The Nd(III)extraction in flat renewal supported liquid membrane(FRSLM),with polyvinylidene fluoride membrane and renewal solution including HNO3 solution as the stripping solution and di(2-ethylhexyl)phosphoric acid(D...The Nd(III)extraction in flat renewal supported liquid membrane(FRSLM),with polyvinylidene fluoride membrane and renewal solution including HNO3 solution as the stripping solution and di(2-ethylhexyl)phosphoric acid(D2EHPA)dissolved in kerosene as the membrane solution,was investigated.The effects of pH in the feed phase,volume ratio of membrane solution to stripping solution,concentra-tion of HNO3 solution and concentration of carrier in the renewal phase on extraction of Nd(III)were also studied,respectively.As a result,the optimum extraction conditions of Nd(III)were obtained when concentration of HNO3 solution was 4.00 mol/L,concentration of D2EHPA was 0.100 mol/L,and volume ratio of membrane solution to stripping solution was 1.00 in the renewal phase,and pH was 4.60 in the feed phase.When initial concentration of Nd(III)was 2.00×10-4 mol/L,the extraction percentage of Nd(III)was up to 92.9%in 75 min.展开更多
In this study, poly(vinilydene fluoride-co-hexafluoropropylene)(PVDF-HFP) was used for preparation of hydrophobic membranes using non-solvent induced phase inversion(NIPS) technique. PVDF-HFP copolymer with concentrat...In this study, poly(vinilydene fluoride-co-hexafluoropropylene)(PVDF-HFP) was used for preparation of hydrophobic membranes using non-solvent induced phase inversion(NIPS) technique. PVDF-HFP copolymer with concentrations of 10 wt% and 12 wt% was prepared to investigate the effect of polymer concentration on pore structure,morphology, hydrophobicity and performance of prepared membranes. Besides, the use of two coagulation baths with the effects of parameters such as coagulant time, polymer type and concentration, and the amount of nonsolvent were studied. The performance of prepared membranes was evaluated based on the permeability and selectivity of oxygen and nitrogen from a gas mixture of nitrogen/oxygen under operating conditions of feed flow rate(1–5 L·min-1), inlet pressure to membrane module(0.1–0.5 MPa) and temperatures between 25 and 45 °C. The results showed that the use of two coagulation baths with different compositions of distillated water and isopropanol,coagulant time, polymer type and concentration, and the amount of non-solvent additive have the most effect on pore structure, morphology, thickness, roughness and crystallinity of fabricated membranes. Porosity ranges for the three fabricated membranes were determined, where the maximum porosity was 73.889% and the minimum value was 56.837%. Also, the maximum and minimum average thicknesses of membrane were 320.85 μm and115 μm. Besides, the values of 4.7504 × 10-7 mol· m-2· s-1· Pa-1, 0.525 and 902.126 nm were achieved for maximum oxygen permeance, O2/N2 selectivity and roughness, respectively.展开更多
Over the past decades,membrane-based separation processes have found numerous applications in various industries.Membrane contactor is an important part of the separation of dissolved gas in the early stage of gas det...Over the past decades,membrane-based separation processes have found numerous applications in various industries.Membrane contactor is an important part of the separation of dissolved gas in the early stage of gas detection.In this paper,to improve efficiency in the detection of the dissolved gas phase in seawater,a better flat membrane contactor is proposed to achieve efficient degassing,inspired by the way fish breathe underwater and the special structure of fish gills.The bioinspired flow channel structures in the flat membrane contactor are suggested along with the distribution of internal blood vessels in the gill platelet and the feature of the gill platelet surface.Using 3D printing,the special degassing devices are manufactured,and comparative analysis of relevant flow parameters is made using different flow channels,combined with the CFD simulation.The final result showed that the proposed flow channel in the degasser achieves a better degassing effect compared with conventional flow channel when the membrane contact area is limited,which can provide good conditions for subsequent gas detection.展开更多
High performance polyvinylidene fluoride （PVDF） flat sheet ultrafiltration （UF） membranes have been prepared by an immersion precipitation phase inversion method using perfluorosulfonic acid （PFSA） as a pore for...High performance polyvinylidene fluoride （PVDF） flat sheet ultrafiltration （UF） membranes have been prepared by an immersion precipitation phase inversion method using perfluorosulfonic acid （PFSA） as a pore former and as a hydrophilic component of the membranes and polyethylene glycol （Mw = 400） （PEG400） as a pore forming agent. The effects of the presence of PEG and the concentration of the PFSA on the phase separation of the casting solutions and on the morphologies and performance of UF membranes including their porosity, water flux, rejection of bovine serum albumin （BSA） protein, and anti-fouling property were investigated. Phase diagrams, viscosities and the phase separations upon exposure to water vapor showed that both PEG400 and PFSA promoted demixing of the casting solution. Scanning electron microscopy measurements showed that the PVDF-PFSA blend membranes had more macropores and finger-like structures than the native PVDF membranes. The PVDF-PFSA membrane （5 wt-% PEG400 ＋ 5 wt-% PFSA） had a pure water flux of 141.7L/m2.h, a BSA rejection of 90.1% and a relative pure water flux reduction （RFR） of 15.28%. These properties were greatly superior to those of the native PVDF membrane （pure water flux of 5.6 L/m2. h, BSA rejection of 96.3% and RFR of 42.86%）.展开更多
基金Project supported by the National Natural Science Foundation of China for Young Scientists(51109197)Foundation for Planning Project of West Action of Chinese Academy of Sciences(KZCX2-XB2-13)Research Fund for Excellent Doctoral Thesis of Xi'an University of Technology(602-210805)
文摘The Nd(III)extraction in flat renewal supported liquid membrane(FRSLM),with polyvinylidene fluoride membrane and renewal solution including HNO3 solution as the stripping solution and di(2-ethylhexyl)phosphoric acid(D2EHPA)dissolved in kerosene as the membrane solution,was investigated.The effects of pH in the feed phase,volume ratio of membrane solution to stripping solution,concentra-tion of HNO3 solution and concentration of carrier in the renewal phase on extraction of Nd(III)were also studied,respectively.As a result,the optimum extraction conditions of Nd(III)were obtained when concentration of HNO3 solution was 4.00 mol/L,concentration of D2EHPA was 0.100 mol/L,and volume ratio of membrane solution to stripping solution was 1.00 in the renewal phase,and pH was 4.60 in the feed phase.When initial concentration of Nd(III)was 2.00×10-4 mol/L,the extraction percentage of Nd(III)was up to 92.9%in 75 min.
文摘In this study, poly(vinilydene fluoride-co-hexafluoropropylene)(PVDF-HFP) was used for preparation of hydrophobic membranes using non-solvent induced phase inversion(NIPS) technique. PVDF-HFP copolymer with concentrations of 10 wt% and 12 wt% was prepared to investigate the effect of polymer concentration on pore structure,morphology, hydrophobicity and performance of prepared membranes. Besides, the use of two coagulation baths with the effects of parameters such as coagulant time, polymer type and concentration, and the amount of nonsolvent were studied. The performance of prepared membranes was evaluated based on the permeability and selectivity of oxygen and nitrogen from a gas mixture of nitrogen/oxygen under operating conditions of feed flow rate(1–5 L·min-1), inlet pressure to membrane module(0.1–0.5 MPa) and temperatures between 25 and 45 °C. The results showed that the use of two coagulation baths with different compositions of distillated water and isopropanol,coagulant time, polymer type and concentration, and the amount of non-solvent additive have the most effect on pore structure, morphology, thickness, roughness and crystallinity of fabricated membranes. Porosity ranges for the three fabricated membranes were determined, where the maximum porosity was 73.889% and the minimum value was 56.837%. Also, the maximum and minimum average thicknesses of membrane were 320.85 μm and115 μm. Besides, the values of 4.7504 × 10-7 mol· m-2· s-1· Pa-1, 0.525 and 902.126 nm were achieved for maximum oxygen permeance, O2/N2 selectivity and roughness, respectively.
基金funded by Science-Technology Development Plan Project of Jilin Province,20210203099SF,Zhiyong ChangScience and Technology Development Project of Jilin Province,20190303061SF,Yongming Yao13th Five-Year Plan Scientific Research Foundation of the Education Department of Jilin Province,JJKH20190190KJ,Zhiyong Chang.
文摘Over the past decades,membrane-based separation processes have found numerous applications in various industries.Membrane contactor is an important part of the separation of dissolved gas in the early stage of gas detection.In this paper,to improve efficiency in the detection of the dissolved gas phase in seawater,a better flat membrane contactor is proposed to achieve efficient degassing,inspired by the way fish breathe underwater and the special structure of fish gills.The bioinspired flow channel structures in the flat membrane contactor are suggested along with the distribution of internal blood vessels in the gill platelet and the feature of the gill platelet surface.Using 3D printing,the special degassing devices are manufactured,and comparative analysis of relevant flow parameters is made using different flow channels,combined with the CFD simulation.The final result showed that the proposed flow channel in the degasser achieves a better degassing effect compared with conventional flow channel when the membrane contact area is limited,which can provide good conditions for subsequent gas detection.
基金Acknowledgements The work was supported by the National Natural Science Foundation of China （Grant No. 20904031） and the Shanghai Leading Academic Discipline Project （No, B202）. Thanks for Instrumental Analysis Center of Shanghai Jiao Tong University.
文摘High performance polyvinylidene fluoride （PVDF） flat sheet ultrafiltration （UF） membranes have been prepared by an immersion precipitation phase inversion method using perfluorosulfonic acid （PFSA） as a pore former and as a hydrophilic component of the membranes and polyethylene glycol （Mw = 400） （PEG400） as a pore forming agent. The effects of the presence of PEG and the concentration of the PFSA on the phase separation of the casting solutions and on the morphologies and performance of UF membranes including their porosity, water flux, rejection of bovine serum albumin （BSA） protein, and anti-fouling property were investigated. Phase diagrams, viscosities and the phase separations upon exposure to water vapor showed that both PEG400 and PFSA promoted demixing of the casting solution. Scanning electron microscopy measurements showed that the PVDF-PFSA blend membranes had more macropores and finger-like structures than the native PVDF membranes. The PVDF-PFSA membrane （5 wt-% PEG400 ＋ 5 wt-% PFSA） had a pure water flux of 141.7L/m2.h, a BSA rejection of 90.1% and a relative pure water flux reduction （RFR） of 15.28%. These properties were greatly superior to those of the native PVDF membrane （pure water flux of 5.6 L/m2. h, BSA rejection of 96.3% and RFR of 42.86%）.
