POLYMOLECULAR ADSORPTION AND CAPILLARY CONDENSATION IN NARROW SLIT PORES
POLYMOLECULAR ADSORPTION AND CAPILLARY CONDENSATION IN NARROW SLIT PORES
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DOI：
10.1016/0021-9797(76)90298-8
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发表时间：
1976-01-01
影响因子：
9.9
通讯作者：
CHURAEV, NV
中科院分区：
文献类型：
--
作者：
DERJAGUIN, BV;CHURAEV, NV
计算了窄缝中的毛细管冷凝和多分子吸附，其中表面力场彼此重叠。计算是根据宏观色散力理论和自由表面孤吸附层等温线进行的。研究表明，在间隙相互吸引的作用下，多分子吸附膜的厚度早在其厚度接近平缝半宽之前就失去了稳定性。这导致平面平行狭缝集合中毛细管冷凝的滞后。在具有强吸附质-吸附质相互作用的系统的情况下，已经检测到狭缝孔尺寸的下限的存在，其中毛细管弯月面可以与吸附膜共存。当狭缝宽度小于临界宽度时，弯液面可能与狭缝的“干燥”表面形成有限的接触角。因此，已经给出了平坦表面狭缝孔整体中毛细管冷凝的下限的解释。在强吸附质-吸附剂相互作用的情况下，在所用方法的范围内，在任何宽度的狭缝中，弯液面与吸附膜的共存都是可能的。在获得的毛细管冷凝数据的基础上，分析了狭缝孔尺寸计算中要输入的表面力效应的修正值。在楔形狭缝中，除了毛细管滞后的下限之外，还存在上限。
Capillary condensation and polymolecular adsorption in narrow slits has been calculated, where the fields of surface forces overlap one another. The calculations were carried out on the basis of macroscopic theory of dispersion forces and the isotherms of lone adsorption layers at the free surface. It has been shown that under the effect of mutual attraction through a gap, polymolecular adsorption films lose their stability long before their thickness has approached the half-width of a flat slit. This results in hysteresis of the capillary condensation in an ensemble of plane-parallel slits.In the case of systems having strong adsorbate—adsorbate interaction, there has been detected the existence of the lower limit of sizes of slit pores, wherein the capillary meniscus can coexist with adsorption films. With a slit width smaller than the critical one, the meniscus is likely to form a finite contact angle with “dry” surfaces of a slit. Thus an explanation has been given of the lower limit of the capillary condensation in an ensemble of flat-surface, slit pores. In the case of strong adsorbate—adsorbent interaction, the coexistence of meniscus with adsorption films within the scope of the approach used is possible in slits of any width.The value of corrections for the surface forces effect to be entered in the calculations of slit pores dimensions has been analyzed on the basis of the capillary condensation data obtained.In wedge-shaped slits there also exists, besides lower limit the upper limit of capillary hysteresis.