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Volume 31 (2006)
- Issue 6 Pages 290-
- Issue 5 Pages 226-
- Issue 4 Pages 180-
- Issue 3 Pages 157-
- Issue 2 Pages 83-
- Issue 1 Pages 2-
Volume 31, Issue 6
Displaying 1-9 of 9 articles from this issue
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Review Article
Special Issue
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Hiroyoshi Kawakami2006 Volume 31 Issue 6 Pages 290-295
Published: 2006
Released on J-STAGE: June 19, 2015
JOURNAL OPEN ACCESSLiposomes are well known to be drug carriers of the phospholipid bilayer with potential application in drug and gene deliveries. However, the cellular uptake of liposomes generally follows an endocytic pathway so that most liposomes remain entrapped endosomes and are unable to reach the cytoplasmic space. To overcome this problem, pHsensitive liposomes, which are designed to undergo rapid destabilization in the acidic environments of endosomes, have been synthesized. We report the novel design of an antioxidante or anticancer drug delivery system based on a pH-sensitive liposome retaining the metalloporphyrin as an SOD mimic. The liposomes contained cationic/anionic lipid combinations and were composed of Fe-porphyrin, L-a-phosphatidylcholine (DMPC), dimethylditetradecylammonium bromide (DTDAB), sodium oleate (OANa), and Tween-80. The size of the liposome was approximately 30nm, indicating that the resulting liposome was a nanoparticle.View full abstractDownload PDF (774K) -
Yukikazu Takeoka2006 Volume 31 Issue 6 Pages 296-301
Published: 2006
Released on J-STAGE: June 19, 2015
JOURNAL OPEN ACCESSWe prepared porous polymer gels using a colloidal crystal as a template. The porous structure endows a structural color to polymer gels. We found that the peak position of the reflection spectra from the porous gels (λmax) is expressed as a function of the swelling degree, and is synchronized with the change in the swelling degree. We can estimate the linear expansion factor α of the subchains by comparing the peak position at a given situation (λmax) and the reference state (λmax, 0), in which the subchains behave as Gaussian coils. Creating the periodically ordered structure, which is similar in size to the wavelength of optical light, in the gels allows us to determine the behavior of polymer chains by observing the structural color.View full abstractDownload PDF (781K) -
Junji Saito, Jian Ping Gong, Yoshihito Osada2006 Volume 31 Issue 6 Pages 302-306
Published: 2006
Released on J-STAGE: June 19, 2015
JOURNAL OPEN ACCESSHydrogels are attractive materials with permeation and stimuli-responsiveness etc. But applications of hydrogels are confined because of the lack of mechanical strength. The author’s research group recently developed a general method to obtain very strong gels by introducing a double network (DN) structure. These high strength hydrogels, containing 90% water, exhibit a high compressive capacity as high as decades of MPa and show a high wear resistance due to their extremely low friction as 10–4. The authors’ group also succeeded in making strong gels with biocom atibility by introducing natural polymers to double network structure. These gels can be applied not only in medical use but also industrial devices. Smart gels with high mechanical strength are expected to contribute to the development of the field of membrane.View full abstractDownload PDF (764K) -
Ryo Yoshida2006 Volume 31 Issue 6 Pages 307-312
Published: 2006
Released on J-STAGE: June 19, 2015
JOURNAL OPEN ACCESSStimuli-responsive polymers and their application to biomaterials are widely studied. On the other hand, as a novel biomimetic polymer, we have been studying the polymer with an autonomous self-oscillating function by utilizing oscillating chemical reactions. So far, we succeeded in developing a novel self-oscillating polymer and gels by utilizing the Belousov-Zhabotinsky (BZ) reaction. The self-oscillating polymer is composed of poly(N-isopropylacrylamide) (PNIPAAm), in which Ru(bpy)3 is incorporated as a catalyst for the BZ reaction. Under the coexistence of the reactants (malonic acid, sodium bromate, and nitric acid), the polymer undergoes spontaneous cyclic solubleinsoluble changes or swelling-deswelling changes (in the case of gel) without any on-off switching of external stimuli. In this review, our recent studies on the self-oscillating polymer and the design of functional material systems using the polymer are summarized.View full abstractDownload PDF (860K) -
Daisuke Matsukuma, Takao Aoyagi2006 Volume 31 Issue 6 Pages 313-318
Published: 2006
Released on J-STAGE: June 19, 2015
JOURNAL OPEN ACCESSThe macro- or nanometer-ordered modification of material surfaces has attracted much attention in the material sciences, because this method is very practical for fabricating functional material surfaces without sacrificing the physical properties of the materials. To achieve this purpose, the physical or chemical methods, as well as their combination, have been extensively studied. As one of the techniques which build the functional surface, preparation of thin films using polymer gels is mentioned. Polymer gels are soft materials that swell as they absorb large amounts of solvents. These unique materials have applications in both technological and biomedical fields. From a biomedical or biotechnological point of view, the surfaces of gels proffer the potential to create bio-inert (e.g. nonactivated/non-adhesive biomolecules) devices due to their water-swollen structures, which are similar to bio-interfaces such as proteins, cells, and tissues. In particular, the stimuli-responsive gels, which undergo volume phase transitions in response to physical or chemical stimuli in the outer environment, are very interesting materials. These intelligent materials are quite suitable for designing devices such as separation, sensing, actuator, and controlled drug release. Accordingly, it is potentially valuable to fabricate material surfaces composed of stimuli-responsive thin gel films with a nanometer-ordered. This paper focuses on stimuli-responsive thin gel films and a report and usefulness of the recent years about that are reported.View full abstractDownload PDF (649K) -
Ryojiro Tominaga, Takatoshi Kinoshita2006 Volume 31 Issue 6 Pages 319-324
Published: 2006
Released on J-STAGE: June 19, 2015
JOURNAL OPEN ACCESSInterference color is well known as one of the systems to display various colors. By using this system, we tried to develop novel method for the brief estimation of molecular sorption and diffusion in polymer thin-film. We prepared polymer thin-film (polystyrene and polyvinyl alcohol) on the silicon substrate by spin-coat method and dipping method. Reflected visible light at air/polymer and polymer/silicon are interfered each other, and prepared thin-film showed various colors depending on its thickness and refractive index. By the sorption of various small molecules, polymer thin-films swelled and its interference color changed drastically. Degrees of changes in thickness and refractive index of polymer thin-film are able to be estimated by the degree of interference color changes and Bragg’s law and Snell’s law. An almost linear relation between thickness changes in polymer thin-film and solubility parameter was observed by the reflective VIS spectrum measurements of prepared polymer thin-films under various solvent vapors. By this simple method, molecular sorption and diffusion behavior in polymer thin-film could be visualized. This system will give anew brief method for the estimation of polymer - penetrant affinity.View full abstractDownload PDF (875K)
Original Contribution
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Kazuho Nakamura, Wakako Hirayama, Tadashi Nittami, Kanji Matsumoto2006 Volume 31 Issue 6 Pages 325-331
Published: 2006
Released on J-STAGE: June 19, 2015
JOURNAL OPEN ACCESSElectric conductivity (λ) dependency of streaming potential (SP) was measured to estimate the pore size and the surface charge density of the commercial ultrafiltration (UF) membranes having different nominal molecular weight cut-off (NMWCO). At the same λ value the absolute value of SP decreased with the decrease in NMWCO in the range of λ＞1×10–2 S/m. The pore size and surface charge density of UF membrane could be determined by the analysis of λ dependence of streaming potential in the range of λ＞1×10–2 S/m applying a mathematical equation of space charge model. In order to obtain the relation between two pore sizes estimated by SP measurement and the actual separation performance of UF membrane, the MWCO of the UF membrane was measured with 0.03wt% PEG solution. The pore size estimated by SP measurement showed a good linear relation with the Stokes diameter of PEG which has the molecular weight corresponding to MWCO of UF membrane tested. These observations mean the pore size estimated by SP measurement is correlated with the separation performance of UF membrane.View full abstractDownload PDF (709K) -
Shigeyuki Uemiya, Yutaka Makino, Ikumi Miyazaki, Hiroyuki Kawamura, Ry ...2006 Volume 31 Issue 6 Pages 332-336
Published: 2006
Released on J-STAGE: June 19, 2015
JOURNAL OPEN ACCESSA supported thin palladium membrane was fabricated using electroplating coexisting with supercritical carbon dioxide, named supercritical electroplating. In this unique electroplating, immediate dissolution of hydrogen formed via water electrolysis into supercritical carbon dioxide as well as fabrication of a dense metallic film consisting of nano-size crystals will be expected by dispersion of conductive plating solution into inconductive supercritical carbon dioxide. Commercially available palladium plating baths, however, cannot be applied to supercritical electroplating aqueous solution with acidic property, because they were developed to extend the service life by the formation of stable palladium complex in ammonium aqueous solution with basic property. In this study, a new bath composed of PdCl2, KBr, KNO2, H3BO3, Glycine and surfactant was developed for the supercritical palladium plating. As a result, a defect-free palladium film could be fabricated on a porous conductive support.View full abstractDownload PDF (718K)
Products Spotlight
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Tomotaka Hashimoto, Yoshihiko Mori2006 Volume 31 Issue 6 Pages 337-340
Published: 2006
Released on J-STAGE: June 19, 2015
JOURNAL OPEN ACCESSAsahi-kasei Chemicals developed new type hollow fiber module for Membrane Bio-reactor. It has many features for membrane, module structure, and aeration system. Membrane material is PVDF, and its advantages are physical strength and chemical durability. Module structure is cylindrical shape which has many advantages for increasing hollow fiber accumulation, reduction of aeration volume for module, and handling ability. However it had been thought that cylindrical structure had a defect that activated sludge tends to accumulate among hollow fibers and block membrane surface. We could solve this defect by hollow fiber alignment at upper part of module. By this improvement, aeration volume for module and foot print of module decreases drastically.View full abstractDownload PDF (739K)
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