非均匀多孔介质表面变压过程的分形特征研究

STUDY ON THE STRUCTURE AND FRACTAL CHARACTERISTICS OF POROUS MATERIAL

多孔物质的表面结构可以用分形维数 D来表征 ,D与微孔结构存在对应的关系 ,不同的表面分形维数对应不同的微孔结构 .详细讨论了分形维数和微孔结构随压力的变化规律 .随着压力的增大 ,多孔介质表面形成更小的吸附微孔 ,孔径分布广 ,表面变得更粗糙 ,分形维数增大 ,至到趋于稳定值 .

Fractal dimension ( D ) can be used to characterize the surface structure of porous solids. Different fractal dimensions correspond to the different micropore distributions. The relationship between the D and the micropore structure is derived. The influences of pressure on the fractal dimension and the structure of micropore are discussed in details. With the increase of the pressure, the micropores become smaller; the pore distribution becomes wider; the surface becomes coarser and the D increases up to a constant value. By using the fractal dimension, the characterization of the surface structure of porous solids becomes simple.\;