膨胀石墨的孔隙结构及其在液相吸附吸着时的变化  

Pore Structure of Exfoliated Graphite and Its Varieties of Liquid Sorption

作　　者：兆恒[1] 周伟[1] 曹乃珍[1] 沈万慈[1] 郑永平[1] 

机构地区：[1]清华大学材料科学与工程系,北京100084

出　　处：《材料科学与工程》2002年第2期153-155,159,共4页Materials Science and Engineering

基　　金：国家自然科学基金资助项目 (50 1 72 0 2 7) ;清华大学 985计划;清华大学实验基金资助项目

摘　　要：用氮气吸附法和压汞法测量膨胀石墨 (EG)的孔结构 ,用SEM观察EG颗粒间的孔隙结构和EG的孔隙率。实验得到 ,EG颗粒间的孔隙率占 85 %以上 ,EG颗粒开放孔的孔隙率占 13%以上 ,EG颗粒的闭合孔的孔隙率不到 1%。研究得到 ,EG颗粒的孔隙分为四级结构 ,包括颗粒片断间的V型开放孔 ,尺度数十到数百微米 ;与蠕虫状颗粒轴向垂直的几个到数十微米的柳叶状孔 ;垂直颗粒轴向的片层面上的零点几到几个微米的孔以及BET测量得到的纳米级孔。EG的比表面积 <10 0m2 g。在液相吸附 吸着作用中 ,由于EG与液相的界面张力作用 ,EG颗粒中的孔隙发生变形以及使颗粒碎裂。The pore structure of EG was measured by nitrogen adsorption and mercury porosimeter methods.The space around EG particle was observed by SEM and the porosity of EG was measured by pycnometer method.The results showed that the porosity of EG grains was more than 85%, the porosity of open pore and close pore in EG was more than 13% and less than 1%,respectively.\;The present work divides the pores of EG into 4 levels.At level 1,EG particle contains V\|type open pores with dimension about several hundreds micrometer; at level 2,the wellowleaf\|type pores are perpendicular to the axis of worm grain with dimension of a few micrometers,in which most of pores are open;at level 3, the pores with dimension from 0.1 to several μm on the surface of lamella is perpendicular to the axis of worm grain;and at level 4, the pores with nanometer scale is only measured by nitrogen adsorption method.The specific surface area of EG is less than 100m\+2/g.\;During liquid adsorption/absorption process,the pores of EG grains are deformed and grains are shattered by the surface tension between EG and liquid.Larger the absorption amount is,more remarkable the effect is.

关 键 词：液相吸附 膨胀石墨 孔隙结构 孙隙率 吸附性能 氮气吸附法 压汞法 

分 类 号：TQ165[化学工程—高温制品工业] O647.3[理学—物理化学]