This paper analyses the growth of the adsorbed layer during the course of \(N_2\) adsorption verified in two types of elliptical pores, oblates and prolates, by means of the Broekhoff de Boer theory. The information provided by the value of the thickness of the adsorbed layer permits to characterize the geometrical features of the liquid–vapour interface at every stage of the isotherm, prior and at the onset of capillary condensation. The features of the liquid–vapour interface that are characteristic of the instability at the onset of capillary condensation were identified. Additionally, the critical ellipsoidal pore sizes were calculated, thus identifying the limit of stability for the formation of the liquid–vapour interface during \(N_2\) adsorption.

本文利用 Broekhoff de Boer 理论分析了在扁形和扁长形两种椭圆形孔中证实的\(N_2\)吸附过程中吸附层的生长。由吸附层厚度值提供的信息允许表征在等温线的每个阶段、毛细管冷凝之前和开始时的液-气界面的几何特征。确定了在毛细冷凝开始时具有不稳定性特征的液-气界面特征。此外，计算了临界椭球孔径，从而确定了\(N_2\)吸附过程中液-气界面形成的稳定性极限。