基于天然纤维素的环境功能材料的制备与性质研究

发布时间：2018-10-30 12:22

【摘要】：随着全球人口的急剧增长和经济的快速发展,资源短缺和环境污染已成为人类当前面临的两大难题,利用可再生资源开发环境友好型的新功能材料在当今严酷的现实条件下具有重要的现实和长远意义。纤维素来源广泛、价格低廉、可塑性强,可用于合成、制备可降解环保材料;利用其复杂的微观网络结构,纤维素还可作为制作新型纳米功能材料的理想模板。基于以上原因,本文以纤维素为基础,开展环境功能材料的制备与研究。(1)以精制棉纤维素为主要原料,利用乙酰化改性制得醋酸纤维素(CA),在CA中混入不同比例的自制醋酸酯淀粉(SA),通过交联剂柠檬酸三丁酯的作用使混合体系发生交叉克莱森酯缩合反应融合成铸膜液,制备得到了生物降解塑料薄膜。通过对FT-TR、XRD、SEM、TGA和力学性能等表征结果和土壤填埋降解实验结果的分析,发现制膜原料各组分融合较好,塑料膜成膜紧密,结构平整、光滑,热稳定性突出,力学性能也基本符合实用需求;降解性能良好,通过改变SA的含量,可实现生物降解膜在自然环境中的可控降解。(2)以脱脂棉和滤纸纤维素为模板和构筑支架,以钛酸四丁酯为钛源,利用表面溶胶-凝胶法在纤维素表面沉积溶胶薄膜,通过分别在氮气氛围和空气氛围中煅烧,制备得到:掺杂和未掺杂铈元素的二氧化钛碳纳米纤维材料及二氧化钛纳米管。利用FT-TR、XRD、SEM、TGA和BET等多种表征手段和亚甲基蓝降解实验考察了不同条件下制得样品的结构特点与光催化性能,发现氮氛围中煅烧的二氧化钛凝胶层转化为锐钛矿晶型,并完全贴合、附着在碳纳米纤维表面,复制了纤维素的微观结构特征,成功实现了催化剂的固定化;催化剂样品具有较大的比表面积和良好的晶相结构,而掺杂的铈元素进一步改善了样品的结晶特性和光催化性能。
[Abstract]:With the rapid growth of global population and rapid economic development, the shortage of resources and environmental pollution have become two major problems facing mankind. The exploitation of environment-friendly new functional materials using renewable resources is of great practical and long-term significance in today's harsh reality. Cellulose has a wide range of sources, low price, strong plasticity, can be used for synthesis, preparation of degradable environmental protection materials, and the use of its complex micro-network structure, cellulose can also be used as an ideal template for the preparation of new nano-functional materials. For the above reasons, the preparation and study of environmental functional materials based on cellulose were carried out in this paper. (1) cellulose acetate (CA), was prepared by acetylation of refined cotton cellulose as main raw material. The biodegradable plastic film was prepared by mixing different proportions of self-made acetate starch (SA), in CA through crosslinking agent tributyl citrate to fuse the mixture system to cast film solution. Through the analysis of FT-TR,XRD,SEM,TGA, mechanical properties and the results of soil landfill degradation experiment, it was found that the components of the film were fused well, the plastic film was closely formed, the structure was smooth, and the thermal stability was prominent. The mechanical properties also basically meet the practical needs; The biodegradable film can be controlled degraded in natural environment by changing the content of SA. (2) the biodegradable membrane was prepared by using cotton and filter paper cellulose as template and scaffold, and tetrabutyl titanate as titanium source. The surface sol-gel method was used to deposit the sol-film on the cellulose surface. The TIO _ 2 carbon nanofibers and TIO _ 2 nanotubes were prepared by calcining in nitrogen atmosphere and air atmosphere respectively. The structure and photocatalytic properties of the samples prepared under different conditions were investigated by means of FT-TR,XRD,SEM,TGA and BET and methylene blue degradation experiments. It was found that the TIO _ 2 gel layer calcined in nitrogen atmosphere was transformed into anatase crystal form and completely attached to the surface of carbon nanofiber. The microstructural characteristics of cellulose were copied and the immobilization of catalyst was successfully realized. The catalyst sample has a large specific surface area and a good crystal phase structure, while the doped cerium element further improves the crystallization characteristics and photocatalytic performance of the sample.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ352.1;TB34

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