不同后整理手段对非织造布针刺过滤材料过滤性能的影响

本文选择了轧光、烧毛、轧光后再烧毛三种整理手段对针刺滤材进行后整理,通过对整理后的试样与未经整理的试样进行过滤性能的对比分析,阐述了不同后整理手段对针刺滤材过滤性能的影响。     

Cooling effect of MWCNT-containing composite coatings on cotton fabrics

Multiwalled carbon nanotubes (MWCNTs) were dispersed in an aqueous solution of epichlohydrin based resin with the aid of a surfactant. The MWCNT-resin solutions were applied onto cotton fabrics to form a thin coating with different MWCNT contents (0, 11.1, 20.0, 33.3, and 50%). The thermal conductivity of the fabrics was measured based on the Newton’s law of cooling. The coating containing 50% MWCNTs showed 151% increase in the thermal conductivity. Infrared thermography was used to characterize the heating/cooling behavior of the fabrics. On contact with a 50°C hot surface, coated fabric that had 50% MWCNTs in the coating layer showed a 3.9°C lower equilibrium surface temperature than the untreated fabric. The cooling rate increased with increasing the MWCNT content within the coating layer. Such an effective cooling performance was attributed to the increased thermal conductivity and surface emissivity of the MWCNT-containing coating layer. The coating showed little influence on water contact angle of the coated fabrics, but slightly decreased the air permeability.     

PSA/BAS水刺滤料过滤性能研究

以玄武岩纤维(BAS)机织布为底层,芳砜纶(PSA)为面层,采用水刺工艺使二者结合制得PSA/BAS水刺滤料.测试了PSA/BAS滤料的过滤性能,并与100％ PSA针刺滤料和BAS机织布进行对比,分析了PSA/BAS水刺滤料用于袋式除尘的技术特点.结果表明:在不同过滤速度下,清洁PSA/BAS水刺滤料对粒径≥6μm颗...     

纳米发泡整理对芳纶过滤材料性能的影响

为提高芳纶过滤材料的过滤效率,以添加不同质量分数纳米陶瓷粉的聚四氟乙烯乳液为涂层剂主要原料,采用发泡剂发泡涂层法对芳纶材料进行表面涂层处理。研究了泡沫涂层对芳纶过滤材料的结构、耐摩擦性、透气性、孔径大小、拒水拒酸碱性以及过滤性能的影响。结果表明:经发泡涂层整理后,芳纶表面形成一层致密薄膜;纳米陶瓷粉质量分数越大,发泡剂发泡效果越好,薄膜愈致密且稳定,同时芳纶过滤材料的耐摩擦性愈好,其孔径大小及透气性略有下降;涂层提高了芳纶的拒酸、拒碱性能,有效减少了滤袋的糊袋,使其清灰性及使用寿命均有所提升;涂层后芳纶的过滤效率显著提高,过滤直径为1 μm以上颗粒物的过滤效率由39.1%提升到60%左右,且过滤直径为10 μm以上颗粒物的过滤效率可达到100%。     

空气过滤材料自洁反吹性能的初步研究

采用工业除尘领域滤袋材料的清灰检测方法对两种拥有不同表面能的空气过滤材料自洁反吹性能进行了检测。结果表明,在初期过滤阶段,相比100%植物纤维制备的滤材,含有60%低表面能纤维的滤材的不粘灰性能明显;在深层过滤阶段,滤材孔径会影响滤材的自洁反吹性能。     

箱体式低压真空等离子体表面处理在非织造过滤产品上的应用

介绍了低压真空等离子体技术及表面处理设备。经等离子体涂层处理的过滤介质可用于不同气体和液体的过滤,如汽车用空气过滤、柴油过滤、血液过滤以及制成具有99%渗透效率的口罩和永久亲水性的电池隔膜等。     

面向21世纪熔喷非织造滤材的性能与设计

本文根据过滤过程模型指出 :要提高过滤效率、降低压损 ,必须提高过滤系数 ,可从滤材形态尺寸和滤材表面性能两方面加以综合考虑。纤维纤度、滤材孔径、滤材表面积、滤材厚度及滤材密度分布 ,滤材表面的化学基团、表面能、空气核、静电及高吸附材料等都是滤材设计的重要因素     

后处理工艺对聚苯硫醚滤料清灰性能的影响

为研究滤料清灰性能的不同影响因素,选取４种聚苯硫醚（PPS）纤维滤料,即未经后处理、烧毛、聚四氟乙烯（PTFE）乳液浸渍和PTFE 微孔膜覆膜处理的滤料为试样,采用滤料动态过滤性能测试仪测试了４种聚苯硫醚纤维滤料的清灰性能,通过扫描电镜观察了过滤前后滤料的表观形貌。测试结果表明：在试验周期内,这４种滤料中,覆膜滤料经粉尘过滤后剩余压差最低,清灰周期最长,清灰性能最为优异;未经处理滤料清灰性能次之;PTFE乳液浸渍滤料由于表面纤维间充满着PTFE 乳液固状物,其清灰性能较差;烧毛处理滤料表面留有面积较大的PPS 纤维烧焦物质,其清灰性能最差。     

拒油拒水型纳米纤维瓦楞纸的制备及性能

静电纺纳米纤维具有比表面积大、纤维直径小、孔隙率高等优点,被广泛应用于空气过滤、能源光电、防水透湿等领域。利用静电纺丝技术制备氟聚氨酯(FPU)/聚氨酯(PU)/氯化锂(LiCl)纳米纤维瓦楞纸复合过滤材料,通过不同测试方法对纳米纤维瓦楞纸复合过滤材料的性能进行表征。结果显示:随着FPU质量分数的增大,纤维直径逐渐增大;当FPU质量分数为12%时,纤维直径较为规整,纤维间无粘连现象,纤维直径分布均匀,平均直径为187 nm,此时纳米纤维膜的水和油接触角分别为131°和133°,有较好的疏水性和疏油性;当纳米纤维膜的面密度为2.632 g/m^2时,纳米纤维瓦楞纸复合过滤材料的过滤效率和过滤阻力分别为93.7%和109 Pa(在气流速度为5.33 cm/s,气溶胶的粒径为0.3μm的条件下测试)。由此可见纳米纤维瓦楞纸复合过滤材料在过滤领域有较好的应用前景。     

活性炭过滤纸板处理聚乙烯醇废水的研究

采用静态吸附法,首先对比了不同种类吸附剂对聚乙烯醇(PVA)废水的处理效果,得出活性炭吸附效果最优;然后进一步从时间、温度、pH、PVA初始浓度探讨了最佳使用条件,得出第1h内,吸附速率最大,第2h便降低90%;温度越高,吸附速率越快,但饱和吸附量会降低,温度宜控制在30~35℃;pH在中性及微碱性条件下较好,宜控制为7~8;PVA初始浓度越高,去除效率越低,因此在低浓度下使用效果更好;最后建立PVA浓度与COD关系方程,进一步使用活性炭抄造过滤纸板,在最佳吸附条件下,采用动态过滤法处理PVA废水,结果显示,在满足外排水质要求下,使用周期为2h。     

Clay minerals affect the stability of surfactant-facilitated carbon nanotube suspensions

Carbon nanotubes (CNTs), because of their wide application, will inevitably enter aquatic systems, but the fate and transport of their suspensions in the environment are largely unknown. Clay minerals are expected to interact with CNT suspensions, affecting their fate and bioavailability. This study investigated the influence of clay minerals (kaolinite and montmorillonite) on the stability of surfactant (SDBS, CTAB, and TX100) facilitated multiwalled CNT (MWCNT) suspensions. Adsorption of the surfactants by MWCNTs and clay minerals was also examined. This is a first study on the interaction between clay minerals and surfactant-CNT suspensions. Sorption of SDBS by clay minerals and MWCNTs followed the order MWCNTs > montmorillonite approximately kaolinite; but sorption of CTAB and TX100 followed the order montmorillonite > MWCNTs > kaolinite. For SDBS suspended MWCNTs, introduction of montmorillonite and kaolinite could not change their stability; for CTAB suspended MWCNTs, both montmorillonite and kaolinite greatly deposited the suspended MWCNTs; for TX100 suspended MWCNTs, montmorillonite could partially deposit the suspended MWCNTs, whereas kaolinite showed minimal effect. Two mechanisms of clay minerals affecting MWCNT suspensions are (1) removal of surfactants by clay minerals from solution and MWCNT surface and (2) bridging between clay mineral and MWCNTs by surfactant.     

Optimization study to improve filtration behaviour of electret filter media

This work reports on a study of air filtration behaviour of electret fibrous filter media prepared from polymeric nonwoven materials using corona-charging process. In this work, a full factorial design of experiments in conjunction with response surface methodology of analysis was used. The single as well as interaction effects of fibre diameter, basis weight, point voltage and grid voltage on filtration efficiency were determined. The filtration efficiency was found to be higher with smaller fibre diameter, higher basis weight, higher point voltage and higher grid voltage. The fibre diameter contributed maximum towards the filtration efficiency, followed by the grid voltage, basis weight, and point voltage. A response surface model was developed to predict the filtration efficiency of the filter media. The model displayed very good correspondence with the experimental results. The experiments performed at the optimum levels of fibre diameter, basis weight, point voltage and grid voltage yielded filtration efficiency very close to the predicted value.     

汽车空气滤清器过滤用材料的结构与性能及其新产品研发

为了研究汽车空气滤清器滤芯用过滤材料在使用前后的结构及性能变化以及杂质颗粒对其性能的影响,从市场上收集了一组相同的使用前后的汽车空气滤清器并且取下过滤材料,分别采用SEM、FT-IR、DTA、TG分析过滤材料在使用前后的内部结构变化。同时,研究过滤材料在使用前后的定量、厚度、透气率、断裂强力及伸长、平均孔径、最大孔径、过滤精度、压降流量的变化情况。研究结果表明,过滤材料在使用前后的结构及性能均有显著变化,并且杂质颗粒的存在会对过滤材料的内部结构、物理性能以及过滤性能产生影响。在此基础之上,开发了三种不同的新过滤材料并且将其性能进行比较。     

定量对双层空气复合滤纸原纸性能的影响

双层复合滤纸的设计对双层复合空气滤纸原纸的性能具有重要的影响。研究了不同总定量及不同定量比的双层复合空气滤纸原纸,探究定量变化对双层复合空气滤纸原纸性能的影响。结果表明,随着总定量的增加,孔径减小,透气度减小,过滤效率增加,容尘量减小;120g/m2时过滤效率为99.68%,容尘量为117g/m2;改变复合滤纸定量比,容尘量先上升后下降,过滤效率基本不变,结合载尘纸样内部结构图,定量比1∶3为最佳值;与单层滤纸相比,复合滤纸过滤效率高于单层滤纸,最大差值为0.1%。     

聚乙烯醇-乙烯共聚物纳米纤维增强聚丙烯微米纤维复合空气过滤材料的结构与性能

为提高常规纤维基空气过滤材料的过滤性能,采用熔融共混相分离法制备得到聚乙烯醇-乙烯共聚物(PVA-co-PE)纳米纤维并制成悬浮乳液,将聚丙烯(PP)针刺基材浸渍到悬浮乳液中进行冷冻干燥处理,得到PVA-co-PE纳米纤维增强PP微米纤维骨架复合空气过滤材料。借助傅里叶变换红外光谱仪、扫描电子显微镜、静电电位计、孔径分析仪及滤料综合测试台对过滤材料的结构及性能进行表征。结果表明:当纳米纤维的面密度为9.34 g/m²时,复合空气过滤材料对尺寸为0.3 μm的NaCl气溶胶粒子的过滤效率为99.936%,阻力压降为81 Pa,品质因数为0.091 9 Pa^-1,且复合过滤材料的拉伸强度及拉伸模量相比PP针刺基材均增加50%。     

Properties of electrospun PVA/nanoclay composites

Laponite^® nanoclay was added to poly(vinyl alcohol) (PVA) solution which was electrospun to make PVA/Laponite^® nanocomposites. After adding Laponite^® nanoclay, fibers were observed to be warped, making their surface rougher. The addition of Laponite^® resulted in less water solubility of electrospun PVA web. PVA/Laponite^® nanocomposite disintegrated after exposure to heat and agitation in water reducing its filtration capability. PVA/Laponite^® nanocomposites showed lower air permeability than electrospun PVA webs probably because of more resistance to air stream caused by rougher and less uniform fiber surface. Tensile and tear strength were weakened by Laponite^® nanoclay due to several reasons: random orientation of nanoclay along fiber axial direction, and fiber discontinuity caused by nanoclay and inhomogeneous distribution of nanoclay.     

聚丙烯腈/BaTiO3复合纳米纤维过滤膜的制备及其性能

为制备高效低阻的纳米纤维过滤膜,将无机驻极体BaTiO₃纳米颗粒加入聚丙烯腈(PAN)溶液中,利用静电纺丝方法制备PAN/BaTiO₃复合纳米纤维过滤膜,对其表面形貌、化学结构、水接触角、力学性能和过滤性能进行分析。结果表明:PAN/BaTiO₃纳米纤维的直径比纯PAN纳米纤维略有降低,且BaTiO₃纳米颗粒均匀地分散在纤维内部;与纯PAN纳米纤维膜相比,PAN/BaTiO₃复合纳米纤维过滤膜的水接触角更大,抗污染能力更强,拉伸强度最高增加了75.5%;当BaTiO₃质量分数为0.75%时,PAN/BaTiO₃复合纳米纤维过滤膜的过滤效率为98.9%,阻力压降为42.7 Pa, 品质因子为0.105 6,其中静电吸附作用占总过滤效果的36.2%,该纤维膜过滤性能最好,且具有一定的循环使用性能。     

针织长毛绒空气过滤材料过滤性能的研究

针对纺织车间粉尘的特点,参照国家标准GB 12218—1989和欧洲标准EN779:2002,建立过滤材料过滤性能测试装置,对针织长毛绒空气过滤材料以及针刺和熔喷非织造空气过滤材料的过滤性能进行了测试与分析。研究表明:针织长毛绒空气过滤材料更适用于纺织车间的除尘和回风过滤,其绒毛平均长度和直径对过滤性能的影响显著,而基布横密对过滤性能的影响不大。     

Impact of porous media grain size on the transport of multi-walled carbon nanotubes

Nanoparticles possess unique physical, electrical, and chemical properties which make them attractive for use in a wide range of consumer products. Through their manufacturing, usage, and eventual disposal, nanoparticles are expected to ultimately be released to the environment after which point they may pose environmental and human health risks. One critical component of understanding and modeling those potential risks is their transport in the subsurface environment. This study investigates the mobility of one important nanoparticle (multi-walled carbon nanotubes or MWCNTs) through porous media, and makes the first measurements on the impact of mean collector grain size (d(50)) on MWCNT retention. Results from one-dimensional column experiments conducted under various physical and chemical conditions coupled with results of numerical modeling assessed the suitability of traditional transport models to predict MWCNT mobility. Findings suggest that a dual deposition model coupled with site blocking greatly improves model fits compared to traditional colloid filtration theory. Of particular note is that the MWCNTs traveled through porous media ranging in size from fine sand to silt resulting in normalized concentrations of MWCNTs in the effluent in excess of 60% of the influent concentration.     

Sorption of peat humic acids to multi-walled carbon nanotubes

Sorption of humic acids (HAs) from a peat soil by multiwalled carbon nanotubes (MWCNTs) was examined in this work. Sorption rate of HAs to MWCNTs was dominantly controlled by their diffusion from liquid-MWCNT boundary to MWCNT surfaces. Size exclusion chromatography analysis did not detect preferential sorption of HA fractions to MWCNTs at equilibrium, whereas the components with lower molecular weight in some HA fractions (e.g., HA1) would more preferentially be sorbed to MWCNTs at the initial sorption stage. Equilibrium sorption intensity of HAs by MWCNTs was dependent on their surface area and a sum of meso- and macropore volume. The surface area and sum of meso- and macroporosity-normalized sorption coefficient (K(d)) values of a given HA by MWCNTs increased with increasing outer diameter of MWCNTs, because MWCNTs with larger outer diameter were more strongly dispersed by HAs thereby making more sorption sites exposed for HA sorption. Van der Waals interaction between the alkyl components rather than the aromatic ones of HAs with MWCNTs was likely the key driving force for their sorption. This study highlights the sorption rate-controlling step of HAs from a same source to MWCNTs and the major factors affecting their sorption intensity at equilibrium.