Separators are considered a key component in lithium-ion batteries (LIBs); however, currently commercial polyolefin separators fall short in meeting the demands of high-performance LIBs due to their low porosity and other issues. In this paper, a novel coaxial electrospray/electrospinning device consisting of an outer nozzle and an inner nozzle is presented, which can simultaneously prepare composites containing nanofibers and nanoparticles. With this device, a new type of LIB separator was successfully fabricated by simultaneously spinning fibers of PVDF and spraying particles of KH570/SiO2 in situ onto an ultra-high molecular weight polyethylene (UHMWPE) separator. The average diameter of the fibers prepared from the inner nozzle is 0.46 mu m, and the average diameter of the particles prepared from the outer nozzle is 70.81 nm. According to the analytical results, the porosity of the separator increases from 37.85% to 81.33%, and the longitudinal shrinkage decreases from 7.28% to 2.63% compared to the unmodified separator. Additionally, the initial charge/discharge specific capacity of the experimental separator increases from 107.8 to 152.0 mAhg-1. Excellent cycling stability of the separators is also exhibited after 50 charging and discharging cycles.

Herein, a novel technology named coaxial electro-spraying/electrospinning was successfully introduced, which can simultaneously prepare nanofibers and nanoparticles. First, the device contains an outer nozzle and an inner nozzle, which combine electrospinning with electro-spraying technology. Then, the polyamide 6 (PA6) was spun to prepare the nanofibers from the inner nozzle, and the silver nanoparticles (Ag NPs) into the PA6 solution were sprayed to prepare the nanoparticles from the outer nozzle. PA6 nanofibers (NFs)/Ag nanoparticles (NPs) antibacterial composite membranes for the filtration of fine particulate pollutants were successfully prepared using coaxial electro-spraying/electrospinning. The microstructure, physical properties, and antibacterial properties of the composite membrane were investigated. The results show that Ag NPs are successfully loaded in situ onto PA6 NFs of approximately 100 nm to form a three-dimensional (3D) structure. The filtration efficiency of the 3D structured filtration membrane reaches 90.98%, compared to only 12.78% for the melt-blown cloth mask filter material when tested with polystyrene microspheres (PS) of 200 nm. The contact angle of the composite membrane decreased from 145.47 degrees to 44.11 degrees, indicating a significant improvement in the hydrophilicity of the membrane. Furthermore, depositing Ag on the surface fibers resulted in an impressive antibacterial rate of 99.75% against Penicillium.

目前,经驻极生产的熔喷布对空气中病毒等微小颗粒的过滤主要依靠其静电吸附机理,但由于熔喷布表面电荷难以持久保持,不能长期保持高效过滤,因而不能保证医护人员不被新型冠状病毒(COVID-19)感染,所以需要提升熔喷布在失电荷时的机械过滤效率.文中利用静电纺丝技术在熔喷布上电纺尼龙6(PA6)纳米纤维,通过热压法制成一种以熔喷布为表层,PA6纳米纤维为中间层的夹心材料;对该夹心材料的表面形貌、热学性能、力学性能进行表征并测试其过滤性能.实验结果表明,夹心材料表面完整度高,纳米纤维直径可达67 nm左右;在没有驻极工艺处理的情况下,该夹心材料对粒径为0.2 μm的颗粒过滤效率达到95％以上,而对照试验的无纺布相应的过滤效率为0;该夹心材料过滤阻力在284 Pa左右,适合作为个体防护使用.

通过计算机模拟建立了一种确定导电填料/高分子复合材料理论渗流阈值的方法.首先,通过以一定比例混合而构成的二相石墨烯/聚氨酯复合材料建模;其次,利用有效介质理论进行计算机模拟计算,得出石墨烯/聚氨酯二相复合电热材料理论渗流阈值.模拟结果表明石墨烯/聚氨酯复合材料中,当石墨烯添加量为3.4 wt％时,该复合电热材料达到了理论渗流阈值.实验以上述模拟结果为基础,采用溶液共混法成功制备出了石墨烯/聚氨酯复合水溶液;实验结果表明,该石墨烯浆料中石墨烯添加量在3.7 wt％时,电热复合材料达到渗流阈值,表明该理论模拟结果与实际实验结果相吻合.使用实验制备的石墨烯/聚氨酯浆料涂覆而成的电热网状材料,在24 V时温度可达50℃.

高性能金属-有机骨架(MOFs)复合材料是目前研究热点.文中首次采用熔体静电纺丝法制备了低密度聚乙烯(LDPE)纤维作为沉积MOFs晶体的衬底,并采用溶剂热合成法原位制备了负载锆基金属-有机骨架材料(UiO-66)的LDPE纤维复合材料.通过扫描电子显微镜(SEM)、X射线衍射(XRD)、傅里叶变换红外光谱分析(FT-IR)和热重分析(TG),对UiO-66@PE纤维复合材料的表面形貌和结构进行了表征.结果表明,UiO-66@PE复合纤维材料最佳制备温度是100℃,它是由UiO-66包裹的纤维态复合材料,且晶体较均匀负载于LDPE纤维表面,UiO-66晶体直径为190～900 nm;FT-IR分析表明UiO-66晶体与LDPE纤维之间没有化学作用;TG分析结果表明,相比基材LDPE,UiO-66@PE复合材料的热分解温度有所提高,能够达到425℃.

In this paper, an ultra high molecular weight polyethylene (UHMWPE) lithium ion battery composite separator was successfully prepared via the electrospraying technique. First, the optimal electrospraying parameters of Polyvinylidene fluoride (PVDF), mass fraction of PVDF 3wt% and electrospraying voltage 21kV, were successfully determined by adjusting the effect of voltage and concentration of PVDF solution. Then the composite separator was prepared by electrospraying PVDF particles on the UHMWPE film. Finally the porosity rate, thermal stability and charge and discharge properties of the separator were analyzed. The analytical results show that the porosity rate of the composite separator is increased from 46.5% to 73.1%, and the heat shrinkage of the separator in the longitudinal is reduced from 2.6% to 1.3%. The first specific discharge capacity of the composite separator increases by 5.8%, and the separator has a good cycle stability after 50 cycles.

以甲醛、甲苯为代表的挥发性有机物(VOCs)严重威胁着人们的身体健康.活性炭具有发达的孔洞结构、高比表面积、物理化学性能稳定等优点,在空气净化方面得到广泛应用.然而,普通活性炭材料的环境治理效率以及性能已经不能满足需求,需要对其进行改性.近年来,研究人员通过选择不同的有机原料(坚果果壳、树叶、秸秆、木材等)、不同的活化剂(磷酸、焦磷酸、氯化锌等)以及不同的加热温度和升温速度,制备出性能不一的改性活性炭材料;对活性炭改性可以进一步增大其接触面积、增强多孔性,因而增强其对香烟烟雾、甲醛等有害气体的吸附能力.综述了改性活性炭材料的制备方法、结构性能以及在空气净化领域应用的新进展,并在此基础上分析了不同材料面临的问题及其应用前景.

以水性聚氨酯为基体,碳纳米管(CNT)为导电填料,制备了碳纳米管电热浆料,并使用纳米碳黑(CB)对其改性,研究了CB的添加量对浆料电热-力学性能的影响.实验结果表明,随着CNT含量的升高,未经CB改性的电热涂膜拉伸强度和断裂伸长率增大,电阻率下降;但当CNT含量达到19％时,在220 V电压下涂膜未出现表观发热现象.制备CNT含量为10％的电热浆料并使用CB改性后,其电热性能得到了很大的提高.对改性后的电热涂膜进行测试,SEM图像显示CB与CNT分布均匀并且CB包覆了CNT;力学性能测试显示,随着CB含量升高,电热涂膜的拉伸强度增大,断裂伸长率减小;电热性能测试显示CB含量为5％时,涂膜出现表观发热现象,当CB含量为7％时,220 V电压下涂膜发热温度达87.8℃.

针对SiO2在有机溶剂中易团聚、静电喷涂过程中易堵塞喷头的缺点,通过使用 γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)与SiO2络合进行接枝改性,对上述改性后的SiO2溶液进行静电喷涂成功得到纳米级别的SiO2颗粒,用上述方法将纳米SiO2静电喷涂到超高分子量聚乙烯(UHWMPE)隔膜上成功制备了锂电池复合隔膜.测试结果表明,复合隔膜的收缩率由7.28％减小到1.32％,孔隙率由37.85％增加到61.15％,其首次充放电比容量从107.9 mAh/g提升至130.6 mAh/g,增加了21％,经过50次循环测试,放电比容量能保持在91.48％.

采用物理混合的方法,以水性聚氨酯(PU)为基体,制备了环保型炭黑基电热碳浆.对发黑基电热碳浆的表面形貌、力学性能、电阻率及电热性能进行了测试,结果表明,当发黑(CB)含量为13％ ～15％时,碳浆膜片具有良好的表面形貌和力学性能,电阻率为28.8～33 Ω·cm,220 V条件下电热温度为70～81℃.在上述材料中加入石墨烯(GO)并对其电热性能进行测试,结果表明,GO的加入能明显改善其电热性能,当导电填料含量为15％且m(GO):m(CB)=12:3时,碳浆膜片在100 V条件下电热温度为50.7℃.

In recent years,because of the requirement of energy conservation and environmental protection,the way of electric heating is widely promoted.The research and application of electrothermal materials are widely regarded.Non-metallic carbon-based electrothermal materials is a new type of energy-efficient electrothermal materials of heating.This paper summarizes the influence factors to electric heating performance and related applications of the carbon black-based electrothermal materials,carbon fiber-based electrothermal materials and carbon crystal electrothermal materials.

A novel composite air purification material with high filtering efficiency,low resistance and anti-static adsorp-tion properties is prepared.The intermediate layer of the material is submicro-fiber membrane,and the upper and lower lay-ers are high temperature resistant glass fiber materials and pre-filtration layer industrial fiber respectively.The resistivity and filtration efficiency of this composite material is analyzed.The results show that the filtration efficiency for particles of 2μm can reach 99.93%,while the pressure is only 490 Pa.A certain proportion of carbon black particles is added in the sandwich layer fibers to improve the electrostatic property of the material.The resistivity of this sandwich purification material significantly reduces from 5.8×1010Ω·m to 6.0×109Ω·m after the addition of 5%nano-carbon black particles in the inner sub-micro-fiber membrane,and this is the reason that the electrostatic property of the sandwich material has been improved.

通过静电喷涂技术成功制备出一种超高分子量聚乙烯(UHMWPE)锂电池复合隔膜.首先研究了纳米二氧化硅(SiQ)在聚偏氟乙烯(PVDF)溶液中的添加量对PVDF/SiO2共混溶液静电喷涂的影响,确定最佳喷涂条件.然后在UHMWPE膈膜上静电喷涂PVDF/SiO2微球,制备出pVDF/SiO2/UHMWPE复合隔膜.最后,对该复合隔膜的孔隙率、热稳定性、充放电性能进行测试.结果表明,该隔膜的孔隙率从46.5％提高到63.1％;纵向热收缩率从2.6％降低到1.3％;在0.2C充放电倍率下,首次放电比容量比相应的UHMWPE隔膜提高了32.5％,经过50次循环,放电比容量稳定,保持在155.7 mAh/g左右.

通过静电喷涂技术成功制备出一种超高分子量聚乙烯(UHMWPE)锂电池复合隔膜.首先通过研究溶液浓度及电压等因素对聚偏氟乙烯(PVDF)溶液静电喷涂的影响,确定最佳喷涂条件为PVDF质量分数3％,喷涂电压21 kV.然后通过在超高分子量聚乙烯隔膜上静电喷涂PVDF颗粒,制备出复合隔膜.最后,对该复合隔膜的孔隙率、热稳定性、充放电性能测试.结果表明,该隔膜的孔隙率从46.5％提高到73.1％;纵向热收缩率从2.6％降低到1.3％;首次放电容量比相应的超高分子量聚乙烯隔膜提高了4.2％,经过50次循环,稳定性良好,可作为锂离子电池隔膜使用.

通过研究溶液浓度及电压等因素对聚偏氟乙烯(PVDF)溶液静电纺丝的影响,确定最佳纺丝条件制备出聚偏氟乙烯纳米纤维.并与超高分子量聚乙烯(UHMWPE)隔膜复合,成功制备出PVDF纳米纤维基超高分子量聚乙烯锂电池隔膜.对该锂电池隔膜的性能测试结果表明,该隔膜的孔隙率为55％,隔膜在横纵向的热收缩率均在1％以内,放电容量比同等测试条件下的超高分子量聚乙烯隔膜提高了4.8％,并且循环稳定性良好,可作为锂电池隔膜使用.

隔膜是锂离子电池的重要组成部分,其主要作用是提供短路保护和避免正负极直接接触,性能优异的隔膜对提高锂电池的综合性能具有重要的作用.超高分子量聚乙烯锂离子电池隔膜具有在高温下能保持尺寸稳定性,抗外力穿刺的能力强等优点,近年来成为新型电源技术研究的热点.研究了超高分子量聚乙烯通过熔融挤出拉伸法和热致相分离法在不同工艺流程下制备锂离子电池隔膜.超高分子量聚乙烯锂离子电池隔膜存在孔隙率低、亲水性差等问题,直接影响到锂电池的充放电容量和循环性.针对上述不足,对近年来改性的方法进行了概括,特别阐述了静电纺丝的改性进展,并对超高分子量聚乙烯锂离子电池隔膜的发展趋势进行了展望.

Due to the absence of the functional group in the poly (p-xylylene) (PPX) based tube, there is limitation of its application such as a catalyst supporter. In this paper a functional tube with a modification of the PPX tube by coating with polyacrylonitrile (PAN) was successfully prepared and its dielectric constant was measured. The results show that the PAN coated PPX tube has an obvious dielectric relaxations, which has no great different with that of a pure PAN film.

mLLDPE non-woven fibers were successfully prepared via melt electrospinning. However, the fibers are thick, and the pores size of membrane made from mLLDPE non-woven fibers is large, so mLLDPE non-woven fibers cannot be directly used as lithium battery separator. Electrospun PVDF nanofibers and the melt-electrospun mLLDPE fibers were combined to form a new compounding membrane, which was successfully applied as lithium battery separator. The porosity rate, thermal stability and charge and discharge properties were characterized. The results show that the porosity rate of the composite separator is 54%~62% and the first specific discharge capacity is 70 mA��h/g with a good cyclic performance. The performance of this compounding membrane is superior to the commercial lithium separator under the same test condition.

Anti-fogging agents are widely applied in industries,agricultural productions,aerospace,civil security and so on.The anti-fogging agent of transparent plastic has currently been the hot spot on the research.In this paper,the recent developments in these areas,such as preparation,anti-fogging mechanism,applied methods and types of anti-fogging agents including poly glycerin fatty acid ester plastic anti-fogging agents,organic-inorganic hybrid anti-fogging agents,new nano anti-fogging agents,were reviewed.A complex anti-fogging agent developed by laboratory of environment materials research center of Beijing Institute of Petrochemical Technology was introduced and looked to the future of it's application.

利用氯化锂/N,N-二甲基乙酰胺(LiCl/DMAc)溶剂体系先后溶解竹纤维素和聚丙烯腈(PAN),配成纺丝液,采用静电纺丝技术成功制备出直径为130 nm～450 nm的竹纤维素/PAN超细纤维.通过研究竹纤维素/PAN超细纤维平均直径与纺丝参数关系发现,该超细纤维的平均直径随着竹纤维素浓度的增大而增大,随纺丝电压的增大而减小,随纺丝距离的增大而减小,且最佳纺丝参数是竹纤维素质量分数为0.8％,纺丝电压为16 kV,接收距离为14 cm.采用该复合纤维制成夹心净化材料并做过滤测试发现,其过滤效率随着夹心层中超细纤维的膜密度和浊液的起始浊度值增加而增大,最大过滤效率可达99.5％.