有机高分子纳米纤维膜的制备及吸附性能研究

发布时间：2018-05-21 09:40

本文选题：静电纺丝 + β　；参考：《吉林大学》2017年硕士论文

【摘要】：随着现代化工业的快速发展,含有重金属离子和有机染料等有害污染物的工业废水排入江河等自然水体中,经食物链富集作用间接被人类吸收,进而产生许多严重的疾病,成为亟待解决的重大社会问题。因此,建立工业废水处理技术,实现工业废水的达标排放意义重大。传统的处理方法主要包括化学药剂处理、树脂及活性炭吸附、反渗透等方法存在成本高、难以达到排放要求或引起二次污染等问题。静电纺纳米纤维具有直径细小、比表面积大、吸附速度快、再生时间短、易于洗脱及能实现连续制备等优点,在工业废水治理中展现了良好的应用前景,是近些年的研究热点。本论文从吸附性能良好的β-环糊精和聚乙烯亚胺出发,在模板剂参与下,采用静电纺丝技术制备了两种交联型纳米纤维,并研究了其对金属离子和有机染料的吸附性能。主要研究内容包括以下三个方面:针对环糊精在PVA/H2O溶液中溶解度较低,难以获得高环糊精含量的、交联型PVA/β CD纳米纤维的问题。以六氟异丙醇(HFIP)和H2O为混合溶剂,将PVA/β CD纳米纤维中的环糊精含量提到70%,并经戊二醛交联处理后,制备了不溶于水的PVA/GA/β CD纳米纤维。通过红外光谱和扫描电子显微镜研究了交联前后纳米纤维组成和形貌的变化情况;考察了PVA/GA/β CD纳米纤维对7种水溶性染料的吸附性能。研究发现,纳米纤维对孔雀石绿、甲基紫和刚果红的吸附效果较好,最大吸附量分别为124.71、121.14和127.39 mg/g。循环4次后,染料去除率仍为80%。以聚丙烯腈(PAN)为载体,聚乙烯亚胺(PEI)为吸附剂,环氧氯丙烷(EPI)为交联剂,从PEI/EPI/PAN混合溶液出发,经静电纺丝技术和热交联方法处理得到了不溶于水的交联型PEI/EPI/PAN纳米纤维。通过红外光谱和扫描电子显微镜研究了交联前后纳米纤维组成和形貌的变化情况;考察了纤维膜对水中铜离子、铅离子、铬酸根离子和甲基橙等的吸附情况,结果表明,交联型PEI/EPI/PAN纳米纤维对铜离子,铅离子,甲基橙和铬酸根离子的最大吸附量分别达到349.65 mg/g,289.85mg/g,636.94 mg/g和211.86 mg/g。经过4或5次循环,对铜铅的吸附率能达90%左右;对甲基橙的吸附率达到75%,对铬酸根的吸附率也可以达到60%。从聚丙烯腈/聚乙烯亚胺混合溶液出发,在制备PEI/PAN电纺纤维基础上,经环氧氯丙烷/丙酮交联处理,得到了交联型PEI/PAN/EPI纳米纤维,研究了纤维膜在交联前后的纤维组成和形貌变化情况,考察了纤维膜对有害污染物的吸附情况,发现其对甲基橙,铬酸根和铜铅离子的吸附情况,发现其相应的最大吸附量分别595.24 mg/g,194.55 mg/g,314.46 mg/g和277.77 mg/g。
[Abstract]:With the rapid development of modern industry, industrial wastewater containing heavy metal ions and organic dyes and other harmful pollutants is discharged into rivers and other natural water bodies. It has become a major social problem to be solved urgently. Therefore, it is of great significance to establish industrial wastewater treatment technology and achieve the standard discharge of industrial wastewater. Traditional treatment methods mainly include chemical treatment resin and activated carbon adsorption reverse osmosis and other methods such as high cost it is difficult to meet the emission requirements or cause secondary pollution and other problems. Electrospun nanofibers have the advantages of fine diameter, large specific surface area, fast adsorption rate, short regeneration time, easy to be eluted and can be prepared continuously. They have shown a good application prospect in industrial wastewater treatment, and have been a hot research topic in recent years. In this paper, two kinds of cross-linked nanofibers were prepared by electrostatic spinning with the participation of template, and their adsorption properties for metal ions and organic dyes were studied. The main research contents include the following three aspects: for the low solubility of cyclodextrin in PVA/H2O solution, it is difficult to obtain high cyclodextrin content, cross-linked PVA/ 尾 -CD nanofibers. Using hexafluoroisopropanol (HFIP) and H _ 2O as the mixed solvent, the cyclodextrin content in PVA/ 尾 -CD nanofibers was raised to 70%. After crosslinking with glutaraldehyde, the water-insoluble PVA/GA/ 尾 -cyclodextrin nanofibers were prepared. The changes of the composition and morphology of the nanofibers before and after crosslinking were studied by infrared spectroscopy and scanning electron microscopy, and the adsorption properties of PVA/GA/ 尾 -CD nanofibers to 7 kinds of water-soluble dyes were investigated. The results showed that the adsorption of malachite green, methyl violet and Congo red was better with the maximum adsorption capacity of 124.71 121.14 and 127.39 mg / g, respectively. After 4 cycles, the dye removal rate is still 80%. Using polyacrylonitrile (pan) as carrier, polyethyleneimine (PEI) as adsorbent and epichlorohydrin (EPI) as crosslinking agent, water insoluble crosslinked PEI/EPI/PAN nanofibers were prepared by electrospinning and thermal crosslinking from PEI/EPI/PAN mixed solution. The changes of the composition and morphology of nanofibers before and after crosslinking were studied by infrared spectroscopy and scanning electron microscope, and the adsorption of Cu ~ (2 +), Pb ~ (2 +), Chromate ~ (2 +) and methyl orange on the membrane was investigated. The maximum adsorption capacity of cross-linked PEI/EPI/PAN nanofibers for copper ion, lead ion, methyl orange and chromate ion is 349.65 mg / g, 289.85 mg / g, 636.94 mg/g and 211.86 mg / g, respectively. After 4 or 5 cycles, the adsorption rate of copper and lead can reach 90%, the adsorption rate of methyl orange is 75 and the adsorption rate of chromate can reach 60%. Based on the preparation of polyacrylonitrile / polyethyleneimine solution and the preparation of PEI/PAN electrospun fibers, crosslinked PEI/PAN/EPI nanofibers were obtained by crosslinking with epichlorohydrin / acetone. The changes of fiber composition and morphology before and after crosslinking were studied. The adsorption of harmful pollutants by fiber membrane was investigated. The adsorption of methyl orange, chromate and copper and lead ions was found. It is found that the corresponding maximum adsorption capacity is 595.24 mg / g, 194.55 mg / g, 314.46 mg/g and 277.77 mg / g, respectively.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703;TQ342.86

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