共查询到19条相似文献,搜索用时 156 毫秒
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高效、稳定、低成本可逆离子电池的研究对大型能源存储、便携电子设备、电动汽车、航空航天以及生态环境等领域的发展有着重大意义。可逆离子电池电极材料的微纳设计与结构调控是其高性能化的重要途径。静电纺丝制备功能微纳电极材料具有以下优势:(1)一维构筑单元有利于电子快速传导;(2)微纳化构筑单元具有短的离子扩散距离和高电极/电解液接触比表面积;(3)三维网络骨架结构可有效降低电极结构破坏。同时,通过调节静电纺丝体系参数可实现电极材料的结构、组分、尺寸、表面修饰、掺杂等参量可控制备。非金属(如Si、Ge)、金属(如Sn、Sb)以及过渡金属氧化物(如SnO_2、Fe_2O_3、Co_3O_4)、金属硫化物(如MoS_2、Co_9S_8)负极材料以及磷酸盐(如LiFePO_4、Li_3V_2(PO_4)_3)因具有高的理论比容量和能量密度等优点而被广泛地应用于超级电容器、离子电池(锂离子电池、钠离子电池、锂硫电池)等新一代储能器件中。然而,低导电性、高体积膨胀率等使得这类材料的倍率性能和使用寿命极大降低,制约了它们的商业化应用前景。基于碳材料(非晶碳、碳纳米管、石墨烯)以及导电聚合物设计制备不同微纳结构的碳基和聚合物基复合材料可有效解决以上难题,提高其储能性能。静电纺丝技术可以通过设计纺丝装置,调控纺丝前驱液的浓度,结合超声磁力搅拌促进纳米颗粒均匀分散以及高温热解等参量调控,有效制备得到自支撑纺丝碳基纤维复合材料。近年来,基于静电纺丝制备的柔性自支撑结构材料被广泛应用于能源存储领域,包括超级电容器、隔膜材料、离子电池等。然而,不同聚合物静电纺丝条件有较大差异,主要由聚合物的分子量大小、带电基团分布、亲疏水性、溶剂、溶液粘度等参量所决定。聚合物静电纺丝的前驱液主要为水溶性高分子与非水溶性高分子,溶剂通常为N,N-二甲基甲酰胺、乙醇等。聚合物与金属盐常被用于静电纺丝制备微纳复合纤维材料,通过调节纺丝参量(如聚合物溶液粘度、溶剂种类、电压、针尖与接收装置之间的距离、聚合物输运速率、温度以及湿度等)对其结构特性进行精确调控,实现储能容量和稳定性的双提升。本文将主要从以下几个方面介绍静电纺丝在可逆离子电池储能中的应用:静电纺丝技术进展,静电纺丝微纳材料在可逆离子电池中的应用,以及该领域研究的总结与展望。 相似文献
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离子液体具有优良的物理化学性能,受到研究者的广泛关注.近年来,有关离子液体在可逆加成-断裂链转移(RAFT)聚合反应中的应用有大量的研究报道.作为溶剂,离子液体能溶解一些较难溶解的聚合物,如纤维素和壳聚糖等,可以为聚合反应提供较好的反应环境;作为单体,通过RAFT聚合可制备出聚合离子液体均聚物或带有聚合离子液体链段的嵌段聚合物,可以应用于燃料电池电解质膜、太阳能电池、催化、分离及吸附剂等领域;离子液体还可以作为表面活性剂,应用于RAFT的乳液聚合或细乳液聚合,有效地稳定和控制聚合物颗粒大小.从溶剂、单体和表面活性剂方面出发,简单总结了离子液体在RAFT聚合反应中的应用. 相似文献
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近年来,关于丙烯酸酯类树脂吸附芳香有机化合物的研究受到越来越多的关注,研究表明,它们在非极性溶剂中的吸附主要表现为氢键作用力,这种作用力受吸附质分子的功能基团类型、位置和空间构型等因素的影响。而在极性溶剂水溶液中,它们之间的作用力则更加复杂,吸附质分子的亲水和疏水部分与吸附剂的骨架和功能基团之间的作用力都对吸附过程有着重要的贡献。文章还对今后的研究方向作了展望。 相似文献
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A simple new methodology to preapre 3-dimensional (3D) porous scaffold of biodegradable polymer was exploited by using hydrophilic types of ionic liquids. The mixture of poly(lactic acid) (PLA) and ionic liquid within dichloromethane solvent was phase-separated during the solvent evaporation, after which the ionic liquid phase was selectively extracted to provide interconnected macropores. The pore sizes of the PLA scaffold were highly dependent on the types of ionic liquids (anion variant), ranging from tens to hundreds of micrometers, and the porosity reached to ~ 85-95%. The ionic liquid-directed technique to prepare porous structure reported for the first time herein will be highly effective in the development of polymer skeletons for tissue engineering biomaterials. In addition, the ionic liquids recovered by a simple extraction with ethanol or water can be reused for subsequent runs without the loss of its physicochemical properties. 相似文献
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Conventional synthesis of inorganic materials relies heavily on water and organic solvents. Alternatively, the synthesis of inorganic materials using, or in the presence of, ionic liquids represents a burgeoning direction in materials chemistry. Use of ionic liquids in solvent extraction and organic catalysis has been extensively studied, but their use in inorganic synthesis has just begun. Ionic liquids are a family of non‐conventional molten salts that can act as templates and precursors to inorganic materials, as well as solvents. They offer many advantages, such as negligible vapor pressures, wide liquidus ranges, good thermal stability, tunable solubility for both organic and inorganic molecules, and much synthetic flexibility. In this Review, the use of ionic liquids in the preparation of several categories of inorganic and hybrid materials (i.e., metal structures, non‐metal elements, silicas, organosilicas, metal oxides, metal chalcogenides, metal salts, open‐framework structures, ionic liquid‐functionalized materials, and supported ionic liquids) is summarized. The status quo of the research field is assessed, and some future perspectives are furnished. 相似文献
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综述了离子液体的种类、合成及纯化方法。离子液体的纯度对其物理化学性质至关重要,是研究其应用的首要问题。本文介绍了离子液体的合成方法,并对比了其优缺点,发现合成方法对离子液体的纯度起着关键作用,指出了影响离子液体纯度的因素,分析对比了离子液体的纯化方法,包括真空干燥、有机溶剂萃取、重结晶、吸附剂法、分子筛法等,根据影响因素种类的不同,优选纯化方法,并对离子液体的发展进行了展望。 相似文献
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Technologies for the removal of phenol from fluid streams: a short review of recent developments 总被引:11,自引:1,他引:11
The available technologies for the abatement of phenol from water and gaseous streams are briefly reviewed, and the recent advancements summarized. Separation technologies such as distillation, liquid–liquid extraction with different solvents, adsorption over activated carbons and polymeric and inorganic adsorbents, membrane pervaporation and membrane–solvent extraction, have been discussed. Destruction technologies such as non-catalytic, supercritical and catalytic wet air oxidation, ozonation, non-catalytic, catalytic and enzymatic peroxide wet oxidation, electrochemical and photocatalytic oxidation, supercritical wet gasification, destruction with electron discharges as well as biochemical treatments have been considered. As for the abatement of phenol from gases, condensation, absorption in liquids, adsorption on solids, membrane separation, thermal, catalytic, photocatalytic and biological oxidation have also been considered. The experimental conditions and the performances of the different techniques have been compared. 相似文献
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气凝胶具有三维纳米多孔网络结构,独特的结构使它具有低密度、高比表面积和高孔隙率等性质以及低热导率、低介电常数和低声传播速率等性能,在隔热、介电、隔声、催化、吸附等领域具有广阔的应用前景.然而,溶剂-凝胶法作为目前制备气凝胶最成熟、应用最广的技术,需要使用大量的有机溶剂,严苛而危险的超临界干燥工艺进一步推高了成本,限制了气凝胶的大规模工业化生产和应用,因此,降低成本和在常压干燥条件下制备高比表面积的块状气凝胶是气凝胶产业急需解决的问题.离子液体被称为21世纪的绿色溶剂,具有低蒸气压、低表面张力、高催化性和高溶解性等特殊性质.离子液体与气凝胶材料的发展几乎同步,但直到2000年两种材料才产生交集.离子液体作为模板剂具有微观结构导向作用,使纳米孔结构均一化,其不挥发性和低表面张力保证了老化和常压干燥过程中纳米孔结构不会因毛细管力而坍塌破坏,另外其催化作用可以缩短凝胶时间.因此,离子液体为常压干燥合成气凝胶提供了新的工艺路线.目前,有关借助离子液体制备 SiO2气凝胶、TiO2气凝胶、SiO2-TiO2复合气凝胶、炭气凝胶等无机气凝胶的探索均已展开,其中制备 SiO2气凝胶的研究最多,涉及工艺、微观结构、掺杂和应用等方面.通过常压干燥可获得比表面积高达677 m2/g 的块状气凝胶,通过选用不同的离子液体还可以控制纳米孔的微观形貌,所得 SiO2气凝胶产物在电化学、生物、吸附等领域有较高的应用潜力.利用离子液体替代有机溶剂可以使得到的TiO2气凝胶不经煅烧即含有锐钛矿相,通过金属原子 Ag、Fe、Ge等掺杂改性,可进一步提高锐钛矿相的结晶度,提升其光催化性能.利用离子液体制得的 SiO2-TiO2复合气凝胶具有一定强度和良好的光催化活性.此外,除在传统的溶胶-凝胶法中用作模板剂或催化剂外,离子液体还可作为新型的炭源用于制备炭气凝胶,即通过熔盐法高温炭化裂解离子液体"自上而下"直接制备.这种方法可以制备杂原子在原子水平上均匀分布的功能化炭气凝胶,无需制备有机气凝胶前驱物,极大缩短制备周期,并且炭气凝胶产物的比表面积相对更高,得到了科研界的广泛关注. 相似文献
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为了减少钢铁冶金酸洗过程中酸液对不锈钢或碳钢的过腐蚀,得到高效的新型缓蚀剂材料,利用失重法、电化学法及扫描电子显微镜(SEM)等研究了不同浓度离子液体[HMIM]BF_4对HP13Cr不锈钢以及A3碳钢在1 mol/L盐酸溶液中的缓蚀特性和吸附行为。失重试验得出,试样在1 mol/L盐酸溶液中的腐蚀速率随离子液体添加浓度的增大而减小,即离子液体缓蚀效率随其浓度增加而增大;SEM结果显示,盐酸溶液中离子液体的添加对不锈钢HP13Cr以及碳钢A3均能起到显著的保护作用。电化学测试表明,该离子液体对这2种钢材的缓蚀作用均属于混合型抑制,但阳极抑制作用表现更强。离子液体对金属的防护作用与其在金属表面的吸附行为有关;[HMIM]BF_4在2种钢材表面的吸附行为符合Langmuir吸附等温线,兼具物理、化学吸附特性,热力学参量表明吸附过程为自发、吸热的熵增过程。相比于双咪唑季铵盐,[HMIM]BF_4离子液体缓蚀剂保护性能更优异,而且对于A3碳钢更为有效。 相似文献
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Xuanliang Zhao Kanglin Zhou Yujia Zhong Peng Liu Zechen Li Jialiang Pan Yu Long Meirong Huang Abdelrahman Brakat Hongwei Zhu 《Nano Research》2021,14(4):1202-1209
Traditional ionic liquids are sensitive to humidity but with long response time and nonlinear response.Pure liquid-state ionic liquids are usually hard for dehydration which have ultralong response time for humidity sensing.The immobilization of ionic liquids provide a possible way for high performance humidity sensing.Hydrophobic materials and structures also promised faster response in humidity sensing,because of easier desorption of water.In this work,we prepared flexible humidity sensitive composites based on hydrophobic ionic liquid and polymer.The combination of hydrophobic ionic liquid with hydrophobic polymer realized linear response,high sensitivity with low hysteresis to humidity.By adjusting the ratio of ionic liquid,not only the impedance but also the hydrophobicity of composite could be modulated,which had a significant influence on the humidity sensing performance.The morphology and microstructure of the material also affected its interaction with water molecules.Due to the diverse processing methods of polymer,highly transparent film fabricated by spinning-coating and nanofibrous membrane fabricated by electrospinning could be prepared and exhibited different response time,which could be used for different application scenarios.Especially,the fibrous membrane made with electrospinning method showed an ultrafast response and could distinguish up to 120 Hz humidity change,due to its fibrous structure with high specific surface area.The humidity sensors with ultrafast,linear response and high sensitivity showed potential applications in human respiratory monitoring and flexible non-contact switch.To better show the multifunction of ionic liquid-polymer composite,as a proof of concept,we fabricated an integrated humidity sensitive color change device by utilizing lower ionic liquid content composite for sensing in the humidity sensing module and higher ionic liquid content composite as the electrolyte in the electrochromic module. 相似文献