纤维素多孔三维材料的制备及其应用研究

发布时间：2018-10-14 20:20

【摘要】：多孔材料由于渗透性好、相对密度低、吸附性好、高比表面积和重量轻等优点,逐渐被人们所熟知,并在各个研究领域有了快速的进展。本文是以自然界中分布极广、储量极大的天然高分子材料纤维素为原料开展研究,通过不良溶剂诱导相分离法直接制备纤维素多孔三维材料。相较于当前研究中纤维素多孔三维材料存在的制备工艺复杂、孔径控制困难和需要致孔剂等缺点,本文采用的制备工艺简单,所得纤维素多孔三维材料具有分级孔径结构和孔隙分布均匀等优点。本文主要研究内容包括以下四个方面:(1)采用LiCl/DMAc体系溶解纤维素后,以乙酸乙酯为不良溶剂,通过不良溶剂诱导相分离法制备了纤维素多孔三维材料。通过FE-SEM、TGA、XRD和BET等对纤维素多孔三维材料进行了表征。结果表明,纤维素多孔三维材料具有大孔-介孔多孔径结构、低密度、比表面积大等优点。(2)以纤维素和二氧化钛粉末为原料,采用不良溶剂诱导相分离法直接制备了二氧化钛/纤维素多孔三维复合材料。通过FE-SEM、XRD和FTIR等对二氧化钛/纤维素多孔三维复合材料进行了表征,发现二氧化钛成功附着在纤维素多孔三维材料中且分布均匀。(3)将纤维素多孔三维材料在氮气保护下进行高温碳化后得到碳多孔三维材料。实验发现,碳多孔三维材料比表面积高达605 m~2/g,内部具有大孔-介孔-微孔三级孔径结构。碳多孔三维材料还具有抗燃烧性,在高温吸附领域具有应用潜力。(4)对二氧化钛/纤维素多孔三维复合材料在纺织染料污水处理中的应用进行了初步探究。在紫外光下进行光催化分解实验,考察了不同二氧化钛含量的二氧化钛/纤维素多孔三维复合材料对于染料亚甲基蓝的光催化性能。结果表明不同二氧化钛含量的二氧化钛/纤维素多孔三维复合材料的光催化效率均高于纯二氧化钛粉末。同时,二氧化钛/纤维素多孔三维复合材料还具备优异的可重复利用性,在重复实验9次时仍具有99.34%的光催化染料分解率。证明了纤维素多孔三维材料作为光催化剂载体的可行性,对于便携式光催化材料在实际中的应用具有重要意义。
[Abstract]:Porous materials have been widely known because of their good permeability, low relative density, good adsorption, high specific surface area and light weight, and have made rapid progress in various research fields. In this paper, cellulosic porous three-dimensional materials were directly prepared by using cellulose, a natural macromolecule material, which is widely distributed in nature and has a large amount of reserves, through the method of bad solvent induced phase separation. Compared with the current research on cellulose porous three-dimensional materials, the preparation process is complex, pore size control is difficult, and porous agent is needed, the preparation process of this paper is simple. The cellulosic porous three-dimensional materials have the advantages of graded pore size structure and uniform pore distribution. The main contents of this paper are as follows: (1) after dissolving cellulose in LiCl/DMAc system, cellulose porous three-dimensional material was prepared by the method of bad solvent induced phase separation with ethyl acetate as bad solvent. Cellulose porous three-dimensional materials were characterized by FE-SEM,TGA,XRD and BET. The results show that cellulose porous three-dimensional materials have the advantages of macroporous mesoporous multi-pore structure, low density and large specific surface area. (2) Cellulose and titanium dioxide powder are used as raw materials. Titanium dioxide / cellulose porous three-dimensional composites were directly prepared by bad solvent induced phase separation. TIO _ 2 / cellulose porous three-dimensional composites were characterized by FE-SEM,XRD and FTIR. It was found that titanium dioxide was successfully adhered to cellulose porous three-dimensional materials and distributed evenly. (3) carbon porous three-dimensional materials were obtained by carbonizing cellulose porous three-dimensional materials under the protection of nitrogen gas at high temperature. It is found that the specific surface area of carbon porous three-dimensional materials is as high as 605mg / g, and the internal structure is macroporous, mesoporous and microporous with tertiary pore size. Carbon porous three-dimensional materials also have anti-combustibility and have potential applications in the field of high temperature adsorption. (4) the application of titanium dioxide / cellulose porous three-dimensional composites in textile dye wastewater treatment was preliminarily explored. The photocatalytic properties of TIO _ 2 / cellulose porous three-dimensional composites with different TIO _ 2 contents for dye methylene blue were investigated by photocatalytic decomposition experiments under ultraviolet light. The results show that the photocatalytic efficiency of TIO _ 2 / cellulose porous three-dimensional composites with different TIO _ 2 content is higher than that of pure TIO _ 2 powder. At the same time, the TIO _ 2 / cellulose porous three-dimensional composite also has excellent reusability, and still has 99.34% photocatalytic dye decomposition rate when repeated for 9 times. The feasibility of cellulosic porous three-dimensional material as photocatalyst carrier is proved, which is of great significance for the practical application of portable photocatalytic materials.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ352.79;TB383.4

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