CHEMICAL ENGINEERING JOURNAL
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2014
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IF 4.058
Ming-Xia Wang,Qi-Lei Zhang,Shan-Jing Yao
Mycelial pellets prepared using a marine-derived Penicillium janthinellum sp. strain (P1) were applied as biosorbents to remove dyes from aqueous solutions. Nine different dyes were studied and the effects of pH and salt concentration on the decolorization processes were investigated. The results showed that the mycelial pellet was effective in removing dyes from their water solutions. Moreover, it was found that pH was an important factor of the decolorization process and the best dye removal performance was achieved when pH = 5.0. The adsorption process of the live mycelial pellets was not affected by high salt concentrations. In addition, the mycelial pellets retained 91.3% of the original decolorization activity after five reusing cycles without any desorption treatments. The adsorption isotherms indicated that the biosorption process agreed well with the Langmuir isotherm model with a maximum biosorption capacity of 344.83 mg g(dry) − 1 and the kinetic adsorption results showed that the biosorption process followed a pseudo-second-order kinetic model.
研究领域:
环境微生物学
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环境工程
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生物吸附
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水污染控制
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应用微生物学
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环境化学
✓ 已验证
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
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2016
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IF 2.848
Zhanjing Guo,Xiongmin Liu,Hongmiao Huang,Lingfeng Jiang
The strong acidic cationic exchange fiber (SACEF) was used to adsorb yohimbine from alcoholic solution. Batch experiments were performed to examine the effects of adsorbent dosage, solution pH and temperature in the adsorption process. The thermodynamics and kinetics of adsorption were also analyzed. The optimum yohimbine adsorption onto the SACEF was found at pH = 5 of solution and equilibrium could be attained within 20 min. The equilibrium adsorption data were preferably modeled with the Freundlich isotherm model and the thermodynamic parameters were calculated to be: 11.99 kJ/mol < Δ H < 13.72 kJ/mol, −21.17 kJ/mol < Δ G < −17.87 kJ/mol and 63.18 J/mol K < Δ S < 65.60 J/mol K. The results demonstrated that the adsorption was an endothermic, spontaneous and feasible process of physisorption . Meanwhile, yohimbine adsorption on SACEF fitted well to the pseudo-second-order kinetic model and the adsorption rate was limited by film diffusion. The activation energy Ea was calculated to be 14.39 kJ/mol. Furthermore, the surface morphologies of the SACEF before and after yohimbine adsorption were analyzed by SEM and the adsorption mechanism was discussed by FTIR analysis. SACEF could effectively adsorb yohimbine from alcoholic solution and could be used repeatedly for more than five cycles.
研究领域:
药物化学
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药剂学
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物理化学
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分离科学
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吸附科学
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天然产物提取
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药物代谢
✓ 已验证
DOI
高影响因子
POLYMER
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2021
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IF 4.43
Lu Shi,Wei Liu,Yanhu Xue,Mei Hong,Xiangling Ji
Temperature Rising Elution Fractionation (TREF) is effective for separating polyolefin resins according to crystallizability. A relatively low isothermal crystallization temperature is necessary to fractionate poly(1-butene) (PB-1) resin because of its slow crystallization kinetics . This study aims to investigate the influence of isothermal crystallization temperature of TREF on the fractionation and chain microstructure of eluted fractions for one poly(1-butene-co-ethylene) with 5.8 mol% ethylene. The resin is fractionated using P-TREF under four different isothermal crystallization temperatures, i.e. 0 °C, −5 °C, −10 °C, and −30 °C, and then the fractions are characterized by high-temperature gel permeation chromatography (HT-GPC), 13 C nuclear magnetic resonance spectroscopy ( 13 C NMR), and differential scanning calorimetry (DSC) to acquire their chain microstructure information. The isothermal crystallization temperature significantly affects the nucleation and growth of the crystals, which consequently results in differences in the relative content of eluted fractions. With the decrease of isothermal crystallization temperature from 0 °C to −30 °C, the copolymer is fractionated more effectively since fractions are more evenly distributed among elution temperatures rather than concentrated at lower elution temperatures. Furthermore, the isothermal crystallization temperature influences the chain microstructure of fractions obtained at the same elution temperature, which are different in ethylene content, isotacticity, and average sequence length. The distribution of ethylene content and isotacticity becomes broader with the decrease in isothermal crystallization temperature. Lower isothermal crystallization temperature is conducive to effective separation of the fractions with weak crystallizability. These results are of great significance for the selection of fractionation conditions and chain microstructure analysis of poly(1-butene-co-ethylene) resins.
研究领域:
高分子化学
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材料科学
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聚合物表征
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热分析
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核磁共振波谱学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2016
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IF 2.196
Peizhu Zheng,Dongxing Cai,Jihua Zhao,Weiguo Shen
The mixed surfactants of dodecyltrimethylammonium bromide (DTAB) and 1-dodecyl-3-methylimidazolium bromide (C 12 mimBr) in aqueous solutions were studied by measurement of electrical conductivity and isothermal titration microcalorimetry (ITC). The critical micelle concentrations (cmc) and the degree of dissociations of counter ions were determined for this system at various surfactant compositions, and the thermodynamic properties of micellization were evaluated. A one-parameter Margules equation was used to fit the cmc values to calculate the mole fraction, the activity coefficients of two surfactant components and the excess properties in mixed micelles.
研究领域:
胶体化学
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物理化学
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表面化学
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热力学
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溶液化学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2016
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IF 2.76
Shanshan Zhang,Xuerui Chen,Shiping Ding,Qunfang Lei,Wenjun Fang
The interactions of human serum albumin (HSA) with four cationic gemini surfactants and four single-chain surfactants have been investigated from the measurements of fluorescence spectroscopy, dynamic lights scattering (DLS), zeta potential, and circular dichroism (CD). The fluorescence results show the binding strength of surfactants to HSA, along with the blue shift under the maximum emission wavelength ( λ max ) which is sensitive to the protein conformations. It has been found that the hydrodynamic diameters of the protein aggregates are enlarged and the electrokinetic potentials of them get positive with increasing the concentration of the surfactants. The conformational transformation of the secondary structures of surfactant–HSA aggregates has been confirmed through the quantitative analysis of the CD spectra. The isothermal titration microcalorimetry (ITC) has been employed to further analyze the binding process of single-chain surfactants to HSA. The comprehensive results obtained from various approaches have shown that both hydrophobic and electrostatic interactions are present in the cationic surfactant–HSA systems. Compared with the corresponding single-chain surfactants, the gemini ones have much stronger binding ability to induce the unfolding of HSA. These investigations on the interactions between HSA and surfactants with the altered chain architecture in different concentration regimes can facilitate the application of surfactant-protein systems in pharmaceutical, biotechnology and related fields.
研究领域:
生物物理化学
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分子生物学
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药剂学
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蛋白质科学
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药物代谢
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胶体与界面科学
✓ 已验证
DOI
高影响因子
THERMOCHIMICA ACTA
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2016
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IF 1.938
Lipeng Wang,Fucheng Zhang,Yongping Bai,Liping Ding
The kinetic of non-isothermal crystallization of Poly (ethylene terephthalate-co-sodium-5-sulfo- iso -phthalate) (PETI) was investigated using differential scanning calorimetry (DSC). Various macrokinetic models namely the Avrami, Tobin, Ozawa, and Ziabicki were used to describe the non-isothermal crystallization process of PETI. Both of the Avrami crystallization rate constant and the Tobin crystallization rate constant were observed to increase with increasing cooling rate. The Avrami model is better than the Tobin model to describe the non-isothermal crystallization process of PETI. The Ozawa crystallization rate K O was found to decrease with increasing cooling rate, while Ziabicki’s kinetic crystallizability parameter G Z was found to increase with increasing cooling rate. The effective energy barrier △E for non-isothermal crystallization process of PETI, analyzed based on the differential iso-conversional method of Friedman, was found to be an increasing function of the relative crystallinity.
研究领域:
高分子化学
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材料科学
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物理化学
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热分析
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聚合物结晶
✓ 已验证
DOI
高影响因子
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