【作者】 钟磊；

【导师】 沈青；

【作者基本信息】 东华大学 ， 材料物理与化学， 2006， 硕士

【摘要】 作为一种新型的无机膜,由含碳物质经高温热解炭化制成的炭膜具有许多非常好的特点。如:耐高温、耐酸碱、具有较高的机械强度、理想的渗透性、分离性和吸附性能。而且,通过对表面和孔结构进行修饰还可以进一步改变炭膜的特点。自上世纪80年代开始,炭膜在国外得到了很快的发展,用于液体分离的微滤炭膜已经有了工业化的报道,但气体分离方面的炭膜仍处于实验室阶段。 目前,炭膜的制备成本比较昂贵,这既限制了炭膜在大规模膜组件中的应用,又限制了它的工业化生产。因此,寻找一种既具有良好的分离性能又经济可行的膜材料是炭膜研究领域的主要研究方向之一。木质素是自然界中数量仅次于纤维素的一类自然资源,却曾经由于作为木材水解工业和造纸工业的副产物,得不到充分利用,变成了环境污染物。考虑到未来环境与资源的需要,加强和重视木质素的研究是非常迫切的。 以木质素为基本原料和致孔剂,本文介绍了木质素制备炭膜的过程及所得到的炭膜的基本性能。首先研究了木质素的一些基本性能如表面能等。实验发现木质素是一种低表面能的物质,其表面能约为21-22mJ/m~2。然后,进一步研究了木质素在HCl溶液中的溶解行为。通过粒度仪与扫描电镜测试发现木质素在HCl溶液中是一个溶胀的更多还原

【Abstract】 Carbon membrane, a kind of inorganic membrane, is prepared by the pyrolytic carbonization of substance which contains carbon. It has high temperature-resistant, acid and alkali-resistant properties and high performances of mechanical intensity, osmosis, selectivity and sorption. In addition, its surface and microstructure can be modified and improved. Since 1980s, carbon membrane has been rapidly developed abroad. Carbon membrane for micro-filtration has been reported in commercial application, while carbon membrane for gas separation is still in the laboratory scale.Currently, the cost of carbon membrane is relatively high which limits its application in extensive subassembly and industrialized manufacture. Therefore one of the main research fields in carbon membrane is to find a membrane raw material. This material should be feasible, cheap, and have good sorption property. Lignin is a kind of natural resource next to than fiber in amount exists in nature. As thebyproducts of wood hydrolysate and paper making industry, it used to pollute environment because it hasn’t been fully used. Considering future environment and resources, it is essential to pay more attention to the exploiture of lignin.This paper introduced the preparation process and basic performance of carbon membranes which were synthesized by using lignin as one of raw materials and pore-forming agent. Firstly, some basic properties of lignin such as surface energy were researched. The experiment showed the surface energy of lignin was about 21-22 mJ/m~2. It indicated that lignin was a low surface energy substance. Secondly, the dissolution behavior of lignin was studied. Using granularity instrument and SEM, we knew that lignin was swollen in HC1. The external shape of lignin was modified markedly in HC1 which was changed from rotundity to rectangle. And FTIR showed the structure of lignin in HC1.Lignin- phenol-formaldehyde resins were prepared by using phenol, formaldehyde and lignin with a content of 8 14 20 . Then the resins were coated on the glass board and furtherly pyrolyzed in a flowing nitrogen atmosphere. Thus the carbon membranes were obtained.From the analysis of carbon membrane micro-structure by using SEM, we can observe that the carbon membranes had apparent pore size of micro-nanometer. Therefore it meant that lignin maybe act as a pore-forming agent in the carbon membranes. For example, when thelignin content was 6%, the micro-size of pore shifted from 1.1 to 2.6um and the nano-size ranges from 120 to 320nm. The pore size was closely related with lignin content. So it probably also meant that the pore structure of carbon membrane may be controlled by adjusting the lignin content. The membrane adsorption ability and thickness was increasing with the increase of lignin content. In addition, the lignin content also had effluence to electric resistance of membrane. Through CP/MAS I3C NMR spectrum we can find that carbon membranes still had a feature of phenol-formaldehyde resin. So the carbon membranes had a possibility to be improved by prolonging carbonization time.更多还原