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Christoph Syldatk - One of the best experts on this subject based on the ideXlab platform.
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erratumerratum to Zeta Potential Measurement as a diagnostic tool in enzyme immobilisation colloids surf b biointerf 66 2008 39 44
Colloids and Surfaces B: Biointerfaces, 2008Co-Authors: Nadja Schultz, George Metreveli, Fritz H. Frimmel, Matthias Franzreb, Christoph SyldatkAbstract:a Biosystems Department, Riso National Laboratory for Sustainable Energy, Technical University of Denmark-DTU, Building 330, P.O. Box 49, DK-4000 Roskilde, Denmark b Engler-Bunte-Institute, Chair of Water Chemistry, University of Karlsruhe (TH), Engler-Bunte-Ring 1, D-76131 Karlsruhe, Germany c Research Center Karlsruhe, Institute of Technical Chemistry, Hermann-von-Helrnholz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany d Institute of Engineering in Life Science, Technical Biology Unit, University of Karlsruhe (TH), Engler-Bunte-Ring 1, D-76131 Karlsruhe, Germany
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Zeta Potential Measurement as a diagnostic tool in enzyme immobilisation
Colloids and Surfaces B: Biointerfaces, 2008Co-Authors: Nadja Schultz, George Metreveli, Fritz H. Frimmel, Matthias Franzreb, Christoph SyldatkAbstract:The efficiency of binding during enzyme immobilisation does not only depend on the chemical properties of the enzyme and the matrix particle, but also on their surface Potential. Zeta Potential quantifies the electrostatic interactions between enzyme and matrix particles, and can therefore, be used as an indicator of the binding efficiency in the enzyme immobilisation studies. In order to establish a correlation between the Zeta Potential and the binding efficiency, we used CALA (Candida antarctica A-type lipase) as a model protein for immobilisation on non-porous magnetic microparticles with epoxy (M-PVA E02), carboxy (M-PVA C12) and amine (M-PVA N12) terminations. We observed maximal binding of CALA onto the M-PVA N12 beads, due to the electrostatic attraction between negatively charged protein and carrier particles with slightly positive Zeta Potential. The binding of CALA was lower when M-PVA E02 beads were used, followed by M-PVA C12 beads. The decreasing binding efficiency was obviously the result of increasing electrostatic repulsion between the interaction partners. This could be correlated to the increasing negative Zeta Potential of the magnetic particles. Moreover, the medium of suspension of the particles also makes a significant difference. We found highest specific activity of the lipase immobilised on M-PVA E02 beads in a medium concentrated buffer (0.3 M). The results demonstrate a clear correlation between Zeta Potential and binding efficiency but no correlation between the bead related specific activity and the Zeta Potential. These findings are advocating the possibility of using the Zeta Potential as a diagnostic tool in enzyme immobilisation.
Zhongyi Jiang - One of the best experts on this subject based on the ideXlab platform.
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a novel positively charged composite nanofiltration membrane prepared by bio inspired adhesion of polydopamine and surface grafting of poly ethylene imine
Journal of Membrane Science, 2014Co-Authors: Runna Zhang, Xueting Zhao, Jiaojiao Zhao, Zhongyi JiangAbstract:Abstract Novel positively charged composite nanofiltration membranes were facilely prepared by polydopamine (PDA) deposition followed by poly(ethylene imine) (PEI) grafting on polyethersulfone (PES) substrates. Scanning election microscope (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), Zeta Potential Measurement and water contact angle Measurement were employed to characterize the surface chemical composition and morphology of the resultant membranes. The rejection of salts was increased but the pure water flux was decreased with the increase of PDA deposition time, PEI concentration, PEI reaction temperature and time. The salts rejection followed the sequence: MgCl 2 >CaCl 2 >MgSO 4 >Na 2 SO 4 , confirming that the membranes were positively charged. The rejection of MgCl 2 could reach 73.7%, whereas the rejection of CaCl 2 was 57.1%. Moreover, the membranes exhibited a superior rejection of up to 96.5% for cationic dyes.
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a novel positively charged composite nanofiltration membrane prepared by bio inspired adhesion of polydopamine and surface grafting of poly ethylene imine
Journal of Membrane Science, 2014Co-Authors: Runnan Zhang, Xueting Zhao, Jiaojiao Zhao, Yanlei Su, Yafei Li, Zhongyi JiangAbstract:Abstract Novel positively charged composite nanofiltration membranes were facilely prepared by polydopamine (PDA) deposition followed by poly(ethylene imine) (PEI) grafting on polyethersulfone (PES) substrates. Scanning election microscope (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), Zeta Potential Measurement and water contact angle Measurement were employed to characterize the surface chemical composition and morphology of the resultant membranes. The rejection of salts was increased but the pure water flux was decreased with the increase of PDA deposition time, PEI concentration, PEI reaction temperature and time. The salts rejection followed the sequence: MgCl 2 >CaCl 2 >MgSO 4 >Na 2 SO 4 , confirming that the membranes were positively charged. The rejection of MgCl 2 could reach 73.7%, whereas the rejection of CaCl 2 was 57.1%. Moreover, the membranes exhibited a superior rejection of up to 96.5% for cationic dyes.
Nadja Schultz - One of the best experts on this subject based on the ideXlab platform.
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erratumerratum to Zeta Potential Measurement as a diagnostic tool in enzyme immobilisation colloids surf b biointerf 66 2008 39 44
Colloids and Surfaces B: Biointerfaces, 2008Co-Authors: Nadja Schultz, George Metreveli, Fritz H. Frimmel, Matthias Franzreb, Christoph SyldatkAbstract:a Biosystems Department, Riso National Laboratory for Sustainable Energy, Technical University of Denmark-DTU, Building 330, P.O. Box 49, DK-4000 Roskilde, Denmark b Engler-Bunte-Institute, Chair of Water Chemistry, University of Karlsruhe (TH), Engler-Bunte-Ring 1, D-76131 Karlsruhe, Germany c Research Center Karlsruhe, Institute of Technical Chemistry, Hermann-von-Helrnholz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany d Institute of Engineering in Life Science, Technical Biology Unit, University of Karlsruhe (TH), Engler-Bunte-Ring 1, D-76131 Karlsruhe, Germany
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Zeta Potential Measurement as a diagnostic tool in enzyme immobilisation
Colloids and Surfaces B: Biointerfaces, 2008Co-Authors: Nadja Schultz, George Metreveli, Fritz H. Frimmel, Matthias Franzreb, Christoph SyldatkAbstract:The efficiency of binding during enzyme immobilisation does not only depend on the chemical properties of the enzyme and the matrix particle, but also on their surface Potential. Zeta Potential quantifies the electrostatic interactions between enzyme and matrix particles, and can therefore, be used as an indicator of the binding efficiency in the enzyme immobilisation studies. In order to establish a correlation between the Zeta Potential and the binding efficiency, we used CALA (Candida antarctica A-type lipase) as a model protein for immobilisation on non-porous magnetic microparticles with epoxy (M-PVA E02), carboxy (M-PVA C12) and amine (M-PVA N12) terminations. We observed maximal binding of CALA onto the M-PVA N12 beads, due to the electrostatic attraction between negatively charged protein and carrier particles with slightly positive Zeta Potential. The binding of CALA was lower when M-PVA E02 beads were used, followed by M-PVA C12 beads. The decreasing binding efficiency was obviously the result of increasing electrostatic repulsion between the interaction partners. This could be correlated to the increasing negative Zeta Potential of the magnetic particles. Moreover, the medium of suspension of the particles also makes a significant difference. We found highest specific activity of the lipase immobilised on M-PVA E02 beads in a medium concentrated buffer (0.3 M). The results demonstrate a clear correlation between Zeta Potential and binding efficiency but no correlation between the bead related specific activity and the Zeta Potential. These findings are advocating the possibility of using the Zeta Potential as a diagnostic tool in enzyme immobilisation.
Wenqing Qin - One of the best experts on this subject based on the ideXlab platform.
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innovative application of sodium tripolyphosphate for the flotation separation of scheelite from calcite
Minerals Engineering, 2021Co-Authors: Xu Wang, Wenqing Qin, Wenhao Jia, Congren Yang, Fen Jiao, Yanfang Cui, Zhengquan Zhang, Hao SongAbstract:Abstract The Potential of sodium tripolyphosphate as a depressant for selective flotation separation of scheelite from calcite is investigated by the micro-flotation tests and industrial scale tests in this study. The depression mechanism of sodium tripolyphosphate is also studied by adsorption Measurement, Zeta Potential Measurement and FTIR spectra. As suggested from the flotation test results, sodium tripolyphosphate have a good selective depression effect on calcite. The results of adsorption test, Zeta Potential Measurement, and FTIR spectra indicate that the selective adsorption of sodium tripolyphosphate on calcite surface hindered the further adsorption of FX-6 type sodium oleate (FX-6) on calcite surface, which prevented the flotation of calcite. However, the pretreatment of sodium tripolyphosphate have little effect on the subsequent adsorption of FX-6 on the scheelite surface, and scheelite still maintain good floatability. The selective adsorption of sodium tripolyphosphate occur between phosphate and Ca2+ exposed on the calcite surface. Sodium tripolyphosphate have the Potential to be used as an alternative calcite depressant to the flotation separation of scheelite and calcite.
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hydrophobic agglomeration of rhodochrosite fines in aqueous suspensions with sodium oleate
Powder Technology, 2021Co-Authors: Song Zou, Shuai Wang, Hong Zhong, Wenqing QinAbstract:Abstract Hydrophobic agglomeration of rhodochrosite fines in aqueous suspensions with sodium oleate has been investigated through wettability Measurement, optical microscopy observation, laser-based particle size detection, micro-flotation test, Zeta Potential Measurement in this work. The experimental results indicated that the hydrophobicity of rhodochrosite was a dominant factor for the hydrophobic agglomeration. And a higher sodium oleate concentration could contribute to bigger agglomeration particle size and more regular agglomerates. The increased apparent particle size of minerals through hydrophobic agglomeration interaction was conducive to the micro-flotation recovery improvement of rhodochrosite fines in spite of a simultaneous increase in the negative Zeta Potential of rhodochrosite, meaning that the chemical adsorption was the primary reason between sodium oleate and rhodochrosite. Furtherly, the data calculated from extended DLVO theory was also convinced that hydrophobic interaction between the particles increased much more strongly than electrostatic repulsion from the adsorption of sodium oleate.
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flotation separation of fluorite from calcite using polyaspartate as depressant
Minerals Engineering, 2018Co-Authors: Hailing Zhu, Chen Zi-chen, Wenqing Qin, Fen Jiao, Liyuan Chai, Wenhao JiaAbstract:Abstract Flotation separation of carbonate fluorite ore is a puzzle in mineral processing. In this study, the flotation separation of fluorite from calcite using polyaspartate (PASP) as depressant and sodium oleate (NaOL) as collector was investigated, and the adsorption mechanism was analyzed by Zeta Potential Measurement and infrared spectrum (IR) analysis. Flotation results show that NaOL exhibits excellent collecting performance to fluorite and calcite. Moreover, PASP addition can selectively inhibit calcite. A concentrate containing 93.56% CaF2 with a recovery of 57.82% is obtained in the closed-circuit flotation experiment on the real ore. Zeta Potential Measurement and IR analysis results indicate that both PASP and NaOL can adsorb on fluorite and calcite surface individually. Additionally, the adsorption of PASP can hinder the adsorption of NaOL on calcite surface but exert little influence on the adsorption of NaOL on fluorite surface. Therefore, PASP is an effective depressant for flotation separation of fluorite from calcite.
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depression mechanism of the zinc sulfate and sodium carbonate combined inhibitor on talc
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2016Co-Authors: Xingjie Wang, Wenqing Qin, Ruizeng Liu, Fen JiaoAbstract:Abstract Solution chemical calculation, Zeta Potential Measurement and flotation test were introduced to verify the effective inhibiting component and illustrate the inhibition mechanism of ZnSO 4 and Na 2 CO 3 as a combined inhibitor for talc. Solution chemical speciation calculations indicated that the formation of solid state Zn(OH) 2 occurred in all initial concentration ranges of ZnSO 4 . The higher the initial concentration was, the lower the pH values were when solid state Zn(OH) 2 appeared. The solid state ZnCO 3 formed when the initial concentrations of ZnSO 4 were higher than 1 × 10 −4 mol/L, and the formation was qualified in certain concentration ranges of Na 2 CO 3 . Additionally, the ranges extended with the increasing initial concentration of ZnSO 4. Along with the results of the Zeta Potential Measurement and flotation test, it demonstrated that the effective inhibiting components of the combined inhibitor were solid state ZnCO 3 and Zn(OH) 2 , while ZnCO 3 played a major role. When the combined inhibitor is used for the depression of talc, the addition of Na 2 CO 3 and initial concentration of ZnSO 4 should be strictly controlled at a restricted level that is suitable for the formation of solid state ZnCO 3 . ZnSO 4 and Na 2 CO 3 is an effective combined inhibitor for talc in flotation separation of talc and molybdenite.
Fritz H. Frimmel - One of the best experts on this subject based on the ideXlab platform.
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erratumerratum to Zeta Potential Measurement as a diagnostic tool in enzyme immobilisation colloids surf b biointerf 66 2008 39 44
Colloids and Surfaces B: Biointerfaces, 2008Co-Authors: Nadja Schultz, George Metreveli, Fritz H. Frimmel, Matthias Franzreb, Christoph SyldatkAbstract:a Biosystems Department, Riso National Laboratory for Sustainable Energy, Technical University of Denmark-DTU, Building 330, P.O. Box 49, DK-4000 Roskilde, Denmark b Engler-Bunte-Institute, Chair of Water Chemistry, University of Karlsruhe (TH), Engler-Bunte-Ring 1, D-76131 Karlsruhe, Germany c Research Center Karlsruhe, Institute of Technical Chemistry, Hermann-von-Helrnholz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany d Institute of Engineering in Life Science, Technical Biology Unit, University of Karlsruhe (TH), Engler-Bunte-Ring 1, D-76131 Karlsruhe, Germany
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Zeta Potential Measurement as a diagnostic tool in enzyme immobilisation
Colloids and Surfaces B: Biointerfaces, 2008Co-Authors: Nadja Schultz, George Metreveli, Fritz H. Frimmel, Matthias Franzreb, Christoph SyldatkAbstract:The efficiency of binding during enzyme immobilisation does not only depend on the chemical properties of the enzyme and the matrix particle, but also on their surface Potential. Zeta Potential quantifies the electrostatic interactions between enzyme and matrix particles, and can therefore, be used as an indicator of the binding efficiency in the enzyme immobilisation studies. In order to establish a correlation between the Zeta Potential and the binding efficiency, we used CALA (Candida antarctica A-type lipase) as a model protein for immobilisation on non-porous magnetic microparticles with epoxy (M-PVA E02), carboxy (M-PVA C12) and amine (M-PVA N12) terminations. We observed maximal binding of CALA onto the M-PVA N12 beads, due to the electrostatic attraction between negatively charged protein and carrier particles with slightly positive Zeta Potential. The binding of CALA was lower when M-PVA E02 beads were used, followed by M-PVA C12 beads. The decreasing binding efficiency was obviously the result of increasing electrostatic repulsion between the interaction partners. This could be correlated to the increasing negative Zeta Potential of the magnetic particles. Moreover, the medium of suspension of the particles also makes a significant difference. We found highest specific activity of the lipase immobilised on M-PVA E02 beads in a medium concentrated buffer (0.3 M). The results demonstrate a clear correlation between Zeta Potential and binding efficiency but no correlation between the bead related specific activity and the Zeta Potential. These findings are advocating the possibility of using the Zeta Potential as a diagnostic tool in enzyme immobilisation.
