Taha AmanyE, Mowafi Salwa, Hamouda Asmaa S
Environmental Sciences And Industrial Development Department, Faculty of Postgraduate Studies for Advanced Sciences (PSAS), Beni-Suef University, Egypt.
Proteinic and Man-made Fibers Department, Textile Research and Technology Institute, National Research Centre, 12622-Dokki, Giza, Egypt.
Heliyon. 2024 May 27;10(11):e31318. doi: 10.1016/j.heliyon.2024.e31318. eCollection 2024 Jun 15.
This work aims at the preparation and characterization of dual-layer (DL) nano-fibrous mat (NFM) of hydrophobic and mechanical stable polyacrylonitrile (PAN) nano-fibers (NFs), as a supporter, and polyamide 6 (PA)/chitosan (Ch) NFs as a top hydrophilic coating layer. PAN and PA fibers, as residual wastes from textile processes, were collected and dissolved in their proper solvents. PAN was electro-spuned under certain conditions of electro-spinning (voltage, flow rate, and distance between spinneret and collector) to obtain PAN-NFM. Different ratios of PA/Ch composite were prepared and then electro-spun above the PAN-NFM that was previously prepared to obtain hydrophobic/hydrophilic functional dual-layer nano-fibrous membrane (DLNFM). The efficiency of the prepared DLNFM for capturing dye residues and heavy metals from wastewater was investigated. The viscosities of the prepared composite solutions were measured. The prepared dual-layer nano-fiber membranes (DLNFMs) were chemically and physically characterized by Fourier transform infrared spectroscopy, scanning electron microscope, X-ray diffraction, and thermogravimetric analyzer. The potential of the prepared mats for the adsorption of some heavy metal ions, i.e., Cu, Cr, and Pb cations in addition to dyes from wastewater was evaluated. The effect of using different concentrations of PA/Ch composite as well as the thickness of the obtained DLNFM on the filtration efficiency was studied. The results of this study show the success of functional DLNFM in dye and heavy metal removal. The maximum removal efficiency of acid dyes was reached to 73.4 % and of reactive dye was approximately 61 % for PAN/PA-1.25%Ch DLNFM after 3 days at room temperature. The removal efficiency percent of heavy metal ions reached to 54 % by DLNFM. Additionally, the results showed that 0.08 mm is the ideal thickness for maximum absorption capacity. This value is correlated with the membrane's highest Ch percentage, which is (PAN/PA-1.25%Ch). Furthermore, the results demonstrate that the presence of the Ch polymer strengthened the produced bi-layered membrane to achieve the highest thermal stability when compared to the other nano-fibrous membranes (NFMs), with the breakdown temperature of the Ch functionalized dual-layer membranes (DLMs) reaching approximately 617 °C and a maximum weight loss of 60 %.
这项工作旨在制备并表征由疏水且机械稳定的聚丙烯腈（PAN）纳米纤维（NFs）作为支撑层、聚酰胺6（PA）/壳聚糖（Ch）纳米纤维作为顶部亲水性涂层的双层（DL）纳米纤维毡（NFM）。收集纺织过程中产生的残余废料PAN和PA纤维，并将它们溶解在合适的溶剂中。在特定的静电纺丝条件（电压、流速以及喷丝头与收集器之间的距离）下对PAN进行静电纺丝，以获得PAN-NFM。制备不同比例的PA/Ch复合材料，然后在先前制备的PAN-NFM上方进行静电纺丝，从而获得疏水/亲水功能双层纳米纤维膜（DLNFM）。研究了所制备的DLNFM从废水中捕获染料残留和重金属的效率。测量了所制备的复合溶液的粘度。通过傅里叶变换红外光谱、扫描电子显微镜、X射线衍射和热重分析仪对所制备的双层纳米纤维膜（DLNFM）进行化学和物理表征。评估了所制备的毡对一些重金属离子（即Cu、Cr和Pb阳离子）以及废水中染料的吸附潜力。研究了使用不同浓度的PA/Ch复合材料以及所获得的DLNFM的厚度对过滤效率的影响。本研究结果表明功能性DLNFM在去除染料和重金属方面取得了成功。对于PAN/PA-1.25%Ch DLNFM，在室温下放置3天后，酸性染料的最大去除效率达到73.4%，活性染料的去除效率约为61%。DLNFM对重金属离子的去除效率达到54%。此外，结果表明0.08毫米是实现最大吸附容量的理想厚度。该值与膜中最高的Ch百分比相关，即（PAN/PA-1.25%Ch）。此外，结果表明，与其他纳米纤维膜（NFM）相比，Ch聚合物的存在增强了所制备的双层膜，使其具有最高的热稳定性，Ch功能化双层膜（DLM）的分解温度达到约617℃，最大失重为60%。
