation are greatly dependent on a couple of factors, such as solubility, in other words, affinity between a membrane and a target substrate and diffusivity of the given substrate. Among those two factors, it can be regarded that the former is arbitrarily controlled a wide range compared with the latter. From this, it is indispensable to introduce molecular recognition site, which rigorously discriminate between the target molecule and others, into synthetic membranes so that those membranes may transport it with high efficiency and selectivity. Molecular imprinting is regarded as one of the most facile methods to introduce molecular recognition sites into synthetic membranes and various separation membranes were prepared by molecular imprinting. Instead of pioneering ‘molecular imprinting’, emerging ‘alternative molecular imprinting’ can directly convert various polymeric materials into molecularly imprinted materials or molecularly imprinted membranes. In order to obtain molecularly imprinted membranes with high flux and high permselectivity, electrospray deposition is one of plausible methods. To this end, polymeric materials were directly converted into molecularly imprinted nanofiber membranes by simultaneously applying electrospray deposition and alternative molecular imprinting. In the present review, the application of molecular imprinting to membrane separation will be surveyed.

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Over the past decades, there is a worldwide interest in zeolite membranes because of their high thermal stability, high chemical resistance, high mechanical strength and molecular sieving properties. Pervaporation (PV) has advantages in separating azeotropes, close–boiling mixtures, and thermal sensitive compounds, and removing species present in low concentrations. Zeolite membranes are thus well suited for separating liquid–phase mixtures by PV. By now, LTA membranes with high selectivities and high fluxes for the separation of alcohol / water mixtures by VP for biomass ethanol have been commercially available by some company. In order to more widely use of zeolite membrane, for example, a search of membrane materials with higher acid-stability is still important. Here, unique micro-pore system property of some kind of zeolite which is one of the candidates for new zeolite membrane materials are discussed. And also review effects of zeolite layer itself, inner and outer substrate under the PV operation and the new estimate method for PV by using mass spectrometry.

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Research and development of palladium–based composite membranes and their application to membrane reactors to produce hydrogen for PEM fuel cells are surveyed. The topics are the long–time stability of thin palladium membranes, especially palladium/porous-substrate composite membranes fabricated by electroless–plating, in the steam reforming of hydrocarbon fuels, and the diversification of long–carbon–chain fuels usable in the membrane reactors. The stability of the thin palladium membranes was related to the formation and enlargement of defects, mainly caused by the intervention of impurities, the sintering of palladium grains, and the adhesion of metal particles. In the　application of palladium membrane reactor to the steam reforming of desulfurized kerosene, the formation of long-carbon–chain byproducts in pre–reforming might lead to the decreased hydrogen permeance of palladium membranes, resulting in relatively low hydrogen yield in the membrane reactor. A highly active and selective catalyst for the pre–reforming should be developed for the hydrogen production from kerosene using the palladium membrane reactor.

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Computational chemistry technique has been applied to the study of functional materials including membrane sep-aration medium for the past a decade. These studies have provided important findings regarding to separation mech-anism as well as the detail structure of membranes from the microscopic point of view. We have recently proposed“combinatorial computational chemistry”, “multiscale computational chemistry”and “multi–physics computationalchemistry”as new concepts for useful tool to develop novel functional materials. Combinatorial computational chem-istry is a methodology for theoretical material screening to seek optical membrane for particular separation system.Multiscale computational chemistry and multi–physics computational chemistry are concept combing different theo-retical methods that are validated only for individual time or size scales, which is useful for seamless understandingof interested phenomena from micro-scale to macro–scale. In this paper, some theoretical studies based on this newconcept are presented. The applications to membrane characterization of dialysismembranes, theoretical screeningmethodology for porous membranes for specific gas purification, degradation mechanism of polymer electrolytemembranes in fuel cell, and modeling of fouling in water purification system are discussed.

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A novel preparation scheme for size-exclusion polymer chain, capable of adsorbing low–molecular–mass targetswhile retarding proteins, was suggested. An epoxy–group–containing vinyl monomer, glycidyl methacrylate, waspolymerized onto a polyethylene–made porous hollow–fiber membrane by radiation–induced graft polymerization.Water was added to the epoxy group of the graft chain, followed by the reaction of the remaining epoxy group withtrimethylamine. Phosphate ionic species were adsorbed to the resultant anion–exchange porous hollow–fiber mem-brane, whereas bovine serum albumin (BSA)was not bound to the membrane. This remarkable difference in thebinding characteristics was explained by a distribution of the functional groups along the graft chain: a shrunken con-formation in the upper part of the graft chain exclusively containing the diol group retards BSA and accepts phos-phate ionic species. In contrast, a swollen conformation in the lower part along the graft chain exclusively containingthe trimethylammonium group captures the phosphate ionic species invading the upper part. The successive addi-tion of the reactantsin the introduction of the modification of the epoxy group of the graft chain provided a size exclu-sion structure for the graft chain.

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A solid–in–oil (S/O)solution containing L–ascorbic acid phosphate magnesium salt (VC)was prepared to investi-gate the permeation behavior of VC into epidermis and dermis. The VC was coated with hydrophobic surfactant mol-ecules. Therefore, the coated–VC was well dispersed in an oil phase. Using a Yucatan micropig skin as a model skin,we validated if the S/O technique is applicable to carry a hydrophilic biomolecules into the cutaneous tissue. Theobservation of the cross-sectional skin by a fluorescent microscope confirmed that VC is present inside the skin tis-sue. The results indicated that the S/O solution can deliver VC into the skin. Since VC works as an inhibitor againstmelanin formation at epidermis and dermis, it is suggested that the VC–S/O solution can be applied to a whiteningagent and a cosmetic ingredient.

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An immobilized metal affinity porous membrane of a hollow-fiber form was applied to the purification of geneticallyengineered histidine (His)–tagged fusion protein. An iminodiacetate (IDA)group (–N(CH2COOH)2)was introducedinto the poly–glycidyl methacrylate chain grafted onto a polyethylene-made porous hollow–fiber membrane.Subsequently, nickel ions were bound to the IDA group before the permeation of a His–tagged green fluorescent pro-tein (GFP)solution through the porous membrane. The resultant immobilized nickel affinity porous membrane(immobilized Ni membrane)had a ligand density of 0.36 mol/kg and a phosphate buffer flux of 0.4 m/h at a perme-ation pressure of 0.1 MPa and 298 K. His–tagged GFP adsorbed to the immobilized Ni membrane was eluted by per-meating a 0.5 M imidazole solution through the porous membrane. From an SDS–PAGE analysis, the purity of theprotein was found to be improved from 35 to 97%.

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Ultrafiltration with plate & frame membrane system is used for the recovery of 2–keto–L–gulonate (2KLG), animportant intermediate of vitamin C in Northeast General Pharmaceutical Factory, China. Ultrafiltration is a newprocess to remove proteins and bacterial debris in the fermentation broth and the membrane process shows advan-tages over other processes, e.g. precipitation or flocculation. Results of ultrafiltration with two different membranemodules, Alfa Laval M38 and M39 are presented and compared with respect to the characteristics of the two mod-ules. This work shows that fermentation broth without pre-treatment (e.g. centrifugation)can be filtered with the lat-est module M39. The membrane process has been operating in the production line for more than 10 years inNortheast General Pharmaceutical Factory, and the operational experience is summarized in the paper.

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