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A polysilsesquioxane-based organic-inorganic hybrid membrane was prepared and applied as a proton-conducting membrane for fuel cells. A membrane of a random copolymer of ethyl 4-(2-methyl-3-triethoxysilylpropoxy)benzenesulfonate and triethoxy(methyl)silane showed proton conductivity of 2.0 × 10−5 to 1.1 × 10−3 S cm−1 at room temperature. A membrane of a block copolymer of poly(3-(4-ethoxysulfonylphenoxy)-2-methylpropyl)silsesquioxane (SPES) and polymethylsilsesquioxane showed proton conductivity of 2.5 × 10−3 S cm−1. The mixture of SPES and poly(vinyl alcohol), poly(ethylene oxide), or polyoctahedralpolysilsesquioxane showed proton conductivity of 2.7 × 10−3, 1.5x10−3 or 2.5 × 10−3 S cm−1, respectively. The open-circuit voltage of the SPES membrane was 0.92 V.
Orientation dynamics of small additive molecules in polymeric films during hot-stretching was investigated by using birefringence analysis and polarized Fourier-transfer infrared (FT-IR) spectroscopy. Birefringence data indicated parallel orientation of the small molecules to main chain of the matrix polymer. Furthermore, polarized FT-IR spectra demonstrated that the ratio of orientation functions of rigid and flexible portions in hexa-methylene naphthalate oligomer showed temperature dependence. The result suggests that the small molecules exhibit two-step orientation in the matrix polymer during stretching.
HEC (or HMHEC) gel swells due to increasing SDS concentration, while the cooperative diffusion becomes faster. This indicates that the HEC (or HMHEC) gel can swell until the osmotic pressure equals the modulus when the charge effect dominates over the effect of configurational entropy for uncharged gels interacting with charged surfactants.
The critical molecular weight (Mc), at which the entanglement effect of the PMMA chain occurs is ~3 × 104. When the PMMA molecular weight in the hybrid suspension and film is such that Mc < Mw, such formation of molecular chain entanglements acts as a driving force for the agglomeration of SiO2 particles. In cases in which the PMMA molecular weight in the hybrid suspension and film is such that Mw< Mc, because no effective entanglements are formed, there is no driving force for the agglomeration of the SiO2 nanoparticles.
We patterned a gold coating on a glass slide to be an interdigitated array (IDA) pattern using spontaneous pattern formation as a key step. First, gold was sputter deposited onto a strip of poly(dimethylsiloxane) (PDMS). Because the strip was heated during the deposition, the gold film wrinkled. Next, a glass strip was placed on the PDMS strip and gold was deposited again. Wrinkles with an IDA pattern were spontaneously formed. The obtained wrinkles were used to pattern a gold coating.
A polymer surface was modified by dip coating a mixture of three kinds of polymers: methacrylate-based terpolymers containing both perfluoroalkyl (Rf) groups and poly(ethylene oxide) (PEO) as side chains, vinylidenefluoride-tetrafluoroethylene copolymer (CH2CF2)80(CF2CF2)20, and poly(methyl methacrylate) (PMMA). These modified surfaces showed resistance to nonspecific protein adsorption, antithrombogenicity and resistance to cell adhesion due to surface-segregated PEO chains. We also succeeded in covalent conjugation of biotin with the termini of PEO chains and demonstrated the immobilization of streptavidin on the dip-coated surface.
Applications of l-Glu molecularly imprinted cellulose membranes to chiral separation were studied. LiCl, which was adopted to dissolve cellulose into solvent, N,N-dimethylactamide (DMAc), worked well as a print molecule to construct recognition sites toward Li+ (or LiCl). The chiral separation ability was greatly dependent on LiCl. The permselectivity was increased with the LiCl concentration and asymptotically reached the maximum value at higher LiCl concentration region. The affinity constants between LiCl and LiCl recognition sites in both control and l-Glu molecularly imprinted membranes were determined to be 65 mol−1 dm3.
Effects of ligand used for fabricating palladium (Pd)-incorporated porous polymer composites were examined on their catalytic performances (efficiency, recyclability and Pd-leaching behavior). The composites fabricated with poly(amidoamine) (PAMAM) dendrimers (Gn, n≥1) as ligand were proved to have a function that was potentially applicable as sustainable heterogeneous catalysts.
For the synthesis of a ladder polyamide, 4,6-diaminoisophthalic acid-type monomers were synthesized and their polymerization was studied. Although the polymerization of the A2- and B2-type monomers with a base afforded small molecular weight-products, the polymerization of the AB-type monomer gave higher molecular weight-products. Analysis of the products by means of matrix-assisted laser desorption ionization time-of-flight mass spectrometry revealed that they were composed of polymers and oligomers with linear and cyclic structure.
