用于测定介孔的Kelvin方程及其修正述评

介绍了物理吸附法评价介孔材料孔结构参数的理论基础、孔介质模型及吸附质对测量结果准确性的影响因素.讨论了 Kelvin 公式,以及从不同方面对 Kelvin 公式进行的修正,并以此为基础,评述采用物理吸附法测定介孔材料各种孔结构测试方法,着重探讨物理吸附法的理论基础、模型建立及其不足之处,分析和探讨介孔材料孔结构表征中存在的问题及原因,为建立新的理论模型探讨思路与可能.

Review of Kelvin's Equation and Its Modification in Characterization of Mesoporous Materials

Physical and mathematical models as well as calculation methods of nitrogen bed on porous media have been introduced to evaluate the structural parameters of mesoporous materials.Kelvin's equation is a link between the relative adsorbate pressure,the mean pore radius,and pore capillarity on the basis of macroscopic capillary condensation.However,Kelvin's equation has been identified that it underestimates the calculated pore size of a material especially in the boundary of pore size which is between 2 and 4 nm. Various modifications on Kelvin's equation were mentioned in order to develop a new model to improve the accuracy of pore size calculation.The problems on conventional mathematical models were analyzed and discussed.A number of calculation methods on physisorption and pore size,especially fundamental theories of physisorption,basis of models and their deficiencies are reviewed.It can provide guidance on developing a modified Kelvin's equation for pore size calculation.