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              UCALERY-Electrospinning

              随着静电纺丝技术的不断优化,电纺设备的不断升级,ucalery 电纺丝机所发的文章在数量和质量上不断突破。 基于这种情况, 让我们必须对自己有更高的要求来回馈支持我们的客户。编者对近来使用 ucalery 电纺丝机所发的文章进行了总结,摘取其中几篇好文章,供

              读者思考,希望给您的实验带去一丝灵感和启发。

              General synthesis of complex nanotubes by gradient electrospinning and controlled pyrolysis

              Abstract:Nanowires and nanotubes have been the focus of considerable efforts in energy storage and solar energy conversion because of their unique properties. However, owing to the limitations of synthetic methods, most inorganic nanotubes, especially for multi-element oxides and binary-metal oxides, have been rarely fabricated. Here we design a gradient electrospinning and controlled pyrolysis method to synthesize various controllable 1D nanostructures, including mesoporous nanotubes, pea-like nanotubes and continuous nanowires. The key point of this method is the gradient distribution of low-/middle-/high-molecular-weight poly(vinyl alcohol) during the electrospinning process. This simple technique is extended to various inorganic multi-element oxides, binary-metal oxides and single-metal oxides. Among them, Li 3 V 2 (PO4) 3 ,Na 0.7 Fe 0.7 Mn 0.3 O 2 and Co 3 O 4 mesoporous nanotubes exhibit ultrastable electrochemical performance when used in lithium-ion batteries, sodium-ion batteries and supercapacitors,respectively. We believe that a wide range of new materials available from our composition gradient electrospinning and pyrolysis methodology may lead to further developments in research on 1D systems.

              解读:这篇文章是武汉理工大学麦立强教授课题组在复杂纳米管可控制备及储能应用方面研究取得的最新成果,它发表在《Nature Communications》上,也是 ucalery 电纺丝机第一次登上 Nature 子刊。纳米线和纳米管因其独特的性质在能源存储和太阳能电池等领域引起了广泛关注。然而,由于传统合成方法的局限性,多数无机纳米管,尤其是多元素氧化物和双金属氧化物纳米管,却鲜见报道。麦立强教授课题组率先提出采用一种梯度静电纺丝技术和可控热解相结合的方法,可控制备了多种一维复杂纳米结构。该策略的关键点在于静电纺丝过程中,实现并证明了三种不同分子量的聚乙烯醇沿径向的梯度分布。这种简便的合成策略具有普适性,通过调节不同的烧结过程,可以制备出多种无机多金属氧化物、双金属氧化、单金属氧化物等的介孔纳米管和豌豆状纳米管。获得的介孔纳米管材料在锂离子电池、钠离子电池和超级电容器方面的应用,均具有优异的电化学性能。该工作首次提出通过采用不同分子量的同一聚合物来实现静电纺丝过程中的梯度分布,提供了一种有效的策略来可控制备复杂纳米管,在储能领域及其他领域均具有重要的科学意义和巨大的应用潜力。

              Nature Communications 创刊于 2010 年 4 月,是 Nature 杂志旗下在线多学科研究期刊,内容广泛涵盖了生物学、物理学、化学、材料学和地球科学等领域,刊登每个领域最重要及最有影响力的科研进展。

              文献出处:Chaojiang Niu,Jiashen Meng,Xuanpeng Wang,Chunhua Han,Mengyu Yan, Kangning Zhao,XiaomingXu,Wenhao Ren,Yunlong Zhao,Lin Xu,Qingjie Zhang,Dongyuan Zhao& Liqiang Mai,Nature Communications2015,6, 7402

              影响因子:11.470

              Fabrication of nanofibers with phase-change core and hydrophobic shell, via coaxial electrospinning using nontoxic solvent

              Abstract:Compared to phase-change fibers with hydrophilic polymer shell, those with hydrophobic polymer are more stable in water and moist environments. However, their fabrication processes are involved in some toxic organic solvents. Here, the nanofibers with phase-change material (PCM, i.e., octadecane) as core and hydrophobic shell (i.e., polyvinyl butyral) are fabricated via coaxial electrospinning using environmental friendly ethanol as solvent. Effects of the polyvinyl butyral concentration in ethanol solution as well as the flow rates of core and shell fluids on the morphology of octadecane/polyvinyl butyral (PCM/PVB) nanofibers are systematically investigated. The thermo-regulating capability of PCM/PVB nanofibers is demonstrated by observing the surface and inner temperatures of model houses covered with fibers. The higher the PVB concentration and the shell flow rate are, the better the morphology of core/shell PCM/PVB nanofibers becomes, leading to higher encapsulation efficiency. At a constant shell flow rate, the encapsulation ratio of PCM/PVB nanofibers increases with the core flow rate. The encapsulation ratio of the PCM/PVB nanofibers, which fabricated with PVB concentration of 20 % (w/v) and at the core flow rate of 0.60 ml h and the shell flow rate of 3.0 ml

              h, respectively, reaches to the maximum of 46.4 %. The corresponding melting enthalpy (Δ H) and the crystallization enthalpy (Δ H) of these PCM/PVB nanofibers are 105.9 and 106.5 J g, respectively. The PCM/PVB nanofibers exhibit good thermo-regulating capability under the simulated solar irradiation, regulating the temperature at around 28 °C. The resultant PCM/PVB nanofibers exhibit satisfactory stabi lit y an d rep eat abi lity in the thermo-regulating capability during repeated heating/cooling cycles. The results provide valuable guidance for environmental friendly preparation of phase-change nanofibers with satisfactory and stable thermal characteristics.

              解读:亲水性聚合物为壳的相变纤维在水和潮湿的环境中稳定性往往较差,而疏水性聚合物其稳定性较好,但制造过程需要使用一些有毒的有机溶剂。因此,作者以相变材料 PCM 为芯层,具有疏水性的 PVB 材料为壳层, 利用环境友好的乙醇作溶剂进行同轴静电纺丝。 同轴静电纺丝是静电纺丝的一个重要内容, ucalery的纺丝机可以通过分别控制壳-芯的纺丝速度达到最佳纺丝效果。当壳层的纺丝速度恒定,PCM / PVB 纳米纤维的包封率随着核层纺丝速度的增大而增大。当 PVB 浓度为 20%,核层流速为 0.60ml/h, 壳层流速为 3.0ml/h 时,PCM / PVB 纳米纤维的包封率高达 46.4%,纳米纤维相应的熔化焓和结晶焓分别为 105.9J/g 和 106.5J/g。实验结果表明该 PCM / PVB 纳米纤维具有良好的热调节能力, 所得的 PCM / PVB 纳米纤维在反复加热/冷却循环过程中其热调节能力表现出令人满意的稳定性和可重复性。这一结果为环境友好型的相变纳米纤维提供了宝贵的指导意见。

              文 献 出 处 Shao-Xing Sun,Rui Xie,Xiao-Xue Wang, Guo-Qing Wen, Zhuang Liu,Wei Wang, Xiao-JieJu,Liang-Yin Chu.Journal of Materials Science 2015, 50 (17):5729-5738

              影响因子:2.371

              Enhanced chromium (VI) adsorption using nanosized chitosan fibers tailored by electrospinning

              Abstract: Stacked chitosan nanofibers with an average diameter of 75 nm were successfully produced by electrospinning using 5 wt% chitosan in acetic acid as the spinning solution. The fibers were then cross-linked with glutaraldehyde to remove chromium [Cr(VI)] from water via static adsorption. It was found that the adsorption correlated well with pseudo-second order kinetic model, and followed a mixed isotherm of Freundlich and Langmuir. The maximum nanofibers adsorption capacity was 131.58 mg/g, more than doubled that of chitosan powders. Common co-ions such as Cl−, NO3−, Na+, Ca2+ and Mg2+ had little or no effect on the adsorption but SO42− was an exception. Fourier transform infrared spectroscopy and X-ray photoelectron spectrophotometer analyses indicated that both amino and hydroxyl groups of chitosan were engaged in the adsorption.

              解读:六价铬是一种致癌物,其对人体具有诱变性,致癌性和致畸性,被美国环境保护署(EPA)定为一级有毒污染物。世界卫生组织和美国环保局推荐一般饮用水中最大容许的铬浓度是 0.05 或 0.1mg/L,并且世界各国都对其有着的严格监管。在许多情况下,去除水中的污染物不仅是必要的而且是有严格规定的,许多水处理的技术已经得到很好地开发,包括降水,吸附,离子交换,反渗透,电渗析等。其中,吸附可以更彻底地消除金属,是一个最简单的和节约成本的方法。这篇文章以壳聚糖和乙酸配成浓度为 5 wt %的纺丝溶液,利用静电纺丝方法成功制备多层壳聚糖纳米纤维。该纤维随后与戊二醛交联,通过静态吸附去除水中的铬。利用静电纺丝机成功制备出均匀的壳聚糖纳米纤维,纤维平均直经仅 75nm,同时壳聚糖的纺丝难度较大,因此这对电纺设备有较高的要求。而最后所有的结果均显示该壳聚糖纳米纤维在吸附去除铬方面具有很大前景。例如:使用纳米纤维交联的戊二醛对水中铬(VI)的最大吸附容量是使用脱乙酰壳多糖粉末最大吸附容量的一倍多。 而更进一步的工作需要研究如何更有效的收集纤维和更适当的方式来使用这些纤维,以保持纤维的表面积大和更优良的性能,从而实现对饮用水中重金属的去除。

              文献出处:Lei Li,Yanxiang Li,Lixia Cao,Chuanfang Yang.Carbohydrate Polymers 2015,125 (206–213)

              影响因子:4.074

              Electrospun polymer nanofiber membrane electrodes and an electrolyte for highly flexible and foldable all-solid-state supercapacitors

              Abstract : A sandwiched symmetric all-solid-state supercapacitor consi sting of flexible electrospun polyaniline (PANI)/carbonized polyimide (CPI) nanocomposite membrane electrodes and a poly(vinyl alcohol) (PVA)/poly(acrylic acid) (PAA) nanofiber membrane-reinforced PVA/H3PO4 gel separator has been successfully fabricated. Needle-like PANI nanoparticles are vertically formed on the high electrically conductive three-dimensional CPI nanofiber network, resulting in an efficiently improved specific surface area of the PANI nanoparticles and faster electrolyte ion penetration and electron transfer in the active electrode material. The synergistic effect thus generates remarkably higher specific capacitance of 379 F g−1 at 0.5 A g−1 and longer cycle life with a retention of 94% at 1 A g−1 for PANI/CPI nanocomposite membrane electrodes, compared with those (209 F g−1, 56%) of neat PANI powder. Furthermore, electrospun PVA/PAA nanofiber membrane-reinforced PVA/H3PO4 gel separator exhibits superior mechanical properties over the traditional PVA/H3PO4 gel separator, thus endowing the entire device with high flexibility and foldability. Therefore, electrospinning is a very promising technique for the preparation of highly flexible and foldable electrode and separator materials with hierarchical structures in high-performance new energy storage applications

              解读:在各种不同的能量存储系统中,超级电容器已经受到广泛关注。本质上讲,高性能的灵活超级电容器很大程度上依赖于电极材料的创新,使它们具有良好的电气和机械性能,高功率/能量密度和优异的循环稳定性。由于聚苯胺(PANI)其易于合成,良好的环境稳定性,高电导率等特性使得其被广泛应用于聚合物电极材料。然而它也存在一些严重的问题,如体积变化大、循环性能差,聚苯胺作为电极材料应用于超级电容器中这些问题都是有待解决的。为了解决这个问题,结合赝电容材料与碳基材料是一种很有前途的的方式来实现的电化学双层电容器和赝电容材料的协同电化学。

              这篇文章利用静电纺丝技术成功的制备PANI/CPI纳米复合膜电极和PVA/PAA纳米纤维膜增强PVA/ H3 PO 4 凝胶。针状的 PANI 纳米颗粒垂直形成于 CPI 纳米纤维网络上,从而导致在活性电极材料中聚苯胺纳米颗粒的比表面积提高。该协同作用使 PANI/CPI 纳米复合膜电极产生高比电容和长循环寿命。因此,静电技术是一个非常有前途的制备电极和隔板材料的方法。

              文献出处:Yue-E Miao,Jiajie Yan,Yunpeng Huang,Wei Fan,Tianxi Liu,RSC Advances 2015,5, 26189-26196

              影响因子:3.84

              Phase separation in electrospun nanofibers controlled by crystallization induced self-assembly

              Abstract:Nanofibers from poly(lactic acid) (PLA) homopolymer and poly(p-dioxanone)-b-poly (ethy-lene glycol) multi-block copolymer (PPDO-b-PEG) with different phase separation morphologies depending on the crystallization induced self-assembly of PPDO-b-PEG are prepared by single spinneret electrospinning. Mixing solvents of chloroform-dimethyl formamide (CHCl3-DMF) with different compositions are used for controlling the crystallization of the PPDO block and therefore the phase separation in the obtained nanofibers. The crystallization of the PPDO block has a very important influence on the morphology of the PPDO-b-PEG nanoparticles in the spinning solution. In spinning solutions with low DMF content, nanoparticles with irregular shapes and non-compact inner structures are formed because the degree of crystallization of the PPDO block is relatively low, and a discontinuous sea-island phase separation is formed in the obtained electrospun nanofibers. Meanwhile, in spinning solutions with high DMF content, the copolymer can form flake-like nanoparticles with a relatively high degree of

              crystallization. The flake-like shape favors compact aggregation of the PPDO phase during formation of the nanofibers, and a continuous core-shell phase separation

              of the nanofibers is obtained.

              解读:具有纳米级尺寸的一维材料,如纳米线,纳米管和纳米纤维,在材料科学中是一种最重要和最有代表性的类别科学。而在制备一维材料的这些方法中,静电纺丝技术是较简单的一种。多层结构,例如核-壳相分离,在材料性能和功能上可能会导致许多有趣的变化,并且它还具有广阔的应用领域,如光学,传感器,催化,太阳能电池和许多其它领域。由 PLA 和 PPDO-B-PEG 进行同轴电纺丝,用不同组分的混合溶剂氯仿和DMF来控制PPDO基体中的结晶度从而达到相分离的目的。 PPDO基体的结晶度对PPDO-b-PEG纳米颗粒在纺丝溶液的形态有非常重要的影响。当纺丝溶液中 DMF 含量较低时,纳米颗粒具有不规则的形状。同时,当纺丝溶液中 DMF 含量较高时,共聚物可形成结晶度较高的片状纳米颗粒。在纳米纤维形成的过程中片状有利于 PPDO 相的致密聚集,可以得到连续的核-壳相分离纳米纤维。这篇文章对同轴电纺丝来说是很有意义的,日常实验中我们经常听大家反馈难以得到连续的核-壳相分离纳米纤维,而这篇文章就给我们指出了一些思路和方法,值得大家学习。

              文献出处: Wei Huang,Mei-Jia Wang,Chang-Lei Liu,Jiao You, Si-Chong Chen, Yu-Zhong Wang,Ya.Liu. journal of materials chemistry A 2014,2, 8416-8424

              影响因子:7.443

              Germanium nanoparticles encapsulated in flexible carbon nanofibers as self-supported electrodes for high performance lithium-ion batteries

              Abstract:Germanium is a promising high-capacity anode material for lithium ion batteries, but still suffers from poor cyclability due to its huge volume variation during the Li–Ge alloy/dealloy process. Here we rationally designed a flexible and self-supported electrode consisting of Genanoparticles encapsulated in carbon nanofibers (Ge–CNFs) by using a facile electrospinning technique as potential anodes for Li-ion batteries. The Ge–CNFs exhibit excellent electrochemical performance with a reversible specific capacity of 1420 mA h g −1 after 100 cycles at 0.15 C with only 0.1% decay per cycle (the theoretical specific capacity of Ge is 1624 mAh g −1 ). When cycled at a high current of 1 C, they still deliver a reversible specific capacity of 829 mA h g −1 after 250 cycles. The strategy and design are simple, effective, and versatile. This type of flexible electrodes is a promising solution for the development of flexible lithium-ion batteries with high power and energy densities.

              解读:可充电的锂离子电池已成为必不可少的便携式电子设备,如手机,笔记本电脑,数码相机,电动汽车。满足高能量和高功率是可逆容量电极材料的关键。GE 阳极材料由于其理论比容量高,具有优良的锂离子扩散系数和高电导率因此备受关注。然而,GE 作为阳极材料其循环性能较差,为了改善循环性能将纳米碳纤维包覆锗纳米颗粒。然而,由于制备<10nm 的锗纳米颗粒较复杂,因此得到包封在碳纳米纤维中高度分散的纳米颗粒仍然是一个挑战。这篇文章利用简单的静电纺丝技术合理地设计一个灵活的自支撑纳米碳纤维电极(GE-CNFs),作为锂离子电池的阳极材料,最终结果显示 GE-CNFS 表现出优异的电化学性能,灵敏的 GE-CNF 电极具有长期稳定的循环性能,良好的速度能力和较高的放电容量。但整个电极的容量性能有待进一步提高,而这个问题在未来可以通过增加锗含量和碳基体容量来解决。总的来说该设计简单,有效且用途广泛,这种具有高功率和能量密度的锂离子电池还是很有研究前景。

              文献出处:Weihan Li,Zhenzhong Yang,Jianxiu Cheng,Xiongwu Zhong, Lin Gu and Yan Yu .Nanoscale 2014,6,4532-4537

              影响因子:6.739

              Nanofibers with Very Fine Core-Shell Morphology fromAnisotropic Micelle ofAmphiphilic Crystalline-Coil Block Copolymer

              Abstract : A novel and facile strategy, combining anisotropic micellization of amphiphilic crystalline-coil copolymer in water and reassembly during single spinneret electrospinning, was developed for preparing nanofibers with very fine core–shell structure. Polyvinyl alcohol (PVA) and polyethylene glycol-block-poly(p-dioxanone) (PEG-b-PPDO) were used as the shell and the crystallizable core layer, respectively. The core–shell structure could be controllably produced by altering concentration of PEG-b-PPDO, and the chain length of the PPDO block. The morphology of the nanofibers was investigated by Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM). X-ray rocking curve measurements were performed to investigate the degree of ordered alignment of the PPDO crystalline lamellae in the nanofiber. The results suggested that the morphology of nanoparticles in spinning solution plays very important role in determining the phase separation of nanofibers. The amphiphilic PEG-b-PPDO copolymer self-assembled into star anise nanoaggregates in water solution induced by the crystallization of

              PPDO blocks. When incorporated with PVA, the interaction between PVA and PEG-b-PPDO caused a morphological transition of the nanoaggregates from star anise to small flake. For flake-like particles, their flat surface is in favor of compact stacking of PPDO crystalline lamellae and interfusion of amorphous PPDO in the core of nanofibers, leading to a relatively ordered alignment of PPDO crystalline lamellae and well-defined core–shell phase separation. However, for star anise-like nanoaggregates, their multibranched morphology may inevitably prohibit the compact interfusion of PPDO phase, resulting in a random microphase separation.

              解读:纳米纤维具有优秀的微结构,例如核-壳或多层同轴结构,因其不同的性能和功效而得到许多潜在的应用。各向异性纳米结构作为主要诱发力是特别有吸引力,因为它具有复杂的粒子相互作用。这篇文章主要把聚乙烯醇 (PVA) 用作壳层, (PEG-b-PPDO) 用作可结晶的核层。 核-壳结构可以通过改变 PEG-B-PPDO的浓度,以及 PPDO 的链长度而产生。经过实验表明,纺丝溶液中的纳米颗粒形貌在纳米纤维的相分离过程中起着非常重要的作用。 当与 PVA 结合, PVA 和 PEG-b-PPDO 之间的相互作用使纳米聚集体从八角形态过渡到小的片状。对于薄片状颗粒,其平整的表面有利于核层中的 PPDO 结晶层和 PPDO 非晶层的紧凑堆叠,导致 PPDO 结晶薄片和核-壳相分离的相对有序排列。然而,对于八角状纳米聚集体,其多分支的形态避免了 PPDO 相的混入,导致随机的微相分离。这本新型和简便的策略可以得到各种各样的具有核-壳结构的多功能纳米纤维。为核-壳结构的纳米纤维提供更多应用的空间。

              文献出处:Fei-Yu Zhai,Wei Huang,Gang Wu,Xin-Ke Jing,Mei-Jia Wang,Si-Chong Chen,Yu-Zhong Wang, In-Joo Chin, and Ya Liu.ACS Nano 2013, 7 (6):4892–4901

              影响因子:12.881

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