Thermomechanical analysis of a polymer dispersed liquid crystal containing a thermoplastic elastomer

Bulk samples of polymer dispersed liquid crystals (PDLCs) containing polystyrene (PS) and a thermoelastic elastomer as polymer matrices, have been prepared by a thermally-induced phase separation method. Thermomechanical analysis measurements revealed that the PDLC containing the thermoplastic elastomer possessed rubber-like elasticity even in the mesomorphic temperature range of the LC while the PDLC based on PS showed plastic deformation during the measurement.     

The effect of bath pH on electrodeposition and corrosion properties of ternary Fe-W-Zn alloy platings

Journal of Solid State Electrochemistry - As a new trial to improve the corrosion resistance of the Fe-W alloy platings, Fe-W alloys incorporating a small amount of Zn, namely novel ternary Fe-W-Zn...     

Measurement of the change in partial molar volume during electrode reaction by gravity electrode—II. Examination of the accuracy of the measurement

The reliability of the measurement of the change in partial molar volume between product and reactant ions measured by gravity electrode (GE) was examined by the thermodynamic measurement of pycnometer (PM). Since the PM method requires an experimental equation of the apparent molar volume to calculate the partial molar volumes of the individual ions, the most suitable experimental equation must be first determined. As a test reaction for the experiment, oxidation of ferrocyanide (FERO) ion to ferricyanide (FERI) ion was adopted. After fitting several experimental equations to the data of the apparent molar volumes by the PM method, the calculated changes in the partial molar volume were compared with the data of the GM method. Then, it is concluded that the polynomial with a degree of 3 of the logarithm of the molality of the FERO ion suggests the most suitable equation. As a result, the reliability of the GE method was also experimentally validated.     

Intense fluorescence-inducing amphiphile in cationic dyes and its applicability

An anionic amphiphile has been found to form extremely hydrophobic sites in water and specifically incorporate stilbazolium-based compact hemicyanine dyes as monomeric species, resulting in induction of intense fluorescence emission.     

Ruthenium-catalyzed asymmetric hydrogenation of N-boc-indoles

Highly enantioselective hydrogenation of various N-Boc-indoles proceeded successfully in the presence of the ruthenium complex generated from an appropriate ruthenium precursor and a trans-chelate chiral bisphosphine PhTRAP. Various 2- or 3-substituted indoles were converted into chiral indolines with high enantiomeric excesses (up to 95% ee). The PhTRAP-ruthenium catalyst was able to promote the hydrogenation of 2,3-dimethylindoles, giving cis-2,3-dimethylindolines with 72% ee.     

Porogen approach for the fabrication of plasma-polymerized nanoporous polysiloxane films

Nanoporous polysiloxane films were fabricated by plasma polymerization of hexamethyldisiloxane mixed with cyclohexane under different conditions. The pores were generated through the elimination of carbonaceous aggregates (porogen) by annealing at 600 degrees C. Results of spectroscopic ellipsometry, Fourier transform infrared spectroscopy, and positron annihilation lifetime spectroscopy suggest that not only film porosity but also average pore size depends on the amount of the decomposable porogen. The pore size was controllable in a range between 0.6 and 1.0 nm in radius by proper selection of the substrate temperature and precursor composition.     

Permeability control of metal ions using temperature- and pH-sensitive gel membranes

Temperature- and pH-sensitive copolymer gels were synthesized by the simultaneously occurring radiation-induced polymerization and self-bridging of acryloyl- -proline methyl ester (A-ProOMe) with acrylic acid (AAc) in aqueous solutions. The gel swelling behavior and the metal permeation characteristic of its gel membrane were investigated with regard to very slight changes of temperature and pH. The pH threshold of the swelling of a copoly(A-ProOMe/AAc, 70/30 mol%) gel in the range of 5–30°C lay in the region between pH 4.0 and 5.0. The permeability results of metal ions showed that at 40°C the gel membrane blocks the permeation of lithium (Li) and cesium (Cs) ions at pH values lower than 4.75 and 4.60, respectively. The permselectivity (P_Li/Cs value) of the two metal ions at 30°C was also studied and, as a result, its value was obtained to be 1.33 at pH 4.65 and 30°C. This permeation study indicates that the selective metal separation of copoly(A-ProOMe/AAc) gel membranes can be controlled by changing temperature and pH values.     

Simultaneous detection of monohydroxybenzo[a]pyrene positional isomers by reversed-phase liquid chromatography coupled to electrospray ionization mass spectrometry

A liquid chromatographic (LC) method has been developed for the separation of 11 monohydroxybenzo[a]pyrenes (OH BaPs) positional isomers, and for their detection using electrospray ionization mass spectrometry (ESI-MS). All OH BaPs isomers were separated on an octadecylsilyl (C(18))-bonded amorphous organosilica column utilizing gradient elution with acetonitrile-water and triethylamine (TEA) at pH 11.0 and determined by MS, except 2- and 8-OH BaPs which were coeluted. The lower detection limits were in the range from 1.6 micro g/L for 12-OH BaP to 12 micro g/L for 5-OH BaP without any sample enrichment. The relative standard deviations of area response were in the range from 1.8% (9-OH BaP) to 4.9% (12-OH BaP) except for 9.4% (7-OH BaP). The developed method was successfully applied to incubation mixtures of BaP and CYP1A1/epoxide hydrolase. This method identified 1-, 3- and 9-OH BaPs as the major metabolites, and 2- (and/or 8-) and 12-OH BaPs as the minor metabolites in the incubation mixture.     

Highly enantioselective synthesis of chiral 3-substituted indolines by catalytic asymmetric hydrogenation of indoles

[reaction: see text] N-Tosyl 3-substituted indoles were hydrogenated with high enantioselectivities (95-98% ee) by use of a trans-chelating chiral bisphosphine, (S,S)-(R,R)-PhTRAP ligand. The chiral catalyst, which was generated in situ from [Rh(nbd)(2)]SbF(6), PhTRAP, and Cs(2)CO(3), is useful for enantioselectively synthesizing a range of diverse optically active indolines possessing a chiral carbon at the 3-position.