Fractality of Porous Silicas: A Comparison of Adsorption and Porosimetry Data

✍ Scribed by Alexander Yu. Fadeev; Olga R. Borisova; George V. Lisichkin

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 94 KB
• Volume: 183
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1996.0511

✦ Synopsis

sions given in (10,11). The authors (16, 17) suggest that The fractal dimensions of seven porous silicas were determined solids that are synthesized via a sol-gel procedure can have by means of gas adsorption, chemisorption of chlorosilanes, and a fractal surface only as an exception but not as a rule. mercury porosimetry. The silicas under investigation are shown The fractality of silicas and other porous solids was studto be surface fractals in the range of cross-sectional areas from ied by means of several physicochemical techniques: adsorp-0.162 (N 2 ) to 1.450 sq. nm ((C 6 H 13 ) 3 SiCl). The surface fractal tion from gases and liquids (4, 18-22), mercury porosimedimensions obtained range from 2.05 to 2.90. On the other hand, try (4, 6, 23), small angle X-ray scattering (24-26), elecmercury porosimetry data show that the silicas studied can be tron microscopy (27), energy transfer between adsorbed hardly considered as pore fractals within the range of a pore radius molecules (28-34), and others. A central technique in the from 3.5 to 1000 nm. The apparent contradiction is discussed in the text.