常温干燥法制备纳米炭粉

以煤焦油沥青为原料,浓硫酸和浓硝酸为氧化剂,利用溶胶-凝胶方法制备水性中间相沥青.将水性中间相沥青溶解于氨水中得到水相炭基凝胶,经过乙醇与水交换后进行常温干燥和热处理制备纳米炭粉.利用FT-IR光谱、TG、XRD和TEM等分析手段对水性中间相沥青、纳米炭原粉以及纳米炭粉进行了表征.结果表明:采用常温干燥方法制备纳米炭粉是可行的,制得的纳米炭粉粒度均匀、规则,形状近似于球形,平均粒径为20 nm左右,其炭结构为无序的乱层石墨结构.在沥青与混酸氧化过程中,主要发生硝化、氧化、磺化反应;纳米炭原粉的热解过程分为脱醇脱水、预热解、强烈热分解和结构重排等四个阶段.

Preparation of nano-carbon powders drying at room temperature

The nano-carbon powders were prepared by sol-gel method,in which the coal tar pitch was first oxidized into aqua-mesophase pitch(AMP) by mixtures of concentrated sulfuric acid and nitric acid,and then the AMP was dissolved in aqueous solution of ammonia hydroxide to form the carbonaceous hydrogel,which was directly exchanged with ethanol to remove water and dried at room temperature.The AMP,the primary nano-carbon powders and their heat-treated products were characterized by FT-IR,TG,XRD and TEM method.The results show that the nano-carbon powders can successfully be prepared by drying at room temperature;the balllike nano-carbon powders are well distributed with an average size of about 20 nm and have a turbostratic carbon structure.In the reaction of coal tar pitch with mixing acids,the reaction of nitration,oxidation and sulfonation was mainly involved.The pyrolysis process can be divided into four stages,including removal of ethanol and water,pre-pyrolysis,pyrolysis and rearrangement of carbon structure.