A new simple, rapid and sensitive spectrophotometric method for the determination of chlordiazepoxide is described, based on the reaction with 2,4-dinitrophenol in water medium, apparently by a charge-transfer mechani...A new simple, rapid and sensitive spectrophotometric method for the determination of chlordiazepoxide is described, based on the reaction with 2,4-dinitrophenol in water medium, apparently by a charge-transfer mechanism, to yield 1:1 complex with maximum absorption at 444 nm. Optimum experimental conditions for the determination have been studied. The linear calibration range, apparent molar absorptivity and relative standard deviation are 2.8~96.0 mgmL-1, 1.48103 and 0.32%, respectively. The method is accurate and has been successfully applied to the determination of chlordiazpoxide in tablets. The results are in good agreement with those obtained with the official method.展开更多
Poly(methacrylic acid co-poloxamer) hydrogel networks were synthesized by free radical solution polymerization and their equilibrium swelling and solute permeation properties were characterized. These gels exhibited p...Poly(methacrylic acid co-poloxamer) hydrogel networks were synthesized by free radical solution polymerization and their equilibrium swelling and solute permeation properties were characterized. These gels exhibited pH dependant swelling and solute diffusivity due to the formation or disruption of hydrogen bonded complexation between methacrylic acid (MAA) and etheric (EO). In neutral and basic conditions (above the swelling transition pH), the copolymer swelling was greatly higher than acid condition. In complexed hydrogels, the diffusion coefficients of vitamin B12 (VB12) were in the range of 10-10 to 10-7 cm2s-1; While in uncomplexed hydrogels, the values were about 210-6 cm2s-1. The comonomer composition and synthesis conditions have great effect on the structure, and thereby, swelling and solute diffusion characteristics of the resultant hydrogels. For the copolymers with composition of less than or more than 1:1 MAA/EO molar ratio, the plot of lnD vs 1/H-1 followed two different linear equations of 慺ree volume theory? respectively.展开更多
A new electrochemical reactor with rotating cylindrical electrodes was designed and used to increase the regeneration efficiency of chelated iron desulfurization solution.The influence of operating parameters,such as ...A new electrochemical reactor with rotating cylindrical electrodes was designed and used to increase the regeneration efficiency of chelated iron desulfurization solution.The influence of operating parameters,such as the rotation speed of electrode,voltage,and inlet air and liquid flow rates,on the regeneration rate was investigated.Compared with the traditional tank-type reactor,the regeneration rate with the new electrochemical reactor was increased significantly.Under the optimum conditions,the regeneration rate was increased from 45.3%to 84.8%.Experimental results of continuous operation indicated that the new electrochemical regeneration method had some merits including higher regeneration efficiency,smaller equipment size and good stability in operation.展开更多
Encapsulation of DASP （4-[4-（dimethylamino）styryl]-l-octylpyridinium bromide） with amylose, and conformational transitions of amylose upon complexation with the dyes were investigated using UV-vis, fluorescence an...Encapsulation of DASP （4-[4-（dimethylamino）styryl]-l-octylpyridinium bromide） with amylose, and conformational transitions of amylose upon complexation with the dyes were investigated using UV-vis, fluorescence and two-photon absorption properties in various Dimethyl Sulfoxide （ DMSO）/H20 mixtures. Encapsulation of the dye was achieved by dilution of DMSO stock solutions of the chromophores （1 x 10^-3 M） and amylose （1 x 10^-1 M） with DMSO, followed by a dropwise addition of H20 with continuous stirring at room temperature. At less than 40% aqueous DMSO solutions, the chromophores had a stable encapsulation with amylose and showed over 100 times the fluorescence intensity of non-encapsulated chromophores. Both of the dye solution with and without amylose also exhibit 2PA （two-photon absorption）, as determined by nonlinear absorption measurements using 10 ns laser pulses at 800 nm. The respective values of two-photon cross-sections are 13.3 x 10.20 for encapsulated dye solution and 2.53 x 10.20 cma/GW for non encapsulated dye solution. The data clearly indicate that the contribution of the encapsulated dye dominates the two-photon absorption cross-section of the non encapsulated dye at 800 nm.展开更多
Optimization of factors influencing the experiments on reactions involving 8 different chelating agents and soluble Fe(III)/Fe(II) salts was carried out to yield chelated iron complexes. A combination of optimized inf...Optimization of factors influencing the experiments on reactions involving 8 different chelating agents and soluble Fe(III)/Fe(II) salts was carried out to yield chelated iron complexes. A combination of optimized influencing factors has resulted in a Fe chelating capacity of the iron-based desulfurization solution to be equal to 6.83—13.56 g/L at a redox potential of 0.185—0.3. The desulfurization performance of Fe(III)/Fe(II) chelating agents was investigated on a simulated sulfur-containing industrial gas composed of H2 S and N2 in a cross-flow rotating packed bed. Test results have revealed that the proposed iron-based desulfurization solution showed a sulfur removal efficiency of over 99% along with a Fe chelating capacity exceeding 1.35 g/L. This desulfurization technology which has practical application prospect is currently in the phase of commercial scale-up study.展开更多
Toxic Zn（II） ion imprinted interpenetrating polymer networks were synthesized for the selective sorption of Zn（ll） from aqueous solutions using a biopolymer alginic acid. The polymeric biosorbant was prepared usin...Toxic Zn（II） ion imprinted interpenetrating polymer networks were synthesized for the selective sorption of Zn（ll） from aqueous solutions using a biopolymer alginic acid. The polymeric biosorbant was prepared using Zn（II） ion as template, acrylamide as functional monomer, cross linker NNMBA （N,N＇ Methylene-bis-acrylamide） and potassium persulphate as an initiator. The non-imprinted polymer networks were also prepared without use of the Zn（II） ion. The synthesized interpenetrating networks were characterized by various spectral techniques. Metal ion binding studies were carried out and the factors affecting binding were also optimized. Competitive sorption studies were investigated to determine the selectivity of Zn（II） ion imprinted interpenetrating polymer network. Zinc ion imprinted polymer networks showed good selectivity for the target ion.展开更多
文摘A new simple, rapid and sensitive spectrophotometric method for the determination of chlordiazepoxide is described, based on the reaction with 2,4-dinitrophenol in water medium, apparently by a charge-transfer mechanism, to yield 1:1 complex with maximum absorption at 444 nm. Optimum experimental conditions for the determination have been studied. The linear calibration range, apparent molar absorptivity and relative standard deviation are 2.8~96.0 mgmL-1, 1.48103 and 0.32%, respectively. The method is accurate and has been successfully applied to the determination of chlordiazpoxide in tablets. The results are in good agreement with those obtained with the official method.
文摘Poly(methacrylic acid co-poloxamer) hydrogel networks were synthesized by free radical solution polymerization and their equilibrium swelling and solute permeation properties were characterized. These gels exhibited pH dependant swelling and solute diffusivity due to the formation or disruption of hydrogen bonded complexation between methacrylic acid (MAA) and etheric (EO). In neutral and basic conditions (above the swelling transition pH), the copolymer swelling was greatly higher than acid condition. In complexed hydrogels, the diffusion coefficients of vitamin B12 (VB12) were in the range of 10-10 to 10-7 cm2s-1; While in uncomplexed hydrogels, the values were about 210-6 cm2s-1. The comonomer composition and synthesis conditions have great effect on the structure, and thereby, swelling and solute diffusion characteristics of the resultant hydrogels. For the copolymers with composition of less than or more than 1:1 MAA/EO molar ratio, the plot of lnD vs 1/H-1 followed two different linear equations of 慺ree volume theory? respectively.
基金Supported by the National Natural Science Foundation of China(21376229)the Excellent Innovation Projects of Postgraduates of Shanxi Province(20103084)the Science and Technology Innovation Projects of Shanxi Province Colleges and Universities(2013128)
文摘A new electrochemical reactor with rotating cylindrical electrodes was designed and used to increase the regeneration efficiency of chelated iron desulfurization solution.The influence of operating parameters,such as the rotation speed of electrode,voltage,and inlet air and liquid flow rates,on the regeneration rate was investigated.Compared with the traditional tank-type reactor,the regeneration rate with the new electrochemical reactor was increased significantly.Under the optimum conditions,the regeneration rate was increased from 45.3%to 84.8%.Experimental results of continuous operation indicated that the new electrochemical regeneration method had some merits including higher regeneration efficiency,smaller equipment size and good stability in operation.
文摘Encapsulation of DASP （4-[4-（dimethylamino）styryl]-l-octylpyridinium bromide） with amylose, and conformational transitions of amylose upon complexation with the dyes were investigated using UV-vis, fluorescence and two-photon absorption properties in various Dimethyl Sulfoxide （ DMSO）/H20 mixtures. Encapsulation of the dye was achieved by dilution of DMSO stock solutions of the chromophores （1 x 10^-3 M） and amylose （1 x 10^-1 M） with DMSO, followed by a dropwise addition of H20 with continuous stirring at room temperature. At less than 40% aqueous DMSO solutions, the chromophores had a stable encapsulation with amylose and showed over 100 times the fluorescence intensity of non-encapsulated chromophores. Both of the dye solution with and without amylose also exhibit 2PA （two-photon absorption）, as determined by nonlinear absorption measurements using 10 ns laser pulses at 800 nm. The respective values of two-photon cross-sections are 13.3 x 10.20 for encapsulated dye solution and 2.53 x 10.20 cma/GW for non encapsulated dye solution. The data clearly indicate that the contribution of the encapsulated dye dominates the two-photon absorption cross-section of the non encapsulated dye at 800 nm.
基金financially supported by the Natural Science Fundation of China (No.21376229) the Science and Technology Development Plan of Shanxi Province,China (No.20130321035-02)
文摘Optimization of factors influencing the experiments on reactions involving 8 different chelating agents and soluble Fe(III)/Fe(II) salts was carried out to yield chelated iron complexes. A combination of optimized influencing factors has resulted in a Fe chelating capacity of the iron-based desulfurization solution to be equal to 6.83—13.56 g/L at a redox potential of 0.185—0.3. The desulfurization performance of Fe(III)/Fe(II) chelating agents was investigated on a simulated sulfur-containing industrial gas composed of H2 S and N2 in a cross-flow rotating packed bed. Test results have revealed that the proposed iron-based desulfurization solution showed a sulfur removal efficiency of over 99% along with a Fe chelating capacity exceeding 1.35 g/L. This desulfurization technology which has practical application prospect is currently in the phase of commercial scale-up study.
文摘Toxic Zn（II） ion imprinted interpenetrating polymer networks were synthesized for the selective sorption of Zn（ll） from aqueous solutions using a biopolymer alginic acid. The polymeric biosorbant was prepared using Zn（II） ion as template, acrylamide as functional monomer, cross linker NNMBA （N,N＇ Methylene-bis-acrylamide） and potassium persulphate as an initiator. The non-imprinted polymer networks were also prepared without use of the Zn（II） ion. The synthesized interpenetrating networks were characterized by various spectral techniques. Metal ion binding studies were carried out and the factors affecting binding were also optimized. Competitive sorption studies were investigated to determine the selectivity of Zn（II） ion imprinted interpenetrating polymer network. Zinc ion imprinted polymer networks showed good selectivity for the target ion.
