A separator film for high-performance Li-ion batteries was prepared by electrospinning. The film had a hybrid morphology of silica nanofibers(SNFs) and alumina nanoparticles(ANPs), with a smooth surface, polymer-free ...A separator film for high-performance Li-ion batteries was prepared by electrospinning. The film had a hybrid morphology of silica nanofibers(SNFs) and alumina nanoparticles(ANPs), with a smooth surface, polymer-free composition, high porosity(79%), high electrolyte uptake(876%), and excellent thermal stability. Contact angle measurements demonstrated the better immersion capability of the SNF-ANP separator film for commercial liquid electrolytes than a commercial CELGARD 2500 separator film. Moreover,compared to the commercial CELGARD 2500 separator, the ionic conductivity of the SNF-ANP separator film was nearly three times higher, the bulk resistance was lower at elevated temperature(120 ℃), the interfacial resistance with lithium metal was lower, and the electrochemical window was wider. Full cells were fabricated to determine the cell performance at room temperature. The specific capacity of the full cell with the SNF-ANP separator film was 165 mAh g-1;the cell was stable for 100 charge/discharge cycles and exhibited a capacity retention of 99.9%. Notably, the electrospun SNF-ANP separator film can be safely used in Li-ion or Li-S rechargeable batteries.展开更多
Electrospun porous films doped with the green-synthesized CdSe quantum dots were synthesized. Glycerol was chosen to prepare the quantum dots （ QDs）, with the highest quantum yield of 78.28%. Polycaprolactone （PCL...Electrospun porous films doped with the green-synthesized CdSe quantum dots were synthesized. Glycerol was chosen to prepare the quantum dots （ QDs）, with the highest quantum yield of 78.28%. Polycaprolactone （PCL） was electrospun with CdSe QDs to avoid the QDs＇ toxicity and improve the QDs＇ cytocompatibility. The electrospun QDs-doped films preserve the original QDs＇ fluorescence. Pores can be detected from the SEM of the films, predicting the possibility of loading drugs in the cancer therapy. The cell proliferation assay shows excellent cytocompatibility of the eletrospun CdSe-QDs-doped films. The present eletrospun CdSe- QDs-doped porous films are cytocompatibale, highly-fluorescent and ootential to load drugs in cancer therapy.展开更多
This study proposes a facile, but precise method to back-calculate the effective modulus of nanocomposite interleaving plies. Adaptation of a conventional dry-reinforcement resin film infusion (RFI) approach allows in...This study proposes a facile, but precise method to back-calculate the effective modulus of nanocomposite interleaving plies. Adaptation of a conventional dry-reinforcement resin film infusion (RFI) approach allows interleaving neat epoxy layers (NE) with the epoxy-infused nanofibrous plies (XE) of constant thickness. The final cured nanocomposite laminate thus has the form (NE/XE)n, where “n” denotes the number of the repeats and enables clear distinction of the nanocomposite interlayers through the thickness. Mechanical testing of neat epoxy and laminated nanocomposite specimens can be coupled with the classical lamination theory for back-calculating in-plane elastic modulus of the individual epoxy-infused nanofibrous plies (EXE). Finite element analysis (FEA) and testing the laminated nanocomposite subject to flexural loading (3-point bending) are proposed to validate the analytically back-calculated EXE. It is shown that the FEA prediction incorporating EXE and testing for flexural modulus of (NE/XE)20 laminated nanocomposites correlate well and the results are within 5%. This finding suggests that the back-calculation scheme reported herein would be attractive for accurately determining the properties of an individual nanocomposite building block layer. The proposed framework is beneficial for modelling laminated structural composites incorporating XE-like nanocomposite interlayers.展开更多
It is still a challenge to prepare a water-and polymer-based electrospun air filter film with high efficiency filtration,low pressure drop,and good mechanical properties.To address this issue,polyvinyl alcohol(PVA)was...It is still a challenge to prepare a water-and polymer-based electrospun air filter film with high efficiency filtration,low pressure drop,and good mechanical properties.To address this issue,polyvinyl alcohol(PVA)was employed as the main material,mixing polyethyleneimine(PEI),bamboo-based activated carbon(BAC)and cellulose nanocrystal(CNC)to construct the air filter film by electrostatic electrospinning.In this system,the negatively charged BAC and CNC are fixed in the system through bonding with the positively charged PEI,showing a double adsorption effect.One is the mechanical filtration of the porous network structure constructed by PVA@PEI electrospun nanofibers,and the other is the electrostatic adsorption of PM2.5 on the surface of BAC and CNC.It is significant that the resulting composite air filter displays a high filtration efficiency of 95.86%,a pressure drop of only 59 Pa,and good thermal stability.Moreover,the introduced methyltrimethoxysilane(MTMS)endows it with good water-resistance.Given these excellent performances,this system can provide theoretical and technical references for the development of water-and polymerbased electrospun air filter film.展开更多
Adult central nervous system （CNS） tissue has a limited capacity to recover after trauma or disease. Recent medical cell therapy using polymeric biomaterial- loaded stem cells with the capability of differentiation ...Adult central nervous system （CNS） tissue has a limited capacity to recover after trauma or disease. Recent medical cell therapy using polymeric biomaterial- loaded stem cells with the capability of differentiation to specific neural population has directed focuses toward the recovery of CNS. Fibers that can provide topographical, biochemical and electrical cues would be attractive for directing the differentiation of stem cells into electro-responsive cells such as neuronal cells. Here we report on the fabrication of an electrospun polypyrrole/polylactide composite nanofiber film that direct or determine the fate of mesenchymal stem cells （MSCs）, via combination of aligned surface topography, and electrical stimulation （ES）. The surface morphology, mechanical properties and electric properties of the film were characterized. Comparing with that on random surface film, expression of neurofilament-lowest and nestin of human umbilical cord mesenchymal stem cells （huMSCs） cultured on film with aligned surface topography and ES were obviously enhanced. These results suggest that aligned topography combining with ES facilitates the neurogenic differentiation of huMSCs and the aligned conductive film can act as a potential nerve scaffold.展开更多
基金financial support for this work from the National Key R&D Program of China (2016YFB0100100)the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDA17000000)R&D Projects in Key Areas of Guangdong Province of the Guangdong Provincial Department of Science and Technology Agency (2019B090908001).
文摘A separator film for high-performance Li-ion batteries was prepared by electrospinning. The film had a hybrid morphology of silica nanofibers(SNFs) and alumina nanoparticles(ANPs), with a smooth surface, polymer-free composition, high porosity(79%), high electrolyte uptake(876%), and excellent thermal stability. Contact angle measurements demonstrated the better immersion capability of the SNF-ANP separator film for commercial liquid electrolytes than a commercial CELGARD 2500 separator film. Moreover,compared to the commercial CELGARD 2500 separator, the ionic conductivity of the SNF-ANP separator film was nearly three times higher, the bulk resistance was lower at elevated temperature(120 ℃), the interfacial resistance with lithium metal was lower, and the electrochemical window was wider. Full cells were fabricated to determine the cell performance at room temperature. The specific capacity of the full cell with the SNF-ANP separator film was 165 mAh g-1;the cell was stable for 100 charge/discharge cycles and exhibited a capacity retention of 99.9%. Notably, the electrospun SNF-ANP separator film can be safely used in Li-ion or Li-S rechargeable batteries.
基金Shanghai Leading Academic Discipline Project,China，Shanghai Key Laboratory Project,China，Doctoral Fund of Ministry of Education of China，National Natural Science Foundation of China
文摘Electrospun porous films doped with the green-synthesized CdSe quantum dots were synthesized. Glycerol was chosen to prepare the quantum dots （ QDs）, with the highest quantum yield of 78.28%. Polycaprolactone （PCL） was electrospun with CdSe QDs to avoid the QDs＇ toxicity and improve the QDs＇ cytocompatibility. The electrospun QDs-doped films preserve the original QDs＇ fluorescence. Pores can be detected from the SEM of the films, predicting the possibility of loading drugs in the cancer therapy. The cell proliferation assay shows excellent cytocompatibility of the eletrospun CdSe-QDs-doped films. The present eletrospun CdSe- QDs-doped porous films are cytocompatibale, highly-fluorescent and ootential to load drugs in cancer therapy.
文摘This study proposes a facile, but precise method to back-calculate the effective modulus of nanocomposite interleaving plies. Adaptation of a conventional dry-reinforcement resin film infusion (RFI) approach allows interleaving neat epoxy layers (NE) with the epoxy-infused nanofibrous plies (XE) of constant thickness. The final cured nanocomposite laminate thus has the form (NE/XE)n, where “n” denotes the number of the repeats and enables clear distinction of the nanocomposite interlayers through the thickness. Mechanical testing of neat epoxy and laminated nanocomposite specimens can be coupled with the classical lamination theory for back-calculating in-plane elastic modulus of the individual epoxy-infused nanofibrous plies (EXE). Finite element analysis (FEA) and testing the laminated nanocomposite subject to flexural loading (3-point bending) are proposed to validate the analytically back-calculated EXE. It is shown that the FEA prediction incorporating EXE and testing for flexural modulus of (NE/XE)20 laminated nanocomposites correlate well and the results are within 5%. This finding suggests that the back-calculation scheme reported herein would be attractive for accurately determining the properties of an individual nanocomposite building block layer. The proposed framework is beneficial for modelling laminated structural composites incorporating XE-like nanocomposite interlayers.
基金the China Postdoctoral Science Foundation(No.2021M692806)the Natural Science Foundation of Zhejiang Province(No.LY21C160002)the Scientific Research Development Foundation of Zhejiang A&F University(No.2018FR054).
文摘It is still a challenge to prepare a water-and polymer-based electrospun air filter film with high efficiency filtration,low pressure drop,and good mechanical properties.To address this issue,polyvinyl alcohol(PVA)was employed as the main material,mixing polyethyleneimine(PEI),bamboo-based activated carbon(BAC)and cellulose nanocrystal(CNC)to construct the air filter film by electrostatic electrospinning.In this system,the negatively charged BAC and CNC are fixed in the system through bonding with the positively charged PEI,showing a double adsorption effect.One is the mechanical filtration of the porous network structure constructed by PVA@PEI electrospun nanofibers,and the other is the electrostatic adsorption of PM2.5 on the surface of BAC and CNC.It is significant that the resulting composite air filter displays a high filtration efficiency of 95.86%,a pressure drop of only 59 Pa,and good thermal stability.Moreover,the introduced methyltrimethoxysilane(MTMS)endows it with good water-resistance.Given these excellent performances,this system can provide theoretical and technical references for the development of water-and polymerbased electrospun air filter film.
文摘Adult central nervous system （CNS） tissue has a limited capacity to recover after trauma or disease. Recent medical cell therapy using polymeric biomaterial- loaded stem cells with the capability of differentiation to specific neural population has directed focuses toward the recovery of CNS. Fibers that can provide topographical, biochemical and electrical cues would be attractive for directing the differentiation of stem cells into electro-responsive cells such as neuronal cells. Here we report on the fabrication of an electrospun polypyrrole/polylactide composite nanofiber film that direct or determine the fate of mesenchymal stem cells （MSCs）, via combination of aligned surface topography, and electrical stimulation （ES）. The surface morphology, mechanical properties and electric properties of the film were characterized. Comparing with that on random surface film, expression of neurofilament-lowest and nestin of human umbilical cord mesenchymal stem cells （huMSCs） cultured on film with aligned surface topography and ES were obviously enhanced. These results suggest that aligned topography combining with ES facilitates the neurogenic differentiation of huMSCs and the aligned conductive film can act as a potential nerve scaffold.
