电纺法制备TPU微/纳米纤维的研究进展

本文介绍了电纺热塑性聚氨酯(TPU)制备中所涉及熔融电纺法和溶液电纺法的研究现状,并综述了电纺TPU在医用支架材料、伤口敷料、锂电池电解质、形状记忆材料、吸声材料、压阻敏感性材料方面的应用研究进展。

锂离子二次电池用隔膜—微孔膜的研究

重点对锂离子电池用微孔膜常用的原料及加工工艺、电池对微孔膜的性能要求进行了阐述。对国内外锂离子电池隔膜的开发现状进行了研究,提出我国在电池隔膜方面必须加大研究和开发的力度,摆脱对进口电池隔膜的依赖。展望了未来锂离子电池的发展方向—聚合物锂离子电池,可以预测聚合物电解质膜将是今后锂离子电池隔膜的一个发展方向。

两步法合成ZnO／TiO2异质结构

采用电纺和水热处理两步法,通过水热后处理在电纺的TiO2纤维上生长了ZnO二级结构,制备了ZnO/TiO2异质结构的复合材料,并研究了反应时间对ZnO生长的影响。采用SEM,TEM对异质结构的微观结构进行了表征,XRD对ZnO/TiO2进行了物相分析。

电纺ZnO纳米线向纳米管的转变

本文提出了一种制备多孔ZnO纳米管的新而简易的方法，首次实现电纺ZnO纳米线向纳米管的转变。该方法利用普通电纺法获得的ZnO纳米线，再通过后续两步热处理制备：180℃～220℃一小时预处理，然后通过快速升温热处理至530℃保温5小时，有别于流行的Kirkendall成管机理。上述研究成果对于进一步探索新的纳米管生长机理具有重要学术价值。

Characterization of V_2O_5/MoO_3 composite photocatalysts prepared via electrospinning and their photodegradation activity for dimethyl phthalate

Vanadium pentoxide（V2O5）/molybdenum trioxide（MoO 3） composites with different molar ratios of vanadium（V） to molybdenum（Mo） were synthesized via a simple electrospinning technique. The photocatalytic activity of the composites were evaluated by their ability to photodegrade methylene blue and dimethyl phthalate（DMP） under visible-light irradiation. Compared with pure V2O5 and MoO 3,the V2O5/MoO 3 composites showed enhanced visible-light photocatalytic activity because of a V 3d impurity energy level and the formation of heterostructures at the interface between V2O5 and MoO 3. The optimal molar ratio of V to Mo in the V2O5/MoO 3 composites was found to be around 1/2. Furthermore,high-performance liquid chromatographic monitoring revealed that phthalic acid was the main intermediate in the photocatalytic degradation process of DMP.

Highly Responsive and Selective Ethanol Gas Sensor Based on Co3O4-Modified SnO2 Nanofibers

SnO2 nanofibers were synthesized by electrospinning and modified with Co3O4 via impregnation in this work. Chemical composition and morphology of the nanofibers were system- atically characterized, and their gas sensing properties were investigated. Results showed that Co3O4 modification significantly enhanced the sensing performance of SnO2 nanofibers to ethanol gas. For a sample with 1.2 mol% Co3O4, the response to 100 ppm ethanol was 38.0 at 300 ℃, about 6.7 times larger than that of SnO2 nanofibers. In addition, the response/recovery time was also greatly reduced. A power-law dependence of the sensor response on the ethanol concentration as well as excellent ethanol selectivity was observed for the Co3O4/SnO2 sensor. The enhanced ethanol sensing performance may be attributed to the formation of p-n heterojunctions between the two oxides.

Preparation of dual-shell Si/TiO_(2)/CFs composite and its lithium storage performance

A dual-shell Si/TiO2/CFs composite was synthesized through a simple method to deal with the intrinsic drawbacks of silicon-based anode,in terms of huge volume change,unstable SEI films,and low electronic and ionic conductivity.The inner rigid TiO2 shell alleviates the huge volume expansion of the nano silicon,and the outer resilient carbon fiber,which is porous and staggered,is beneficial to the rapid transport of electrons and ions.The as-prepared Si/TiO2/CFs composite displays a superior reversible specific capacity of 583.4 mA·h/g,high rate capability and decent cycling performance.The dual-shell encapsulation method provides a guideline for other anode materials with huge volume expansion during the cycling process.

Synthesis and acetone gas sensing properties of α-Fe_2O_3 nanotubes

α-Fe2O3 nanotubes was successfully prepared by single nozzle electrospinning method. Scanning electron microscope （SEM） was used to characterize the morphology of α-Fe2O3 nanotubes. The gas sensing properties of α-Fe2O3 nanotubes were investigated in detail. The results exhibit relatively good sensing properties to acetone at 240℃. The response and recovery times are about 3 and 5 s, respectively. The structure of nanotubes is beneficial to the gas sensing properties, which will enlarge the surface-to-volume ratio of α-Fe2O3 and then be available for the transfer of gas, and thus improved the sensor performance consequentially.

Synthesis of microporous membranes and films on various substrates by novel electrospinning method

The introduction of electrospinning technique in synthesis of supported microporous membranes and films opens bright pro- spects for mass production and practical applications. This novel and promising strategy has wide suitable range for various substrates with the possibility of large-area processing. We successfully synthesized several kinds of microporous materials into high quality membranes and films on different shaped supports by this method, such as zeolite NaA and pure-silica-zeolite Beta membranes on porous A1203 tube, zeolite NaY membrane on stainless steel net and a metal-organic framework Eu（BTC）（H20） DMF （JUC-32） film on porous silica disc. X-ray diffraction （XRD） and scanning electron microscopy （SEM） were used as characterization means. The results verified the effectiveness of this new approach in fabrication of membranes and films.

Stretchable electrothermochromic fibers based on hierarchical porous structures with electrically conductive dual-pathways

Stretchable color-changing fibers are urgently demanded for smart textiles/clothing due to their perfect implantability,permeability of vapor and heat,and flexibility/stretchability.Herein,stretchable electrothermochromic fibers were fabricated with unconventional stretchable conductive fibers as core layers and thermochromic coatings as shell layers.In the stretchable conductive fibers,hierarchical porous structures with percolative one-dimensional(1 D)conductive networks were constructed through phase inversion of carbon nanotube/polyurethane(CNT/PU)solutions.With the deposition of silver nanoparticles(AgN Ps)on the surface of micro-pores,electrically conductive dual-pathways consisting of0 D AgN Ps and 1 D CNTs were formed to significantly enhance the electric conductivity and thus improve the electrothermal performance of the fibers.More importantly,because of the connective CNTs and AgN Ps,such dual-pathways ensured the electron transport under the stretching state,preventing the sharp decay of conductivity and electrothermal performance.Through the continuous wet-spinning method,the stretchable conductive fibers can be easily obtained with the length up to several meters.At last,stretchable electrothermochromic fibers were prepared with two color-changing modes and implanted into textile perfectly,advancing their applications in wearable display and military adaptive camouflage of smart clothing.

Highly stretchable, electrically conductive textiles fabricated from silver nanowires and cupro fabrics using a simple dipping-drying method

In this study, we combined silver nanowires with cupro fabrics using a dipping- drying method to prepare electrically conductive fabrics. The silver nanowires were first adhered to and then absorbed by microfibers to form electrically conductive fibers. They also filled the gaps and spaces between the microfibers, and were stacked or piled together to form networks with high electrical conductivity. The electrically conductive fabric had low resistance and good stretchability, e.g., 0.0047-0.0091 Ωin the strain range of 0-190%. They also exhibited stable electrical conductivity, as well as excellent flexibility, which remained even when the fabric was stretched, shrunk, or bent. The results show that the electrically conductive fabric can be used as a smart textile, especially in fields associated with weaving, clothing, food products, lifestyle products, medicine, biology, electronics, aviation, and military equipment and accessories.

One-pot synthesis of Li_3VO_4@C nanofibers by electrospinning with enhanced electrochemical performance for lithium-ion batteries

Electrospinning is firstly used to one-pot synthesis of Li3VO4@C nanofibers in a large scale. Although with the presence of organic sources in synthesis process, the pure phase Li3VO4 with superior nanofibrous morphology is still successfully obtained through adjusting different heat treatment processes and different vanadium sources. The prepared Li3VO4@C nanofibers exhibit a unique structure in which nanosized Li3VO4 particles are uniformly embedded in amorphous carbon matrix. Compared with LiBVO4/C powder, Li3VO4@C nanofibers display enhanced reversible capacity of 451 mAhg^-1 at 40mAg^-1 with an increased initial coulombic efficiency of 82.3%, and the capacity can remain at 394 mAh g ^-1 after 100 cycles. This superior electrochemical performance can be attributed to its unique structure which ensures a high reactivity by nanosized Li3VO4, more stable electrode/electrolyte interface by carbon encapsulation, improved electronic conductivity and buffered volume changes by flexible carbon matrix. The electrospinning technology provides an effective method to obtain high performance Li3VO4 as a promising anode material for lithium-ion batteries.