Worldwide environment has resulted in a limit on the sulfur content of gasoline.It is urgent to investigate the desulfurization of gasoline.The polydimethylsiloxane(PDMS)/polyetherimide(PEI)composite membranes were pr...Worldwide environment has resulted in a limit on the sulfur content of gasoline.It is urgent to investigate the desulfurization of gasoline.The polydimethylsiloxane(PDMS)/polyetherimide(PEI)composite membranes were prepared by casting a PDMS solution onto porous PEI substrates and characterized by scanning electron microscope(SEM).The membranes were used for sulfur removal from gasoline by pervaporation.The effects of feed temperature,sulfur content in the feed and PDMS layer thickness on membrane performance were investigated,and an activation energy of permeation was obtained.Experimental results indicated that higher feed temperature yielded higher total flux and lower sulfur enrichment factor.The total flux varied little with the increase of sulfur content in the feed,but the sulfur enrichment factor first increased with the amount of thiophene added into the gasoline,and then the variation was little.The increase of PDMS layer thickness resulted in a smaller flux but a larger sulfur enrichment factor.The result indicates that the PDMS/PEI composite membranes are promising for desulfurization by pervaporation.展开更多
The recovery or capture of one or more components from gas mixture by membrane separation has become a research focus in recent years.This study investigates the gas-membrane solution equilibrium,for which Henry's...The recovery or capture of one or more components from gas mixture by membrane separation has become a research focus in recent years.This study investigates the gas-membrane solution equilibrium,for which Henry's law is not applicable if the gas phase is a mixture.This problem can be solved by using UNIQUAC model to calculate the activity coefficient of gas dissolved in the membrane.A method was proposed in this study to obtain the gas-membrane interaction parameter for UNIQUAC model.By the experiments of gas permeation through polydimethylsiloxane PDMS membrane,the solubility coefficients of some gases(N2,CO2,CH4) were measured.Through non-linear fitting UNIQUAC model to the experimental results from this study and in literature(H2,O2,C3H8),the gas-membrane interaction parameters for these gases were obtained.Based on these parameters,the activity coefficients of the dissolved gas were calculated by UNIQUAC model,and their values agree well with the experimental data.These results confirm the feasibility and effectiveness of the proposed method,which makes it possible to better predict gas-membrane solution equilibrium.展开更多
Gold nanoparticles-dimethylsiloxane(AuNPs-PDMS) membrane is a novel composite material in biochemical technology an d micro-electro-mechanical system(MEMS) research.It is widely used in biomed ici ne,biochemical detec...Gold nanoparticles-dimethylsiloxane(AuNPs-PDMS) membrane is a novel composite material in biochemical technology an d micro-electro-mechanical system(MEMS) research.It is widely used in biomed ici ne,biochemical detection and en vironmental protection due to its biocompatibility,elasticity and electric char acteristics.In this paper,the characteristics of the composite membrane were d escribed,and four methods for fabricating AuNPs-PDMS composite membranes were reviewed in detail.Besides,the advantages and disadvantages of the four method s were summarized,and the present problems and future researches were proposed.展开更多
Water striders have remarkable water-repellent legs that enable them to stand effortlessly and move quickly on water.Fluid physics indicates this feature is due to a surface-tension effect caused by the special hierar...Water striders have remarkable water-repellent legs that enable them to stand effortlessly and move quickly on water.Fluid physics indicates this feature is due to a surface-tension effect caused by the special hierarchical structure of the legs,which are covered with a large number of inclined setae with fine nanogrooves inducing water resistance.This inspires us to fabricate special water-repellent structure on functional surfaces through the cooperation between the surface treatment and the surface micro-and nanostructures,which may bring great advantages in a wide variety of applications.In this paper we present a procedure for fabricating biomimetic water strider legs covered with setae using Polycarbonate Track-Etched(PCTE)membranes as templates.By choosing appropriate membrane lengths,diameters,pitches and densities of the setae,the biomimetic legs can be fabricated conveniently and at a low cost.Furthermore we investigated the relationship between stiffness of the molding materials,high aspect ratio and density,which affect the fidelity of fabrication and self adhesion,to optimize the stability of setae.The knowledge we gained from this study will offer important insights into the biomimetic design and fabrication of water strider setae.展开更多
基金Supported by the National Basic Research Program of China(2009CB623404)the National Natural Science Foundation of China(50708109,20736003)the National High Technology Research and Development Program of China(2007AA06Z317)
文摘Worldwide environment has resulted in a limit on the sulfur content of gasoline.It is urgent to investigate the desulfurization of gasoline.The polydimethylsiloxane(PDMS)/polyetherimide(PEI)composite membranes were prepared by casting a PDMS solution onto porous PEI substrates and characterized by scanning electron microscope(SEM).The membranes were used for sulfur removal from gasoline by pervaporation.The effects of feed temperature,sulfur content in the feed and PDMS layer thickness on membrane performance were investigated,and an activation energy of permeation was obtained.Experimental results indicated that higher feed temperature yielded higher total flux and lower sulfur enrichment factor.The total flux varied little with the increase of sulfur content in the feed,but the sulfur enrichment factor first increased with the amount of thiophene added into the gasoline,and then the variation was little.The increase of PDMS layer thickness resulted in a smaller flux but a larger sulfur enrichment factor.The result indicates that the PDMS/PEI composite membranes are promising for desulfurization by pervaporation.
文摘The recovery or capture of one or more components from gas mixture by membrane separation has become a research focus in recent years.This study investigates the gas-membrane solution equilibrium,for which Henry's law is not applicable if the gas phase is a mixture.This problem can be solved by using UNIQUAC model to calculate the activity coefficient of gas dissolved in the membrane.A method was proposed in this study to obtain the gas-membrane interaction parameter for UNIQUAC model.By the experiments of gas permeation through polydimethylsiloxane PDMS membrane,the solubility coefficients of some gases(N2,CO2,CH4) were measured.Through non-linear fitting UNIQUAC model to the experimental results from this study and in literature(H2,O2,C3H8),the gas-membrane interaction parameters for these gases were obtained.Based on these parameters,the activity coefficients of the dissolved gas were calculated by UNIQUAC model,and their values agree well with the experimental data.These results confirm the feasibility and effectiveness of the proposed method,which makes it possible to better predict gas-membrane solution equilibrium.
基金National Natural Science Foundation of China (No.51105267, No.91123036)China Postdoctoral Science Foundation(No.2011M500542, No.2012T50248)+1 种基金National Research Foundation for the Doctoral Program of Higher Education of China (No.20111402120007)Shanxi Provincial Foundation for Returned Scholars (No.2011x10)
文摘Gold nanoparticles-dimethylsiloxane(AuNPs-PDMS) membrane is a novel composite material in biochemical technology an d micro-electro-mechanical system(MEMS) research.It is widely used in biomed ici ne,biochemical detection and en vironmental protection due to its biocompatibility,elasticity and electric char acteristics.In this paper,the characteristics of the composite membrane were d escribed,and four methods for fabricating AuNPs-PDMS composite membranes were reviewed in detail.Besides,the advantages and disadvantages of the four method s were summarized,and the present problems and future researches were proposed.
文摘Water striders have remarkable water-repellent legs that enable them to stand effortlessly and move quickly on water.Fluid physics indicates this feature is due to a surface-tension effect caused by the special hierarchical structure of the legs,which are covered with a large number of inclined setae with fine nanogrooves inducing water resistance.This inspires us to fabricate special water-repellent structure on functional surfaces through the cooperation between the surface treatment and the surface micro-and nanostructures,which may bring great advantages in a wide variety of applications.In this paper we present a procedure for fabricating biomimetic water strider legs covered with setae using Polycarbonate Track-Etched(PCTE)membranes as templates.By choosing appropriate membrane lengths,diameters,pitches and densities of the setae,the biomimetic legs can be fabricated conveniently and at a low cost.Furthermore we investigated the relationship between stiffness of the molding materials,high aspect ratio and density,which affect the fidelity of fabrication and self adhesion,to optimize the stability of setae.The knowledge we gained from this study will offer important insights into the biomimetic design and fabrication of water strider setae.
