冲洗色谱特征点法测定表面分形维数初探

在用非线性气相色谱测填料表面分形维数中，首次运用气固色谱（ＥＣＰ法（ｅｌｕｔｉｏｎ ｂｙ ｃｈａｒａｃｔｅｒｉｓｔｉｃ ｐｏｉｎｔｓ ｍｅｔｈｏｄ），测定了正戊烷、正已烷、正庚烷３种烷烃在不同颗粒大小的硅胶表面的吸附等温线，通过拟合Ｌａｎｇｍｕｉｒ方程，求出单分子饱和吸附容量，并采用单分子层吸附的分形模型，求得硅胶的发形维数，提供了一种测定表面分形维数的新方法。

Preliminary Results on Surface Fractal Dimension Study by ECP Method

An ECP(elution by characteristic points) method in nonlinear gas chromatography is described for the determination of the surface fractal dimension of silica gel aggregates. The adsorption isotherms of n _ pentane, n _ hexane and n _ heptane on silica gel of various particle sizes were determined by the ECP method. After curve fitting with the Langmuir equation, the mono _ molecular layer adsorption capacity could be obtained. A quatitative relationship exists between the surface fractal dimension and the mono _ molecular layer capacity, provided the molecular cross _ sectional areas of n _ alkanes are known. With the aid of a monolayer fractal dimension model, the surface fractal dimension of silica gel can be computed.