量热法测定固体的比表面

MEASUREMENT OF SURFACE AREA OF SOLID WITH MICROADSORPTION FLOw CALORIMETRY

1 前言固体的比表面积是一个重要的物理化学参数.在石油开采中,液-固或气-固的相互作用对采收率有极大的影响.油砂的比表面是油藏工程设计的重要参数.油砂的主要成份为各种金属氧化物的混合物,如能准确测定各氧化物的比表面,则应能准确测定油砂的比表面。常用的固体比表面测定方法有多种,由浸润热或吸附热求算固体的比表面的量热法也经常运用.

Specific surface area of solid is an important physico-chemical parameter. This kind of information is frequently required in describing the interactions between liquid and solid or gas and solid. In this paper, two equations which can be usedto calculate the surface area of solid powder directly from the adsorptions enthalpy ofliquid on solid are derived from the liquid solid surface state equations. Surfaceareas of eight metallic oxides have been calculated from the adsorption enthalpiesmeasured by means of LKB-2107 Microadsorption Flow Calorimeter. For comparison,these surface areas have also been measured by using traditional BET (N_2 adsorption)method. The results obtained by using these two methods agree quite well.