Efficient and selective removal of Pb(Ⅱ) from landfill leachate using L-serine-modified polyethylene/polypropylene nonwoven fabric synthesized via radiation grafting technique

In this study,to efficiently remove Pb(Ⅱ) from aqueous environments,a novel L-serine-modified polyethylene/polypropylene nonwoven fabric sorbent(NWF-serine)was fabricated through the radiation grafting of glycidyl methacrylate and subsequent L-serine modification.The effect of the absorbed dose was investigated in the range of 5–50 kGy.NWF-serine was characterized by Fourier transform infrared spectroscopy,thermogravimetric analysis,and scanning electron microscopy.Batch adsorption tests were conducted to investigate the influences of pH,adsorption time,temperature,initial concentration,and sorbent dosage on the Pb(Ⅱ) adsorption performance of NWF-serine.The results indicated that Pb(Ⅱ) adsorption onto NWF-serine was an endothermic process,following the pseudo-second-order kinetic model and Langmuir isotherm model.The saturated adsorption capacity was 198.1 mg/g.NWF-serine exhibited Pb(Ⅱ) removal rates of 99.8% for aqueous solutions with initial concentrations of 100 mg/L and 82.1% for landfill leachate containing competitive metal ions such as Cd,Cu,Ni,Mn,and Zn.Furthermore,NWF-serine maintained 86% of its Pb(Ⅱ) uptake after five use cycles.The coordination of the carboxyl and amino groups with Pb(Ⅱ) was confirmed using X-ray photoelectron spectroscopy and extended X-ray absorption fine structure analysis.

Photo-Grafting Copolymerization of PP Nonwoven Fabric and Its Application for Acidic Dye Adsorption and Filtration

The monomer methacrylamido propyl trimethy ammonium chloride( MAPTAC) was copolymerized onto the fiber surface of polypropylene( PP) nonwoven fabric under ultroviole radiation. The weak acid red GN dye adsorption and adsorptive filtration performance of the resulted PP fabrics were investigated.The results showed that the grafting copolymerization preferred to happen in the inner layer of the fabrics. The water flux of the grafted fabrics decreases with the increase of grafting yield. The collapse of the grafted polymer chains causes the flux increase in acidic condition,or vice versa at alkaline version. The coiling of the polyelectrolyte chains upon the dye adsorption seems to violate the routine assumption of the rigid substrate, and this gets the adsorption energy constant negative. The static adsorption process follows the Lagergren's pseudo-second order kinetic equation. The removals of circa( ca.) 100% of the total permeation volume3 500 mL simulated dye wastewater was reached during permeation.The dye adsorbed fabrics were regenerated by the mixed media of the cationic surfactant / ethanol /water. The grafted fabric assumes stable fabric integrity and stability during permeation,and presents excellent dye adsorption capacity,easy desorption, and repeatable utilization.

Preparation of Immobilized ε-Polylysine PET Nonwoven Fabrics and Antibacterial Activity Evaluation

A novel antibacterial material （L-PET） was prepared by immobilizing ε-polylysine on polyethylene terephthalate （PET） nonwoven fabrics. Surface modifications of the fabric were performed by using a chemical modification procedure where carboxyl groups were prepared on the PET surface, a coupling agent was grafted, and the ε-polylysine was immobilized. Scanning electron microscopy （SEM） was used to analyze the surface morphology of the fabrics, while the toluidine blue method and X-ray photoelectron spectroscopy （XPS） were used to evaluate the grafting densities. The antibacterial activities of the L-PET were investigated by using the shaking-flask method. The electron micrographs showed that the surface of the blank PET and the modified fabrics did not change. The results of XPS analysis confirmed that ε-polylysine was successfully grafted onto the surface of PET. The results of the antibacterial experiments showed that L-PET fabrics had excellent antibacterial activity against Escherichia coli and Staphylococcus aureus, and that L-PET fabrics were stable in storage for at least two years.

Effects of Surfactant Adsorption on Surficial Wettability of Nonwoven Fabrics

All types of surfactants (cationic, anionic and nonionic) reported in this paper could enhance the surficial wettability of polypropylene (PP) and polyethylene terephthalate (PET) nonwoven fabrics. However, the effects of cationic and nonionic surfactants were better. The longer the treatment time of surfactants on the nonwoven fabrics, the better the surficial wettability. The surficial rewetting time would no longer change above a certain treatment time. The rewettability of nonwoven fabrics could be evidently improved just when the concentration of surfactants was just above the CMC, except for sodium dodecylbenzene sulfonate (LAS). The finer the fibers and the looser the structures, the better the surficial rewettability of nonwoven fabrics.

A Study on Modifying the Calculation Model of Valid Opening Size of Heat-bonded Nonwoven Fabrics

It has been found that there are marked errors in the value of valid opening size of heat-bonded nonwoven fabrics between theoretical calculations and engineering measurements. A new modified theoretical model is advanced in this paper. The equivalent diameter of the pore of a fibre web is used to calculate the valid opening size instead of the maximum diameter of inscribed circle used, because the fibres in practical fibre webs are flexible elastomers with definite diameters and the pore of fibre web may produce deformation in screening teat and engineering usage. The results show that the theoretical calculations coincide well with the engineering measurements. This method offers a theoretical basis for computer simulation to the performance of filters of heatbonded nonwoven fabrics.

INFLUENCE OF PROCESSING PARAMETERS AND POWDER BINDER CONTENT ON PROPERTIES OF HIGH LOFT NONWOVEN FABRICS

In this paper, the influence of processing parameters and powder binder content was studied and analysed on the properties of high loft nonwoven fabrics mainly using statistical analysis method. The relationship between the bulkiness and the warmth retention property was also tested. The analytical results reveal that the increase of the powder content, heating temperature and pressure will affect the tensile strength of nonwovens. Moreover, there are interactions between these parameters. The compression properties only change a little for a powder binder content of 15％—20％. However, with the increase of the heating temperature and pressure, the bulkiness and compression rate will reduce significantly. For the bulk density of high loft nonwoven fabrics, there exists a heat transter mechanism of air convection, but the higher the bulkiness of nonwovens, the larger the thickness and the better the warmth retention property of nonwoven fabrics.

A STUDY OF HIGH LOFT NONWOVEN FABRICS USING POWDER BONDING TECHNOLOGY

In this paper, two types of high loft nonwoven fabrics have been constructed in the laboratory apparatus made by ourselves with different binders (polyamide and polyethylene powder) and varying binder contents (10%, 20%, 30% and 40%). The tensile and compression properties of these nonwoven fabrics were tested. It was found that one can reduce powder binder content to increase loft and softness of nonwoven fabrics, but it has to sacrifice its tensile strength. Adhesion force between binder and single fibre was also explored. The experiments showed that the adhesion force at the interface between binder and fibre depends on the fibre variety, the fibre surface morphology, heating temperature and heating time etc..

过滤吸油用PP/PE双组分熔喷非织造布的性能测试研究

以不同质量比的聚丙烯(PP)、聚乙烯(PE)为原料制得PP/PE双组分熔喷非织造布,测试分析了PP/PE双组分熔喷非织造布的性能。结果表明:PP/PE双组分熔喷非织造布的纤网呈现蓬松杂乱的三维结构,纤维直径较细,孔隙率较高;随着PE添加比例增大,PP/PE双组分熔喷非织造布的面密度和厚度增大,拉伸断裂强力、顶破强力略有下降,硬挺度下降,透气性增大;当PP/PE质量比为73时,PP/PE双组分熔喷非织造布的水接触角在129°左右,吸油倍数为18.75,20 s内吸油高度为1.7 mm,空气过滤效率为56.82%,综合性能较好,可应用于过滤、吸油等领域。

基于生成对抗网络的非织造布二维图像重建

非织造布纤维结构的准确表征是其性能分析的重要基础。为了解决基于近似模拟的表征结果中纤维形态、结构与真实样本不一致的问题,提出了一种基于生成对抗网络的非织造布二维图像重建方法。使用全自动光学显微镜对非织造布图像进行抓取,并在此基础上构建纤维生成对抗网络(Fiber generation adversarial network,FGAN)对图像样本进行建模。针对高分辨率图像重建时存在的失真问题,采用多尺度训练策略,同时引入权重多样性损失。采用图像质量评估指标FID作为实验评价指标,分别与DCGAN、WGAN-GP、BEGAN、PROGAN等生成模型进行对比实验。结果表明:FGAN重建的非织造布图像质量更高;消融实验证明,多尺度训练策略与权重多样性损失函数中FID数值分别降低24.52%、20.31%。FGAN模型的提出,使非织造布结构分析摆脱对近似模拟方法的依赖,提供了准确的纤维分布信息,对非织造布的质量评估、性能优化等应用具有重要意义。

光敏抗菌纯棉无纺布的制备及性能研究

以纯棉水刺无纺布为基材,乙酸为溶剂,柠檬酸为交联剂,把壳聚糖接枝在棉无纺布上,再以壳聚糖为载体,固定原卟啉,制备出一种光敏抗菌材料。借助扫描电镜和傅里叶红外光谱仪分析固定前后棉无纺布的形貌及化学结构变化,并探究改性后棉无纺布的力学性能、透气性及抗菌性能。结果表明:棉无纺布表面接枝了壳聚糖与原卟啉,其断裂强力有所减小;在暗室/光照条件下,改性无纺布对金黄色葡萄球菌和大肠杆菌均具有良好的抗菌效果,尤其在光照条件下,原卟啉与壳聚糖的协同抗菌作用,使改性无纺布对大肠杆菌的抗菌率达到99.91%。

医用防护服用聚丙烯SMS抗菌面料制备与表征

为解决医用防护服用聚丙烯SMS非织造布耐久性抗菌问题,利用课题组制备的银氮共掺杂纳米二氧化钛(Ag-N-TiO_(2))光催化抗菌剂,以聚丙烯SMS非织造布为基材,采用浸渍法,通过优化工艺制备出Ag-N-TiO_(2)/聚丙烯SMS非织造布抗菌试样。以大肠杆菌和金黄色葡萄球菌为目标菌种,采用振荡法测试分析了Ag-N-TiO_(2)/聚丙烯SMS非织造布试样的抗菌性能。利用扫描电子显微镜(SEM)表征试样的微观形貌,同时还测试了负载抗菌剂前后试样的主要性能。结果表明:Ag-N-TiO_(2)成功负载到聚丙烯SMS非织造布上,试样对大肠杆菌和金黄色葡萄球菌的抑菌率分别为100%和100%,洗涤20次后其抑菌率分别为100%和96.1%,抗菌耐久性优于AA级,且主要性能良好,均符合医用防护服面料相关标准要求。

基于GA⁃BP的多目标PEDOT∶PSS导电非织造布性能优化

针对聚(3,4-乙撑二氧噻吩)∶聚(苯乙烯磺酸)(PEDOT∶PSS)导电非织造布存在导电性能不稳定和机械性能较差等问题,采用神经网络模型对PEDOT∶PSS导电非织造布进行性能优化。通过收集PEDOT∶PSS导电非织造布的试验数据,作为GA-BP神经网络的输入和输出,并建立针对PEDOT∶PSS导电聚合物配比的优化模型。结果表明:制备PEDOT∶PSS导电非织造布的最佳工艺参数为EDOT与PSS摩尔比例0.3345、过硫酸铵浓度0.0297 mol/L、硫酸铁浓度0.0487 mol/L、盐酸质量分数6.9630%,此时导电非织造布电导率为6.713 S/m,非织造布拉伸断裂强度为4.581 MPa。制备的PEDOT∶PSS导电非织造布经过20 min摩擦后,电导率由6.329 S/m下降到5.348 S/m;经过60 min水洗后电导率由6.536 S/m下降到5.435 S/m,且下降趋势缓慢。认为:所制备的导电非织造布具有良好的稳定性及耐用性。

Relationship between Light Scattering Intensity and Basis Weight of Non-Woven Fabrics

The relationship between light scattering intensity and basis weight of nonwoven fabrics is studied by using the theory of electromagnetic wave propagation and scatter-ing in random media.The theoretical analysis shows that the backscattering intensity of nonwoven fabric is closely related to its basis weight,and 2 series nonwoven samples manufactured by spun-bonded and thermal-bounded processing methods are tested for checking the theoretical expression.The study shows that the scattering intensity increases with increasing basis weight of nonwoven fabrics in exponential equation,and theoretical expression is consistent with the experimental data.

面膜用非织造布的结构与性能

分别以水刺法蚕丝面膜基布和手工法蚕丝面膜基布为研究对象,测试面膜基布的力学性能、透气性能和持液率,探讨面膜结构、性能与应用的关系。试验结果表明:水刺法面膜基布的拉伸性能较好;手工法面膜基布具有优良的透气性能,并且持液率较高。

高熔融指数聚乙烯的性能分析及熔喷探索

对四种高熔融指数聚乙烯(PE)熔喷专用料的性能进行了表征和分析,研究了不同PE的热性能、非等温结晶性能、热稳定性和结晶性能。结果表明:相比D-PE-390、PE-50,PE-120、PE-735具有更高的结晶度、结晶速率及热降解速度;四种PE的热分解温度都在400℃以上,均能满足熔喷的需求。对PE熔喷料进行了熔喷预试验,研究了温度对熔喷纤维微观形貌及直径的影响,研究发现,在210℃下,熔喷纤维分布均匀且平均直径在2μm以下,与市售熔喷聚丙烯纤维相比有一定优势,在熔喷非织造领域具有潜在应用价值。

聚乳酸非织造基材触摸传感电子织物制备及其性能

针对现有薄膜状、硅胶基触摸传感器件抗弯折性差、热湿舒适性不佳等问题,提出了采用柔软亲肤的聚乳酸非织造材料为基材构筑柔性触摸传感电子织物的研究策略,构建聚丙烯酰胺-氯化锂离子水凝胶双向离子导电体系,采用芯吸沉积效应制备石墨烯导电非织造织物,复合形成层叠结构电子织物,研究触摸传感电子织物对触摸动作的识别及不同机械形变对触摸信号的影响规律。结果表明:触摸传感电子织物可定位识别触摸动作;响应时间仅为25 ms,表现出优异的响应速度;在不同速度触摸下,触摸信号波动率仅为5%,表现出优异的稳定性。弯曲循环500次后,触摸传感电子织物的触摸性能仍维持恒定,表现出优异的抗干扰性。此外,触摸传感电子织物具有优异的热湿舒适性,可长期穿戴。基于此,触摸传感电子织物可实现显示界面的控制功能,在可穿戴人机交互领域具有广阔的发展潜力。

RGO粘胶复合织物的电磁屏蔽与电热行为研究

通过涂覆浸渍使还原氧化石墨烯(RGO)与粘胶非织造布复合,实现其功能改性。采用改进的Hummers法制备氧化石墨烯(GO),通过浸渍法制得GO粘胶复合织物,并采用水合肼还原成RGO粘胶复合织物。借助扫描电子显微镜和傅里叶红外光谱表征RGO粘胶复合织物的表观形态与化学结构,重点研究其导电性、电磁屏蔽性和电加热性能。结果表明:随着涂覆次数从5次增加到15次,复合织物的导电性能和电磁屏蔽性能均得到显著提高;在一定厚度范围内,电磁屏蔽效能与试样厚度呈现正线性相关。在0.15 A恒定电流负载下,复合织物在10 s左右就可达到最高温度164.2℃。认为:该制备方法简单有效,制备的复合织物具有优异的导电性能、电磁屏蔽性能和电加热性能。

辐射接枝改性制备功能无纺布用于酸性溶液中Au(Ⅲ)的选择性吸附

为实现酸性溶液中Au(Ⅲ)的选择性回收,本研究以聚乙烯/聚丙烯(PE/PP)皮芯结构无纺布为基材,通过丙烯腈与丙烯酸的辐射接枝以及硫化钠改性制备得到含硫代酰胺基和羧基的双官能化无纺布吸附材料。通过红外光谱、热重分析、扫描电镜、能谱分析、接触角测定、X射线光电子能谱和X射线衍射等测试对改性无纺布的结构与性能进行表征。通过批量吸附试验对改性无纺布的吸附性能进行测定。结果表明:改性无纺布在较宽pH范围(2~7)内具有良好的Au(Ⅲ)吸附能力;在共存金属离子体系中具备良好的Au(Ⅲ)选择性,选择系数介于55.00~2429.17,金回收率可达98.5%;改性无纺布的饱和Au(Ⅲ)吸附容量为133.91 mg/g,吸附行为符合准二级动力学和Langmuir等温吸附模型;Au(Ⅲ)在吸附中可被还原为以晶体形式存在的Au(0);通过对吸附后样品的简单高温处理可去除吸附材料,实现金的回收。

太阳能驱动多级海水淡化器件的设计及其集水率探究

以太阳能驱动为主的界面光蒸汽转化技术是目前广泛使用的一种海水淡化技术,然而,以其为基础制备的海水淡化多级器件依然面临着制备方法复杂、价格昂贵、集水率不高等问题。为解决上述问题,使用廉价易得的紫铜板、碳纤维和粘胶基非织造布等材料,制备了能大幅增加光吸收率的碳纤维阵列光热层,快速供水的粘胶基非织造布水通道和蒸发层,以及快速冷凝水收集的疏水集水层,并以上述3部分为基础构筑太阳能驱动多级海水淡化器件。在确定器件最佳间距为3 mm,级数为十级之后,该器件在一个模拟太阳光照下实现了高达2.05 kg/(m^(2)·h)的集水率。该器件充分利用了潜热实现了高效的水收集,为后续多级界面蒸发器件的设计提供了一种新的思路。

芳纶滤料的粉尘过滤性能

为了给不同高温烟尘过滤工况提供纤维选型参考依据,拓展芳纶在高温烟尘过滤领域的应用,分别测试了芳纶针刺毡与聚酰亚胺针刺毡及玻纤机织布覆膜滤料的过滤性能、耐温性、耐磨性、耐折性、耐酸碱腐蚀性和阻燃性。通过对比分析发现,芳纶针刺毡具有较好的耐温性,在220℃下处理24 h后强力基本不变,并表现出卓越的耐折性和优良的耐酸碱腐蚀性。1 D超细芳纶未覆膜针刺毡表现出较好的过滤性能,但其阻燃性不足以作为阻燃型滤料直接使用,可以通过PTFE乳液浸渍处理得以提升并同时赋予其更好的耐磨性。