Preparation of dithiocarbamatecellulose derivatives and their adsorption properties for trace elements

Tosylcellulose was treated separately with aniline, benzylamine, n-butylamine and piperazine to give four different aminocelluloses which were further treated with carbon disulfide to furnish four dithiocarbamatecelluloses (AND, BZD, BUD and PID). A comparative study was made of their performance as adsorbents for several kinds of metal ions. PID, which has the highest degree of substitution of the dithiocarbamate group of the four derivatives obtained, was investigated for its adsorption behavior towards Ag⁺, As⁵⁺, Cd²⁺, Co²⁺, Cr³⁺, Cr⁶⁺, Cu²⁺, Fe³⁺, Hg²⁺, Mn²⁺, Pb²⁺, Sb⁵⁺; Se⁴⁺, Te⁴⁺ and Zn²⁺. PID showed good adsorption characteristics with relatively large capacities for Ag⁺, Cr⁶⁺, Cu²⁺, Hg²⁺, Pb²⁺ and Se⁴⁺ ranging from 9.5 to 370 mg g^-1 of resin.     

Nanostructured liquid-crystalline Li-ion conductors with high oxidation resistance: molecular design strategy towards safe and high-voltage-operation Li-ion batteries

Nanostructured, uncharged liquid-crystalline (LC) electrolyte molecules having bicyclohexyl and cyclic carbonate moieties have been developed for application in Li-ion batteries as quasi-solid electrolytes, which suppress leakage and combustion. Towards the development of safe and high performance Li-ion batteries, we have designed Li-ion conductive LC materials with high oxidation resistance using density functional theory (DFT) calculation. The DFT calculation suggests that a mesogen with a bicyclohexyl moiety is suitable for the high-oxidation-resistance LC electrolytes compared to a mesogen containing phenylene moieties. A tri(oxyethylene) chain introduced between the cyclic carbonate and the bicyclohexyl moiety in the core part tunes the viscosity and the miscibility with Li salts. The designed Li-ion conductive LC molecules exhibit smectic LC phases over a wide temperature range, and they are miscible with added lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt up to 5 : 5 in molar ratio in their smectic phases. The resulting LC mixtures with LiTFSI show oxidation resistance above 4.0 V vs. Li/Li⁺ in cyclic voltammetry measurements. The enhanced oxidation resistance improves the performance of Li half-cells containing LC electrolytes.

Ion-conductive liquid-crystalline molecules with high-oxidation resistance, which were designed with density functional theory calculation, improved charge–discharge reactions in Li-ion batteries.     

Polarized fluorescence and electroluminescence from rubbing-aligned conjugated polymers and their composites with fluorescent dyes

Polarized fluorescence and optical absorption studies of rubbing-treated poly(2,5-diheptyloxybenzene) and poly (3-alkylthiophene)s (PATs) were carried out with the aim of obtaining polarized electroluminescence (EL). It was revealed that there exists an optimum alkyl chain length in PATs for the effect of rubbing. Polarized EL with a dichroic ratio of 2.6 was observed from a rubbing-aligned PAT-12 film. It was also demonstrated that the rubbing treatment of composite films of PAT and several fluorescent dyes such as 1,4-bis (2-methylstyryl)benzene enabled us to obtain polarized emission from oriented dye molecules. © 1997 John Wiley & Sons, Ltd.     

Quantitative detection and fixation of single and multiple gold nanoparticles on a microfluidic chip by thermal lens microscope.

A detection and fixation method of single and multiple gold nanoparticles on the wall of a microfluidic channel is demonstrated. A thermal lens microscope (TLM) with continuous-wave excitation (wavelength, 532 nm) and probe (wavelength, 670 nm) laser beams was used to realize the sensitive detection of heat generated by light absorption of individual gold nanoparticles (50 nm in diameter); fixation of the individual nanoparticles was realized simultaneously. The fixation mechanism was investigated and attributed to an absorption-based optical force. In addition to single nanoparticle detection, multiple-nanoparticle detection and fixation was demonstrated. An acceleration of fixation was observed when the number of fixed particles was increased. TLM is expected to be a powerful tool for both the quantitative detection and precise fixation of individual nanoparticles.     

A Mössbauer spectrometry study on the phase decomposition of cast duplex stainless steel

Cast CF3M duplex stainless steel having 25% of ferrite in volume fraction was aged at 723 K for time periods up to 10000 h. Phase decomposition of ferrite was investigated by Mössbauer spectroscopy. Ferrite decomposed initially via a spinodal process to finally yield the Fe-rich and the Cr-rich phase. The hyperfine magnetic field distribution obtained from the experimental Mössbauer spectrum was analyzed by assuming trinomial distribution of main constituent atoms Fe, Cr, Ni to determine Cr and Ni content of the Fe-rich phase. Main compositions of the phase were 84 at.% Fe, 11 at.% Cr, 5 at.% Ni.     

Nanopattern formation on Cu(0 0 1) surface coadsorbed with nitrogen and oxygen

Strain-induced nanopatterns formed by the coadsorption of nitrogen and oxygen atoms are studied on the Cu(0 0 1) surface by scanning tunneling microscopy. A square grid pattern similar to that on the N-adsorbed surface appears, and consists of square c(2 × 2) areas with adsorbed N and O atoms when the total density of the adsorbates is around 30% of the Cu atom density on the clean surface. We evaluated the surface strain using a first-principles calculation for a coadsorbed surface and compared it with those on the clean and N-adsorbed surfaces. The strain on the coadsorbed surface is smaller than that of the N-adsorbed surface. The observed size of the square c(2 × 2) area on the coadsorbed surface is larger than that on the N-adsorbed surface with increasing the density of the adsorbates on average as expected by the strain reduction. On the other hand, there is no significant difference in the period of the grid pattern.     

Formulation study for lansoprazole fast-disintegrating tablet. I. Effect of compression on dissolution behavior

Lansoprazole fast-disintegrating tablet (LFDT) is a new patient-friendly formulation of lansoprazole. Since lansoprazole is an antiulcer agent and is unstable under acidic conditions, we have developed LFDT as an orally disintegrating tablet containing enteric-coated microgranules. The effect of compression on dissolution behavior was investigated, as compression affected cleavage and crushing of the enteric layer. To decrease cleavage and crushing of the enteric layer, the effects of the combined ratio of methacrylic acid copolymer dispersion to ethyl acrylate-methyl methacrylate copolymer dispersion and the concentration of triethyl citrate on the dissolution in the acid stage and the dissolution in the buffer stage were evaluated. By adjusting the ratio of methacrylic acid copolymer dispersion to ethyl acrylate-methyl methacrylate copolymer dispersion to 9 : 1 and adding a 20% triethyl citrate concentration, sufficient flexibility of the enteric layer and sufficient stability against compression forces were achieved. Agglomeration of enteric-coated microgranules during the coating process was decreased at the optimized concentration of triethyl citrate and glyceryl monostearate. We compared the absorption properties of LFDT and lansoprazole capsules in dogs. The absorption profiles of LFDT were similar to those of lansoprazole capsules.     

Routine determination of light elements by charged-particle activation analysis

Bombardment conditions, chemical separation, and counting method were examined for routine determination of carbon, nitrogen, and oxygen in various matrices by charged-particle activation analysis with respect to reliability, reproducibility, simplicity, and rapidity. A system was then set up for trustworthy measurement of these elements.     

Transverse electroreflectance of GaSe at the fundamental absorption edge

The transverse electroreflectance of GaSe has been measured near the fundamental edge at 4.2 K. The observed structures have been interpreted in terms of the Franz-Keldysh oscillations, the exciton ground state, the first excited state of exciton, and the phonon replica of the exciton ground state.     

Resonant brillouin scattering by injected acoustic phonons in ZnSe

Measurements are reported on the dispersion curve of the Brillouin scattering cross section of TA phonons in ZnSe by making use of hihigh-intensity phonon flux obtained by transmitting the acoustoelectric domain in CdS. Resonant cancellation and enhancement of the scattering efficiency was observed in the region near the absorption edge at room temperature.