静电纺纳米纤维复合梯度型空气过滤材料的研究进展

概述了静电纺纳米纤维及其复合梯度过滤材料的特性,详述了国内静电纺纳米纤维复合梯度型空气过滤材料的制备、过滤模型理论及数值模拟等研究进展。基于不同纤维层过滤不同粗细颗粒物,每一层纤维网发挥各自独特作用,可采用多种结构和折叠结构复合,增大过滤面积,制备多层梯度的静电纺纳米纤维复合滤材,使滤材具有高效低阻、容尘量大、使用寿命长等特点,是未来空气滤材的重点研发方向;同时应加强过滤模型设计与数值模拟研究,通过滤材的应用数据不断修正模型,促进滤材性能的改进。     

静电纺丝法制备空气过滤膜及应用

详细阐述了静电纺丝技术以及静电纺空气过滤膜材料的性能。提出了静电纺制备空气过滤材料存在的工艺问题及改进方法。综述了静电纺制备纳米纤维过滤材料及其复合改性研究进展。最后总结了静电纺空气过滤材料的应用。     

静电纺丝纳米纤维膜空气过滤研究进展

静电纺丝纳米纤维膜具有高比表面积、孔径小、孔隙率高、纤维均一性好等优点,在空气过滤及个体防护等领域表现出巨大的应用潜力.总结了近年来国内外关于静电纺丝法制备高效低阻和功能化(抗菌、可降解、疏水和耐高温)新型空气过滤材料的最新研究成果,分析和讨论了现有研究中存在的问题,并对未来的发展方向进行了展望.     

静电纺聚偏氟乙烯及其复合纳米纤维膜在过滤领域的研究进展

静电纺丝作为一种可以制备纤维直径几纳米至几微米之间超细纤维技术,是目前获得纳米尺寸纤维最有效的方法之一,聚偏氟乙烯(PVDF)也因其优异的物理和化学性能在众多领域备受青睐。近年来,利用静电纺丝技术制备直径分布、孔径大小以及所需性能等各方面达到指定要求的PVDF及其复合纳米纤维膜成为了国内外学者的研究热点。目前,已成功制备出了多种高性能化和多功能化的PVDF纳米纤维膜,并在医学、电工电气以及过滤等诸多领域有着十分广阔的应用前景。文中简述了静电纺PVDF及其复合纳米纤维膜的原理和影响因素,对电纺PVDF及其复合纳米纤维膜在空气过滤、油水分离以及重金属吸附等过滤领域的应用进行了介绍,指出电纺PVDF及其复合纳米纤维膜可能存在的问题及发展前景。     

纳米纤维复合材料在污水过滤领域的研究进展

纳米纤维在污水过滤领域是最有发展前途的过滤材料。阐述了静电纺纳米纤维过滤材料对液体的过滤机制,总结了有关静电纺纳米纤维过滤材料对重金属离子和有机污染物及细菌的应用研究现状,简单讨论了纳米复合过滤材料当前存在的问题和挑战,并展望了静电纺纳米纤维过滤材料在污水处理领域的应用。     

纳米纤维膜在空气净化中的应用研究进展

面向空气净化的应用需要,开发高效净化材料已成为研究热点之一,其中具有相互连贯孔结构的纳米纤维膜在高效空气净化领域展示出巨大的应用前景。对于纳米纤维膜对空气净化效果的评估指标通常包括过滤效率和过滤阻力。本文介绍了串珠、蛛网和复合等结构纳米纤维膜的研究进展,分析了驻极式纳米纤维膜在高效除尘方面的应用现状,探讨了银纳米颗粒和半导体金属氧化物改性纳米纤维膜在抗菌和除有机易挥发性气体等多功能性空气净化中的应用可行性,指出了高效低阻、功能化是纳米纤维膜用于空气净化领域的研究重点。并提出今后应高度关注多污染物对纳米纤维空气净化膜性能的影响,深入研究具有多功能协同作用的纳米纤维空气净化膜,以期获得更广泛的应用。     

水过滤用膜材料的制备及其性能研究进展

根据过滤分离用水处理膜的制备工艺的不同,重点介绍了三种形式的膜:平板膜、中空纤维膜以及静电纺纤维膜。平板膜因为制备工艺简单、操作便捷,最易于进行功能化改性,因此属于研究最为广泛的一种水处理膜,但是由于受到平板膜内部孔隙率及孔结构的影响,其较小的过滤通量又在一定程度上限制了其应用。中空纤维膜的孔结构特点类似于平板膜,但是其易于集成及器件化的特点,使其成为目前工业用膜的主要形式之一。静电纺纤维膜的产业化应用还处于初级阶段,然而静电纺丝技术是一种制备直径为微米至纳米级超细纤维的重要方法,静电纺纤维膜比表面积大、纤维直径小、空隙率高等优点使其在水过滤、气过滤方面拥有巨大的发展潜力。无论是哪种形式的膜材料,研究者们都致力于对过滤膜在高效化、功能化和环境友好性方面展开深入的研究。     

纤维基耐高温空气过滤材料研究进展

高温含尘废气的排放是造成环境污染的主要原因之一，纤维基空气过滤材料具有比表面积大、结构可控等一系列优点，在空气过滤领域备受关注。但普通纤维基空气过滤材料存在耐高温性能差的问题，为便于相关人员更好了解纤维基耐高温空气过滤材料的研究现状，本文对近年来纤维基耐高温非织造空气过滤材料的研究进展进行了综述。重点介绍了纤维基耐高温非织造空气过滤材料所用原料（有机纤维原料、无机纤维原料等），制备工艺（针刺、水刺、熔喷、静电纺、离心纺和气流纺等）及其功能化改性（脱硫、脱硝、脱VOCs等）应用。对耐高温非织造空气过滤材料制备和应用过程中存在的缺点进行了讨论，指出未来发展应以开发新材料、改进制备工艺和功能化改性为重点方向；以期为耐高温非织造空气过滤材料的研究提供一定参考，拓展纤维基耐高温空气过滤材料应用范围。     

不同相对湿度下亲疏水纳米纤维膜空气过滤性能实验研究

利用静电纺丝法制备了表面静态接触角为23.6°的具有亲水功能的PAN/PVP复合纳米纤维膜、接触角为81.2°的PAN纳米纤维膜、接触角为131.9°的具有疏水功能的PAN/PVDF复合纳米纤维膜。利用自行搭建的空气过滤实验台,在40%、55%、70%三种相对湿度下对三种纳米纤维膜进行空气过滤实验,对纳米纤维膜的过滤效率、阻力损失及品质因子进行分析。结果表明：三种纳米纤维膜的过滤效率随着相对湿度的增大而升高,PAN/PVP膜和PAN膜的阻力损失随着相对湿度的增大而增加,PAN/PVDF的阻力损失随着相对湿度的增大而减小;PAN/PVP膜和PAN膜的品质因子随着相对湿度的增大而减小,PAN/PVDF膜的品质因子随着相对湿度的增大而增大,湿度越大,PAN/PVDF纳米纤维膜的过滤性能越显著。     

静电增强纤维过滤技术的研究进展

综述了静电增强纤维过滤技术的发展历史以及国内外研究进展;介绍了Apitron静电袋式过滤器、TRI棒帷电极电场增强袋滤器、中心电场袋式除尘器、混合式电袋除尘器、静电增强空气过滤器的结构、特点及其应用;指出静电增强纤维过滤技术是一种高效低阻的过滤除尘方式,但在处理高浓度的工业烟尘时,粉尘的积聚使静电作用产生负效应,限制了该技术的发展及应用。建议通过提高静电增强作用,提高过滤材料的静电性能和过滤性能,保持过滤材料高效的驻极状态,应用高效清灰方式,来进一步拓展静电增强纤维过滤技术的应用。     

静电纺丝法制备醋酯纳米纤维的最新研究进展

采用静电纺丝法制备醋酯纳米纤维,既可以保留醋酯纤维的耐化学性和可生物降解性等优点,又具有纳米材料的高比表面积、高孔隙率和量子效应。综述了近几年国内外静电纺丝法制备纳米级醋酯纤维的最新研究进展,系统介绍了几种新型纳米纤维结构的制备方法、原理及影响因素,同时对醋酯纳米纤维在吸附过滤方面的应用研究状况进行了概述,最后对静电纺丝法制备醋酯纤维的发展前景进行了展望。     

基于纤维取向的纳米纤维滤料设计及其性能

通过基于霍夫变换的图像分析法获取静电纺纳米纤维取向分布信息,分析纤维取向对纳米纤维滤料性能的影响,并据此设计制备了中间为杂乱纤维层、两侧为相互垂直的取向纤维层构成的复合纳米纤维膜滤料。采用扫描电镜对纳米纤维膜形貌进行观察并获取SEM图像,进行了透气性、拉伸性能、孔径尺寸和过滤性能测试。结果表明,纳米纤维膜纤维分布方向拉伸断裂强度高,纤维取向各向异性比例理论值和实验值相吻合,纤维取向是影响纳米纤维膜力学各向异性的主要参数;取向纳米纤维膜滤料孔径较大且有许多微粒可逃逸的通道,其过滤效率和过滤阻力均较低,与文献中报道的数值模拟结果相一致;所设计制备的复合纳米纤维膜滤料结合了取向纳米纤维膜滤料力学性能优良和杂乱纳米纤维膜滤料过滤效率高的优点,其纵向和横向断裂强度分别为8.85MPa和8.71MPa,气流流速为25L/min时过滤效率高达99.691%。     

Preparation and Properties of PVDF/Fe3O4 Nanofibers with Magnetic and Electret Effects and their Application in Air Filtration

Electrospun electret filter material is widely studied because of its excellent removal effect on particulate matter from air streams. Here, a kind of high efficiency and low pressure drop nanofiber (NF) membrane with both electret effect and magnetic effect is developed, and compounded it with glass fiber mesh and polyester (polyethylene terephthalate) mesh to prepare a sandwich structure of NF anti‐haze window screen. Under the synergistic effect of magnetic particles, when the density is 2.06 g m^?2, the filtration efficiency of NF anti‐haze window screen can reach 99.95% for the fine particles below 0.3 µm, while the filtration pressure drop is only 58.5 Pa, with good light transmittance and excellent breaking strength (6.32 MPa). Therefore, polyvinylidene fluoride/Fe₃O₄ composite NF membrane has a potential application prospect in the field of air filtration.     

3D modeling of filtration process via polyurethane nanofiber based nonwoven filters prepared by electrospinning process

Full 3D particle filtration modeling at low pressures considering slip/transition/free molecular flow regime, particle–fiber interactions, air/particle slip, sieve and homogenous flow field has been performed for the polyurethane nanofiber filter prepared by electrospinning process and the obtained theoretical predictions for the filtration efficiency have been compared with the corresponding experimental data. Moreover, the effect of air velocity, viscosity, temperature, pressure and particle–fiber friction coefficient on the produced polyurethane nanofiber filter efficiency has been investigated in more details. In order to take all real structure features of the nanofiber filter into account (such as varying fiber diameter, curvature along its length, inhomogeneity and mat defects), a new approach for 3D nanofiber mat model construction from corresponding SEM images has been proposed and utilized.     

Improvement in nanofiber filtration by multiple thin layers of nanofiber mats

Nanofiber filtration is drawing great interest nowadays because of its large surface collection area as well as low air resistance. In this study, electrospun nanofiber mats of different thicknesses were evaluated for their filter quality factors. Shorter-term electrospun fiber mats exhibited a better quality factor than those longer-term electrospun ones. Multiple thin layers of nanofiber mats to improve the filter quality of the nanofiber filters were then evaluated. Filtration test results showed that the filter made up of multiple thin layers of nanofiber mats had a filter quality factor much higher than the single thick layer nanofiber mat. Better thickness uniformity in the multi-layer structure due to stacking compensation and smaller fiber diameters in nanofibers of short-term deposition time are two possible reasons for the improvement of the filter quality.     

Biodegradable Electrospun Poly(lactic acid) Nanofibers for Effective PM 2.5 Removal

In addition to the rapid urbanization and industrialization around the world, air pollution due to particulate matter is a substantial threat to human health. A considerable research effort has been devoted to the development of electrospun polymer nanofibers for air filter applications. Among these new technologies, electrostatic charge‐assisted air filtration is a promising technology for removing small particulate matter (PM). In this investigation, biodegradable electrospun poly(l ‐lactic acid) (PLLA) polymer nanofibers are employed for air filter applications. Electrostatic charges generated from the PLLA nanofiber can significantly enhance air filter applications. Compared with a 3M commercial respirator filter, electrospun PLLA fibrous filters exhibit a high efficiency of 99.3%. Even after 6 h of filtration time, the PLLA filtration membrane still exhibits a 15% improvement in quality factor for PM 2.5 particles than the 3M respirator. This is mainly attributed to the electrostatic force generated from the electrospun PLLA nanofibers, which significantly benefit submicron particle absorption. Due to their biodegradability, ease of fabrication, and relatively high efficiency, electrospun PLLA nanofibers show great promise in applications such as air cleaning systems and personal air purifier applications.     

滑移效应下纤维绕流场及过滤阻力的数值计算与分析

考虑实际纳米/微米纤维表面的流体滑移效应,采用数值方法求解滑移流动机理下纳米/微米纤维绕流场及过滤阻力,分析讨论了Knudsen数Knf和填充率C对纤维近壁面速度分布及纤维过滤阻力的影响规律.结果表明,对纳米/亚微米纤维过滤情形,纤维表面流体的滑移效应导致纤维绕流场与非滑移条件下情形有显著差异,尤其在高填充率下,纤维表...     

Effect of air blowing on the morphology and nanofiber properties of blowing‐assisted electrospun polycarbonates

Polycarbonate (PC) nanofibers are prepared using the air blowing‐assisted electrospinning process. The effects of air blowing pressure and PC solution concentration on the physical properties of fibers and the filtration performance of the nanofiber web are investigated. The air blowing‐assisted electrospinning process produces fewer beads and smaller nanofiber diameters compared with those obtained without air blowing. Uniform PC nanofibers with an average fiber diameter of about 0.170 μm are obtained using an applied voltage of 40 kV, an air blowing pressure of 0.3 MPa, a PC solution concentration of 16%, and a tip‐to‐collection‐screen distance (TCD) of 25 cm. The filtration efficiency improvement of the air blowing‐assisted electrospun web can be attributed to the narrow distribution of fiber diameter and small mean flow pore size of the electrospun web. Performance results show that the air blowing‐assisted electrospinning process can be applied to produce PC nanofiber mats with high‐quality filtration. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011