Advanced Materials Research Vols. 602-604

Abstract: The adsorption of methane (CH₄) molecule on the pristine and Al-doped (4, 8) graphene was investigated via the first-principles calculations. The results demonstrated that, in comparison to the adsorption of a CH₄ molecule on the pristine graphene sheet, a relatively stronger adsorption was observed between the CH₄ molecule and Al-doped graphene with a shorter adsorption distance, larger binding energy and more charge-transfer from the graphene surface to the CH₄ molecule. Therefore, the Al-doped graphene can be expected to be a novel sensor for the detection of CH₄ molecules in future applications.

Abstract: Sampled with the pigments extracted from Chinese chestnut shell by alkali solution, chromaticity with protein and starch and chromaticness and red index are related to. The characteristics were compared with that of the standard caramel pigment. Methods were used by spectrometer and colorimeter. Compared with caramel pigments, better chromaticity and stability with starch and protein, lower chromacticness and higher red index of pigments in shell were shown.

Abstract: In this paper, a novel, fast, and accurate method to predict the energy bandgap Eg in Ga_xIn_1-xAs_yP_1-y quaternary compounds by using fuzzy theory and neural network is proposed. It has been developed to analyze the energy bandgap due to the adjustable ratios x and y of quaternary compounds. The prediction results are compared with experimental data obtained from actual devices. A good agreement (error xIn_1-xAs_yP_1-y quaternary compounds.

Abstract: The photoabsorption spectra of linear double Na atomic chains with different lengths and inter-chain spacings are investigated using the time-dependent density functional theory (TDDFT) in the frequency domain. The formation and development of the collective resonances in the spectra are studied in terms of the spacing and length. With the decreasing spacing, the enhanced coupling between the chains lead to the emergence of extra peaks. For the well coupled double chains, the excitations show a single longitudinal mode but twin bimodal structure for the transverse modes. Our calculation reveals the formation and evolution of plasmon excitations in atomic nanostructures.

Abstract: The extraction equilibrium of four rare earth ions (REn+, n = 3 or 4) was investigated in ionic liquid (IL) extraction system using 1-butyl-3-methyl-imidazolium hexafluorophosphate ([Bmim]PF6) ionic liquid as extraction solvent and 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (HPMBP, HP) as extractant. The extraction percentage could be higher than 99%. The extracted species in the REn+-[Bmim]PF6-HP system was neutral REPn (n = 3 or 4) and complete recovery of REn+ extracted into [Bmim]PF6 can be achieved using diluent HCl as stripping agent. [Bmim]PF6 can be recycled in the experiment. The extraction equilibrium constants and the pH1/2 values of four REs and their separation factors between adjacent rare earths were estimated and comparatively studied.

Abstract: An unsymmetrical diarylethene derivative was synthesized, and its photochromic properties and fluorescence switch were investigated in detail. The results showed that this compound exhibited reversible photochromism, undergoing reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light both in solution and in PMMA film, and its absorption maxima were observed at 599 nm in hexane and at 609 nm in PMMA amorphous film, respectively, upon irradiation with 297 nm UV light. The fluorescence intensity of diarylethene decreased dramatically along with the photochromism from open-ring isomer to closed-ring isomer upon irradiation with 297 nm light in PMMA. In hexane solution, the open-ring isomer of the diarylethene 1 exhibited relatively strong fluorescence at 419 nm when excited at 309 nm. The fluorescence intensity is highest at the concentration of 5.0×10^-5 mol/L when excited at 309 nm.

Abstract: A novel unsymmetrical photochromic diarylethene 1-(2-methyl-3-benzothienyl)-2-{2-n-butyl-5-[2-(1,3-dioxolane)]-3-thienyl}perfluorocyclopentene(1O) was synthesized, and its photochromic, fluorescent and optical strorage properties were investigated. The compounds 1O exhibited remarkable photochromism both in solution and in PMMA film, and the results showed that the cyclization/cycloreversion process of the compound was determined to be the zeroth/first order reaction. In addition, this new photochromic system also exhibited remarkable optical storage character.

Abstract: A new unsymmetrical photochromic diarylethene 1-(2-methyl-benzofuran-3-yl)-2-(2-n-butyl-5-(1,3-dithiolane)-thiophene-3-yl) perfluoroncyclopentene (1o), was synthesized and its optoelectronic properties, such as photochromism in solution as well as in poly-methylmethacrylate (PMMA) amorphous films, and the fluorescence spectra of diarylethene 1a was investigated. Using diarylethene 1c/PMMA film as recording medium and a linearly polarized 633 nm laser diode for recording and readout, polarization multiplexed image recording can be carried out in this film, which illustrated that the diarylethene can be potentially used as holographic optical recording medium.

Abstract: A new photochromic diarylethene bearing thiophene and naphtyl unit 1-(2-methyl-1-naphthyl)-2-[2-methyl-5-(2-cyanophenyl)-3-thienyl]perfluorocyclopentene (1o), was synthesized and its phtochromic, fluorescence, kinetics and optical recording properties were investigated in detail. This compound exhibited remarkable photochromism, changing from colorless to red after irradiation with 297 nm UV light both in solution and in PMMA film. Finally, using diarylethene 1c as recording medium, polarization optical recording was carried out successfully.

Abstract: Severe strength loss is the most important problem for denim wrinkle-setting resin finishing. N,N-dimethylol 4,5-dihydroxy- ethylene urea (DMDHEU) resin、composite catalyst, baking time and temperature were used as four important factors in experimental design by central lab. The significant influence and the optimum condition achieved by analysis four factors and regression analysis. In contrast to traditional catalyst magnesium chloride, under optimum condition employed by composite catalyst 20.61(g/L), resin 143.08(g/L), baked at 129.4°C for 18.0 min, the strength loss of treated fabric reduced by more than 12%.