The epoxidation reaction of propylene and hydrogen peroxide with zeolite catalyst containing titaniumsilicalite (TS-1)has been studied, and the reaction in the mixed solvent of water/methanol has been discussed. It is...The epoxidation reaction of propylene and hydrogen peroxide with zeolite catalyst containing titaniumsilicalite (TS-1)has been studied, and the reaction in the mixed solvent of water/methanol has been discussed. It is shown that the selective of epoxidation propylene decreases while the selective of propylene glycol increases, when the water content increases in the mixed solvent of methanol/water.展开更多
Catechinone hair dyestuff was produced chemically from (+)-catechin by the oxidation with O2 in basic water/alcohol mixed solution. The effects of reaction conditions such as basicity, sorts of added base, temperature...Catechinone hair dyestuff was produced chemically from (+)-catechin by the oxidation with O2 in basic water/alcohol mixed solution. The effects of reaction conditions such as basicity, sorts of added base, temperature, alcohol molar fraction of solvent and sorts of added alcohols on the catechinone formation were studied in order to increase the efficiency of the dyestuff production. The amount of obtained catechinone increases with increasing basicity of the reaction solution. The dyestuff is obtained by adding monoethanol amine, diethanol amine, triethanol amine, l-arginine, Na2CO3, K2CO3, Na3PO4 or NaOH into the solution as a base and the most preferable base is monoethanol amine. The optimum temperature for the production in water/ethanol solution is 30°C. It was found that water-soluble alcohols such as methanol, ethanol, 2-propanol, 1-propanol and tert-butyl alcohol are available for preparing the dyestuff. The optimum alcohol molar fraction of the mixed solvent used for the dye formation is 0.45 for methanol, 0.25 for ethanol and 0.20 for 2-propanol, 0.15 for 1-propanol and 0.10 for tert-butyl alcohol. The amount of the obtained dyestuff reaches a maximum at 1) 0.35 and 0.59, 2) 0.35 or 3) 0.35 mol·kg¨1 of the concentration of (+)-catechin for the 1) water/methanol, 2) water/ethanol or 3) water/1-propanol system, respectively.展开更多
Three kinds of amphiphilic PMADAB gels were prepared through radiation-induced polymerization and crosslinking of methacryloxyethyl dimethylalkane ammonium bromide(MADAB) with different alkyl side chains(butyl,octyl a...Three kinds of amphiphilic PMADAB gels were prepared through radiation-induced polymerization and crosslinking of methacryloxyethyl dimethylalkane ammonium bromide(MADAB) with different alkyl side chains(butyl,octyl and dodecyl).The length of alkyl side chains had significant influence on swelling behavior of the PMADAB gels in alcohol/water solvent.Equilibrium swelling degree(EDS) of PMBDAB(butyl) gel in water was ca.160 and decreased with increasing alcohol content(x),whereas EDS of PMODAB(octyl)and PMDDDAB(dodecyl) gels showed a convex-upward function of x,i.e.,these two gels barely swelled in pure water and swelled with increasing x and then shrank gradually.This phenomenon was explained by the hydrophobic association of long alkyl chains and a cosolvency effect of PMADAB in alcohol and water.The swelling behavior of PMADAB gels in methanol,ethanol and isopropanol were similar,and their EDS are related with the dielectric constant of alcohol solvents.The results suggest that PMADAB gels may be potential absorbents for various kinds of alcohols.展开更多
Densities of sodium chlorobenzoate( o , m , p ) were measured in solutions up to 80 weight percent dimethylformamide(DMF) at 298 15 K with an oscillating tube densimeter. From these densities, apparent molar v...Densities of sodium chlorobenzoate( o , m , p ) were measured in solutions up to 80 weight percent dimethylformamide(DMF) at 298 15 K with an oscillating tube densimeter. From these densities, apparent molar volumes of sodium chlorobenzoate in DMF H 2O mixtures were calculated, and partial molar volumes at infinite dilution were evaluated. Substituent and solvent effects on transfer volumes of each isomer from water to DMF H 2O mixed solvents were obtained. The results are explained in terms of solvent structure and solute solvent interaction.展开更多
The influence of solvent and the rate of addition of water on the characteristics of alumina-zirconia powders obtained by sol-gel method were investigated. The Al2O3-ZrO2 powders (1:1 molar ratio) were prepared using ...The influence of solvent and the rate of addition of water on the characteristics of alumina-zirconia powders obtained by sol-gel method were investigated. The Al2O3-ZrO2 powders (1:1 molar ratio) were prepared using aluminum tri-sec-butoxide and zirconium n-propoxide as precursors. Ethanol (EtOH), isopropanol (iPrOH) and isobutanol (iBuOH) were used as solvents. The Al2O3-ZrO2 powders were characterized by nitrogen physisorption (SBET), Fourier transformed infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Prepared oxides calcined at 700℃ showed high specific surface area (200 - 240 m2/g). Obtained results suggest that the homogeneity of the mixed oxides is favored by using a water addition rate of 0.06 and 0.10 mL/min with ethanol as solvent.展开更多
文摘The epoxidation reaction of propylene and hydrogen peroxide with zeolite catalyst containing titaniumsilicalite (TS-1)has been studied, and the reaction in the mixed solvent of water/methanol has been discussed. It is shown that the selective of epoxidation propylene decreases while the selective of propylene glycol increases, when the water content increases in the mixed solvent of methanol/water.
文摘Catechinone hair dyestuff was produced chemically from (+)-catechin by the oxidation with O2 in basic water/alcohol mixed solution. The effects of reaction conditions such as basicity, sorts of added base, temperature, alcohol molar fraction of solvent and sorts of added alcohols on the catechinone formation were studied in order to increase the efficiency of the dyestuff production. The amount of obtained catechinone increases with increasing basicity of the reaction solution. The dyestuff is obtained by adding monoethanol amine, diethanol amine, triethanol amine, l-arginine, Na2CO3, K2CO3, Na3PO4 or NaOH into the solution as a base and the most preferable base is monoethanol amine. The optimum temperature for the production in water/ethanol solution is 30°C. It was found that water-soluble alcohols such as methanol, ethanol, 2-propanol, 1-propanol and tert-butyl alcohol are available for preparing the dyestuff. The optimum alcohol molar fraction of the mixed solvent used for the dye formation is 0.45 for methanol, 0.25 for ethanol and 0.20 for 2-propanol, 0.15 for 1-propanol and 0.10 for tert-butyl alcohol. The amount of the obtained dyestuff reaches a maximum at 1) 0.35 and 0.59, 2) 0.35 or 3) 0.35 mol·kg¨1 of the concentration of (+)-catechin for the 1) water/methanol, 2) water/ethanol or 3) water/1-propanol system, respectively.
基金Supported by the China Postdoctoral Science Foundation(No.2012M520164)the Fundamental Research Funds for the Central Universities(No.FRF-TP-13-008A)
文摘Three kinds of amphiphilic PMADAB gels were prepared through radiation-induced polymerization and crosslinking of methacryloxyethyl dimethylalkane ammonium bromide(MADAB) with different alkyl side chains(butyl,octyl and dodecyl).The length of alkyl side chains had significant influence on swelling behavior of the PMADAB gels in alcohol/water solvent.Equilibrium swelling degree(EDS) of PMBDAB(butyl) gel in water was ca.160 and decreased with increasing alcohol content(x),whereas EDS of PMODAB(octyl)and PMDDDAB(dodecyl) gels showed a convex-upward function of x,i.e.,these two gels barely swelled in pure water and swelled with increasing x and then shrank gradually.This phenomenon was explained by the hydrophobic association of long alkyl chains and a cosolvency effect of PMADAB in alcohol and water.The swelling behavior of PMADAB gels in methanol,ethanol and isopropanol were similar,and their EDS are related with the dielectric constant of alcohol solvents.The results suggest that PMADAB gels may be potential absorbents for various kinds of alcohols.
文摘Densities of sodium chlorobenzoate( o , m , p ) were measured in solutions up to 80 weight percent dimethylformamide(DMF) at 298 15 K with an oscillating tube densimeter. From these densities, apparent molar volumes of sodium chlorobenzoate in DMF H 2O mixtures were calculated, and partial molar volumes at infinite dilution were evaluated. Substituent and solvent effects on transfer volumes of each isomer from water to DMF H 2O mixed solvents were obtained. The results are explained in terms of solvent structure and solute solvent interaction.
文摘The influence of solvent and the rate of addition of water on the characteristics of alumina-zirconia powders obtained by sol-gel method were investigated. The Al2O3-ZrO2 powders (1:1 molar ratio) were prepared using aluminum tri-sec-butoxide and zirconium n-propoxide as precursors. Ethanol (EtOH), isopropanol (iPrOH) and isobutanol (iBuOH) were used as solvents. The Al2O3-ZrO2 powders were characterized by nitrogen physisorption (SBET), Fourier transformed infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Prepared oxides calcined at 700℃ showed high specific surface area (200 - 240 m2/g). Obtained results suggest that the homogeneity of the mixed oxides is favored by using a water addition rate of 0.06 and 0.10 mL/min with ethanol as solvent.
