Superhydrophobic poly(vinylidene fluoride) PVDF-SiO2 composite membranes with different % of SiO2 contents were prepared by electrospinning. The surface morphologies of the membranes are characterized by using scannin...Superhydrophobic poly(vinylidene fluoride) PVDF-SiO2 composite membranes with different % of SiO2 contents were prepared by electrospinning. The surface morphologies of the membranes are characterized by using scanning electron microscopy. The nanofibers in the membranes were stacked in layers to produce fully interconnected pores that resulted in high porosity. The incorporation of SiO2 into the nanofiber membrane improved the ionic conductivity from 0.2428 × 10-4Scm-1 to 7.731 × 10-4Scm-1 at room temperature. The surface roughness of the membranes increased with increasing the SiO2 content, while the average diameter of nanofibers was rarely affected. Superhydrophobic PVDF membrane with a contact angle larger than 136° was prepared by the electrospinning of the SiO2 functionalized PVDF. The surface composition of the membranes is analyzed by using FTIR and the contact angles and water drops on the surface of the membrane are measured. The contact angle experimental results of PVDF-SiO2 composite membranes showed an improvement of hydrophobicity with % of nano SiO2.展开更多
Novel amino （-NH2） functionalized mesoporous polyvinyl pyrrolidone （PVP）/SiO2 composite nanofiber membranes were fabricated by a one-step electrospinning method using poly （vinyl alcohol） and tetraethyl orthosil...Novel amino （-NH2） functionalized mesoporous polyvinyl pyrrolidone （PVP）/SiO2 composite nanofiber membranes were fabricated by a one-step electrospinning method using poly （vinyl alcohol） and tetraethyl orthosilicate （TEOS） mixed with cationic surfactant, cety｜trimethyl ammonium bromide （CTAB） as the structure directing agent. Ureidopropyltriethoxysilane was used for functionalization of the internal pore surfaces. The membranes were characterized by scanning electron microscopy （SEM）, high-resolution transmission electron microscopy （HRTEM） images, X-ray diffraction （XRD）, Fourier-transform infrared spectroscopy （FT-IR）, element analyzer and Nz adsorption-desorption isotherms, The nanofiber diameters, average pore diameters and surface areas were 100-700 nm, 2.86 nm and 873,62 m2/g, respectively. These mesoporous membranes functionalized with -NH2 groups exhibited very high adsorptions properties based on the adsorption of Cr3＋ from an aqueous solution. Equilibrium adsorption was achieved after approximately 20 rain and more than 97% of chronium ions in the solution were removed. The membrane could be regenerated through acidification.展开更多
Nanometer materials include roughly nanoparticle,nanotube, nanowire, nanofiber, nanofilm and nanoblock, among which nanofiber is defined as material with nanometer-sized diameter and longer than 1 micron in length. Th...Nanometer materials include roughly nanoparticle,nanotube, nanowire, nanofiber, nanofilm and nanoblock, among which nanofiber is defined as material with nanometer-sized diameter and longer than 1 micron in length. The research development of polymer nanofibers, including manufacture methods and properties of some polymer nanofibers as well as their potential applications is reviewed.展开更多
Niobium pentoxide(Nb2O5) has been extensively studied as anode materials for lithium ion batteries(LIBs) due to its good rate performance and safety advantages.However, the intrinsic low electronic conductivity has la...Niobium pentoxide(Nb2O5) has been extensively studied as anode materials for lithium ion batteries(LIBs) due to its good rate performance and safety advantages.However, the intrinsic low electronic conductivity has largely restricted its practical application. In this work, we report the construction of mesoporous T-Nb2O5 nanofibers by electrospinning followed by heat treatment in air. The interconnected mesoporous structure ensures a high surface area with easy electrolyte penetration. When used as anodes for LIBs, the mesoporous Nb2O5 electrode delivers a high reversible specific capacity of 238 mA h g-1 after 1,000 cycles at a current density of 1 A g-1 within a voltage range of 0.01–3.0 V.Even at a higher discharge cut-off voltage window of 1.0–3.0 V, it still possesses a high reversible capacity of166 mA h g-1 after 200 cycles. Moreover, the porous Nb2O5 electrode also exhibits excellent rate capability. The enhanced electrochemical performances are attributed to the synergistic effects of porous nanofiber structure and unique crystal structure of T-Nb2O5, which has endowed this material a large electrode-electrolyte contact area with improved electronic conductivity.展开更多
The use of linear amphiphilic block copolymers as templates is an important method for the preparation of mesoporous materials.However,the obtained assemblies are usually sensitive to synthetic conditions,which impede...The use of linear amphiphilic block copolymers as templates is an important method for the preparation of mesoporous materials.However,the obtained assemblies are usually sensitive to synthetic conditions,which impedes the preparation of such mesoporous materials in certain environments.Herein,we report a universal strategy applying an amphiphilic multiarm triblock copolymer in the preparation of mesoporous metal oxide nanofibers(NFs)using one metal oxide(TiO_(2),ZrO_(2),WO_(3),CeO_(2)),or two(TiO_(2)/WO 3,TiO_(2)/ZrO_(2),TiO_(2)/CeO_(2))and three(TiO_(2)/WO_(3)/CuO)metal oxides as composites.The template consists of modified β-cyclodextrin as the center of the macromolecule which is attached sequentially to a block of polystyrene,poly(acrylic acid),and poly(ethylene oxide).Under electrospinning conditions,stable unimolecular micelles are formed and effectively co-assemble with metal ions to form fibrous nanostructures.As indicated by various characterization methods,the synthesized TiO_(2) and its derived composite NFs maintain a straight and continuous fibrous structure after calcination,and TiO_(2) NFs exhibit uniform mesopores of 10.8 nm in diameter and a large Brunauer-Emmett-Teller surface area of 143.3 m^(2)g^(−1).Benefiting from the characteristic structure,still present after modification,Pt-decorated mesoporous TiO_(2) NFs display excellent ability in the visible-light photocatalytic degradation of tetracycline,which is superior to the commercial P25 catalyst.This study reveals a promising strategy for the preparation of fibrous mesoporous metal oxides.展开更多
To promote the energy density of symmetric all-solid-state supercapacitors(SCs),efforts have been dedicated to searching for high-performance electrode materials recently. In this paper,vanadium nitride(VN) nanofibers...To promote the energy density of symmetric all-solid-state supercapacitors(SCs),efforts have been dedicated to searching for high-performance electrode materials recently. In this paper,vanadium nitride(VN) nanofibers with mesoporous structure have been fabricated by a facile electrospinning method. Their crystal structures and morphology features were characterized by X-ray diffraction,scanning electron microscopy,and transmission electron microscopy. The mesoporous structure of VN nanofibers,which can provide short electrolyte diffusion routes and conducting electron transport pathways,is beneficial to their performance as a supercapacitor electrode. Under a stable electrochemical window of 1.0 V,VN nanofibers possess an excellent mass specific capacitance of 110.8 F/g at a scan rate of 5 mV/s. Moreover,the VN nanofibers were further assembled into symmetric all-solid-state SCs,achieving a high energy density of 0.89 mW·h/cm^3 and a high power density of 0.016 W/cm^3 over an operating potential range from 0 to 1.0 V. These results demonstrate that VN nanofibers could be potentially used for energy storage devices.展开更多
Sulfated zirconia/silica(SZ/SiO2) complex nanofibers were prepared by combining electronspinning technique and sol-gel method.First,a silica sol was electrospun at a voltage of 12 kV,then the as-electrospun silica nan...Sulfated zirconia/silica(SZ/SiO2) complex nanofibers were prepared by combining electronspinning technique and sol-gel method.First,a silica sol was electrospun at a voltage of 12 kV,then the as-electrospun silica nanofibers were immersed into a sulfated zirconia sol afterwards with a thermal treatment to obtain the SZ/SiO2 complex nanofibers.These fibers were examined by SEM,TEM,FTIR, XRD and SPS.The results indicate that the SZ nanopaticles with the average diameter of about 8 nm were disspered on the surface of silica fibers which had an average diameter of about 170 nm.The complex nanofibers had an amorphous structure.The observation of the surface-related transitions at the SPS spectrum indicates the presence of positive charges on the surface of the complex fibers.展开更多
The aim of this study was to achieve on-demand controlled drug release from the dual-drug-loadedpoly(lactic-co-glycolic acid)/mesoporous silica nanoparticles electrospun composite fibers by theapplication of ultrasoun...The aim of this study was to achieve on-demand controlled drug release from the dual-drug-loadedpoly(lactic-co-glycolic acid)/mesoporous silica nanoparticles electrospun composite fibers by theapplication of ultrasound irradiation.Two drugs were loaded in different part of the composite fibrousmaterials,and it was found that ultrasound as an external stimulus was able to control releaseof drugs due to both its thermal effect and non-thermal effect.With the selective irradiation ofultrasound,the drug carrier enabled to realize controlled release,and because of different locationin fibers and sensitivity of two different kinds of drugs to ultrasound irradiation,the release rate oftwo drugs was different.These results indicated that ultrasound irradiation was a facile method torealize the on-demand controlled release of two drugs from the electrospun fibers.展开更多
文摘Superhydrophobic poly(vinylidene fluoride) PVDF-SiO2 composite membranes with different % of SiO2 contents were prepared by electrospinning. The surface morphologies of the membranes are characterized by using scanning electron microscopy. The nanofibers in the membranes were stacked in layers to produce fully interconnected pores that resulted in high porosity. The incorporation of SiO2 into the nanofiber membrane improved the ionic conductivity from 0.2428 × 10-4Scm-1 to 7.731 × 10-4Scm-1 at room temperature. The surface roughness of the membranes increased with increasing the SiO2 content, while the average diameter of nanofibers was rarely affected. Superhydrophobic PVDF membrane with a contact angle larger than 136° was prepared by the electrospinning of the SiO2 functionalized PVDF. The surface composition of the membranes is analyzed by using FTIR and the contact angles and water drops on the surface of the membrane are measured. The contact angle experimental results of PVDF-SiO2 composite membranes showed an improvement of hydrophobicity with % of nano SiO2.
基金supported by China-USA cooperation for 10+10 program (No. 2009DFA90740),Ministry of Science and Technologysponsored by Science & Technology Commission,Shanghai
文摘Novel amino （-NH2） functionalized mesoporous polyvinyl pyrrolidone （PVP）/SiO2 composite nanofiber membranes were fabricated by a one-step electrospinning method using poly （vinyl alcohol） and tetraethyl orthosilicate （TEOS） mixed with cationic surfactant, cety｜trimethyl ammonium bromide （CTAB） as the structure directing agent. Ureidopropyltriethoxysilane was used for functionalization of the internal pore surfaces. The membranes were characterized by scanning electron microscopy （SEM）, high-resolution transmission electron microscopy （HRTEM） images, X-ray diffraction （XRD）, Fourier-transform infrared spectroscopy （FT-IR）, element analyzer and Nz adsorption-desorption isotherms, The nanofiber diameters, average pore diameters and surface areas were 100-700 nm, 2.86 nm and 873,62 m2/g, respectively. These mesoporous membranes functionalized with -NH2 groups exhibited very high adsorptions properties based on the adsorption of Cr3＋ from an aqueous solution. Equilibrium adsorption was achieved after approximately 20 rain and more than 97% of chronium ions in the solution were removed. The membrane could be regenerated through acidification.
文摘Nanometer materials include roughly nanoparticle,nanotube, nanowire, nanofiber, nanofilm and nanoblock, among which nanofiber is defined as material with nanometer-sized diameter and longer than 1 micron in length. The research development of polymer nanofibers, including manufacture methods and properties of some polymer nanofibers as well as their potential applications is reviewed.
基金the financial supports from the Natural Science Foundation of Hunan Province in China (2018JJ1036)the Innovation Program of Central South University (2017CX001)
文摘Niobium pentoxide(Nb2O5) has been extensively studied as anode materials for lithium ion batteries(LIBs) due to its good rate performance and safety advantages.However, the intrinsic low electronic conductivity has largely restricted its practical application. In this work, we report the construction of mesoporous T-Nb2O5 nanofibers by electrospinning followed by heat treatment in air. The interconnected mesoporous structure ensures a high surface area with easy electrolyte penetration. When used as anodes for LIBs, the mesoporous Nb2O5 electrode delivers a high reversible specific capacity of 238 mA h g-1 after 1,000 cycles at a current density of 1 A g-1 within a voltage range of 0.01–3.0 V.Even at a higher discharge cut-off voltage window of 1.0–3.0 V, it still possesses a high reversible capacity of166 mA h g-1 after 200 cycles. Moreover, the porous Nb2O5 electrode also exhibits excellent rate capability. The enhanced electrochemical performances are attributed to the synergistic effects of porous nanofiber structure and unique crystal structure of T-Nb2O5, which has endowed this material a large electrode-electrolyte contact area with improved electronic conductivity.
基金funded by the National Natural Science Foundation of China(Grants No.51822202,52173233 and 51772050)Innovation Program of Shanghai Municipal Education Commission(Grant No.2021-01-07-00-03-E00109)+8 种基金Science and Technology Commission of Shanghai Municipality(Grant No.19520713200)Shanghai Scientific and Technological Innovation Project(Grant No.19JC1410400)“Shuguang Program”supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission(Grant No.20SG33)Key Basic Research Program of Science and Technology Com-mission of Shanghai Municipality(Grant No.20JC1415300)DHU Distinguished Young Professor Program and Fundamental Research Funds for the Central Universitiesthe Fundamental Research Funds for the Central Universities(Grant No.2232020D-02)Shanghai Sailing program(Grant No.20YF1400500)Shanghai Natural Science Foundation(Grant No.20ZR1401500)the Opening Project of Key Laboratory of Inorganic Functional Materials and Devices,Chinese Academy of Sciences(KLIFMD202104).
文摘The use of linear amphiphilic block copolymers as templates is an important method for the preparation of mesoporous materials.However,the obtained assemblies are usually sensitive to synthetic conditions,which impedes the preparation of such mesoporous materials in certain environments.Herein,we report a universal strategy applying an amphiphilic multiarm triblock copolymer in the preparation of mesoporous metal oxide nanofibers(NFs)using one metal oxide(TiO_(2),ZrO_(2),WO_(3),CeO_(2)),or two(TiO_(2)/WO 3,TiO_(2)/ZrO_(2),TiO_(2)/CeO_(2))and three(TiO_(2)/WO_(3)/CuO)metal oxides as composites.The template consists of modified β-cyclodextrin as the center of the macromolecule which is attached sequentially to a block of polystyrene,poly(acrylic acid),and poly(ethylene oxide).Under electrospinning conditions,stable unimolecular micelles are formed and effectively co-assemble with metal ions to form fibrous nanostructures.As indicated by various characterization methods,the synthesized TiO_(2) and its derived composite NFs maintain a straight and continuous fibrous structure after calcination,and TiO_(2) NFs exhibit uniform mesopores of 10.8 nm in diameter and a large Brunauer-Emmett-Teller surface area of 143.3 m^(2)g^(−1).Benefiting from the characteristic structure,still present after modification,Pt-decorated mesoporous TiO_(2) NFs display excellent ability in the visible-light photocatalytic degradation of tetracycline,which is superior to the commercial P25 catalyst.This study reveals a promising strategy for the preparation of fibrous mesoporous metal oxides.
基金supported by the Young Elite Scientists Sponsorship Program by CAST (Grant No. 2017QNRC001)the National Natural Science Foundation of China (Grant No. 51402116)
文摘To promote the energy density of symmetric all-solid-state supercapacitors(SCs),efforts have been dedicated to searching for high-performance electrode materials recently. In this paper,vanadium nitride(VN) nanofibers with mesoporous structure have been fabricated by a facile electrospinning method. Their crystal structures and morphology features were characterized by X-ray diffraction,scanning electron microscopy,and transmission electron microscopy. The mesoporous structure of VN nanofibers,which can provide short electrolyte diffusion routes and conducting electron transport pathways,is beneficial to their performance as a supercapacitor electrode. Under a stable electrochemical window of 1.0 V,VN nanofibers possess an excellent mass specific capacitance of 110.8 F/g at a scan rate of 5 mV/s. Moreover,the VN nanofibers were further assembled into symmetric all-solid-state SCs,achieving a high energy density of 0.89 mW·h/cm^3 and a high power density of 0.016 W/cm^3 over an operating potential range from 0 to 1.0 V. These results demonstrate that VN nanofibers could be potentially used for energy storage devices.
文摘Sulfated zirconia/silica(SZ/SiO2) complex nanofibers were prepared by combining electronspinning technique and sol-gel method.First,a silica sol was electrospun at a voltage of 12 kV,then the as-electrospun silica nanofibers were immersed into a sulfated zirconia sol afterwards with a thermal treatment to obtain the SZ/SiO2 complex nanofibers.These fibers were examined by SEM,TEM,FTIR, XRD and SPS.The results indicate that the SZ nanopaticles with the average diameter of about 8 nm were disspered on the surface of silica fibers which had an average diameter of about 170 nm.The complex nanofibers had an amorphous structure.The observation of the surface-related transitions at the SPS spectrum indicates the presence of positive charges on the surface of the complex fibers.
基金This work was supported by grants from Natural Science Foundation of China(grant no.:3073003481190132).
文摘The aim of this study was to achieve on-demand controlled drug release from the dual-drug-loadedpoly(lactic-co-glycolic acid)/mesoporous silica nanoparticles electrospun composite fibers by theapplication of ultrasound irradiation.Two drugs were loaded in different part of the composite fibrousmaterials,and it was found that ultrasound as an external stimulus was able to control releaseof drugs due to both its thermal effect and non-thermal effect.With the selective irradiation ofultrasound,the drug carrier enabled to realize controlled release,and because of different locationin fibers and sensitivity of two different kinds of drugs to ultrasound irradiation,the release rate oftwo drugs was different.These results indicated that ultrasound irradiation was a facile method torealize the on-demand controlled release of two drugs from the electrospun fibers.
