Pretreatment of sugarcane bagasse by acidified aqueous polyol solutions

Pretreatments of sugarcane bagasse by three high boiling-point polyol solutions were compared in acid-catalysed processes. Pretreatments by ethylene glycol (EG) and propylene glycol solutions containing 1.2 % H₂SO₄ and 10 % water at 130 °C for 30 min removed 89 % lignin from bagasse resulting in a glucan digestibility of 95 % with a cellulase loading of ~20 FPU/g glucan. Pretreatment by glycerol solution under the same conditions removed 57 % lignin with a glucan digestibility of 77 %. Further investigations with EG solutions showed that increases in acid content, pretreatment temperature and time, and decrease in water content improved pretreatment effectiveness. A good linear correlation of glucan digestibility with delignification was observed with R² = 0.984. Bagasse samples pretreated with EG solutions were characterised by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction, which confirmed that improved glucan enzymatic digestibility is mainly due to delignification and defibrillation of bagasse. Pretreatment by acidified EG solutions likely led to the formation of EG-glycosides. Up to 36 % of the total lignin was recovered from pretreatment hydrolysate, which may improve the pretreatment efficiency of recycled EG solution.     

Electrochemical Polymerization of Benzene by use of Aluminum Chloride and Copper(I) Chloride

Electrochemical polymerization of benzene has been carried out in a one-compartment cell using indium-tin oxide conducting glass as a working electrode and Pt mesh as a counterelectrode by the use of a composite electrolyte of aluminum chloride and copper(I) chloride in nitrobenzene. On applying a constant voltage at + 1.8 V vs SCE, a brown and flexible polyparaphenylene (PPP) film was smoothly obtained on the ITO anode surface. The electrical conductivity of the film as grown was 1.9 × 10^?5 S/cm. Aluminum and chlorine atoms were detected in the film from XPS studies, so the film might contain AlCl₄ ^? (and Cl^?) as a dopant. Scanning electron micrographs of the growing side surface of the film prepared at a constant potential of + 1.8 V vs SCE showed a fibrillar morphology. The fibril diameter (～100 nm) was similar to that of a polyaniline film. The PPP film exhibited a spin concentration of 1.0 × 10¹⁹ spins/g, which corresponds to 800 phenylene units per spin. The g-value and the peak-to-peak linewidth were 2.0045 and 7 G, respectively.     

Selective accumulation of harmful compounds by the DNA-inorganic hybrid-immobilized glass bead

Previously, we reported the DNA-inorganic hybrid material including double-stranded DNA by mixing the aqueous DNA solution and silane coupling reagents. Here, we immobilized the DNA-inorganic hybrid material onto the glass bead and prepared the DNA-immobilized glass bead column. The DNA-immobilized glass beads were stable in water and the amount of eluted DNA from the DNA-glass beads did not change for more than 1 week. Additionally, this DNA-immobilized column selectively accumulated the harmful compounds with the planar structure, such as dioxin- and polychlorinated biphenyl (PCB)-derivatives, and these accumulation percentages were 50-70%. Furthermore, the DNA-immobilized glass bead was recycled nine times by the application of ethanol solution and the accumulative ratio was maintained at more than 60% and did not appear to be decreasing. Therefore, these DNA-columns might have a potential for the selective removal and separation of DNA-intercalating molecules and harmful compounds with the planar structure from experimental or industrial drainages.     

Fluorination of fluoro-cyclobutene with high-valency metal fluoride

Fluorinations of 1,4,4-trifluorocyclobutene and 3,3,4,4-tetrafluorocyclobutene using high-valency metal fluorides such as CoF₃, MnF₃, AgF₂, CeF₄ and KCoF₄, and elemental fluorine were examined. In these reactions with CoF₃ and MnF₃, vic-difluorination proceeded mainly. While, 1,4,4-trifluorocyclobutene yielded 3,3,4,4-tetrafluorocyclobutene, and 3,3,4,4-tetrafluorocyclobutene yielded 1,3,3,4,4-pentafluorocyclobutene mainly in the case of AgF₂. The further fluorinated products were increased under severer conditions. Also, the plausible reaction mechanism was suggested.     

Ferrocenylnaphthalene diimide-based electrochemical ribonuclease assay.

Messenger RNA (mRNA) poly(A)+RNA (from mouse kidney) was immobilized on a N-hydroxysuccinimide(NHS)-activated carboxylic acid modified electrode prepared by the treatment of a gold electrode with 3,3'-dithiodipropionic acid, followed by NHS and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC). An electrochemical measurement using this mRNA electrode was carried out in an electrolyte containing ferrocenylnaphthalene diimide (1), and showed an electrochemical signal based on 1 concentrated on immobilized mRNA. After treating this electrode with water containing varied amounts of ribonuclease A (RNase A), the current peak based on 1 decreased with increasing in the amount of RNase A with a linear correlation in the range of 0.2-10 pg of RNase A.     

Synthesis of novel perfluorosulfonamide monomers and their application

The novel perfluorosulfonamide monomers and their preparation methods have been developed. The ternary-copolymer membranes, utilizing the perfluorosulfonamide monomers as the cross-linking site, can be efficiently converted to the cross-linked membranes with the strictly controlled structure. The novel cross-linking method has proved to be effective for the improvement of the mechanical properties at high temperature, while keeping its high proton conductivity.     

Isolation, absolute configuration, and chiral crystallization of optically active seleninic acid

An optically pure seleninic acid was isolated as stable crystals for the first time by chiral crystallization. The relationship between the absolute configurations and the circular dichroism spectra of the enantiomers could be determined by X-ray crystallographic analysis.     

A novel class of materials for ferroelectric liquid crystals containing siloxy chain end groups

Novel liquid crystals containing a siloxy chain as an end tail group instead of an alkyl chain were synthesized. The substitution effects were studied for ferroelectric liquid crystal materials. It was found that the temperature range for the chiral smectic C phase was reduced and shifted to lower temperature in comparison with the analogous alkyl chain derivatives. The crystallinity of the siloxy chain derivatives decreased and cholesteric phases were not observed. The influence of siloxy chains on ferroelectric liquid crystal properties, especially spontaneous polarizations and tilt angles, also greatly depended upon the mesogenic group structure. The X-ray diffraction results showed that the end tail group occupied a larger thickness in the chiral smectic C layer for the siloxy chain derivative than that for the alkyl chain derivative.