压汞法测量玻璃毛细孔中的水和正癸烷

水在固体表面或在毛细孔玻璃中的性质,一直是人们感兴趣的问题。而靠近固体表面的水,其性质不同于体相(Bulk)水,也是为人所知的事实。已经知道,邻近水的热容、密度、粘度、电导及结构等都不同于体相水。但邻近水的厚度究竟为多少,或者说,这种固体表面对水的性质影响究竟是长程的还是短程的,目前还没有统一的结论。用压汞法测量多孔物质的孔体积,是人们已熟知的方法,但还没有人将其用于测量液体在毛细孔中的体积、密度等行为。我们尝试了用压汞法,测量具有确定孔径的毛细孔玻璃(CPG),在吸附了不同量水后孔体积的变化,进而计算了不同吸附层的水在CPG中的体积、密度。此外还测定了载有不同量正癸烷后,CPG孔体积的变化。

MERCURY POROSIMETRY FOR THE DETERMINATION OF WATER AND n-DECAN IN POROUS GLASS

Structuring of water on glass surface has been widely reported. There exists adebate on the thickness of the structured water layer on these surfaces, sometimeslong-range,sometimes short-range structuring of the surface water was inferred. Weused a porosimeter to measure the pore volume of controlled pore glass with poreradius 12. 1 nm, which had pre-adsorbed various amount of water, and to study thebehaviour of water on controlled pore glass surfaces.It has been found that the first2-3 layers of the adsorbed water were modified from the bulk water. The thicknessof this modified water layer on the controlled pore glass was calculated to be about5 A and the density of this water was much higher than that of the bulk water.Therest of the adsorbed water was similar to bulk water. No abnormal phenomena was found for n-Decan in the controlled pore glass.Forany amount of adsorbed n-Decan, they had similar property as that of the bulkn-Decan.