Preparation and characterization of silica-modified activated carbon fibers

✍ Scribed by Akihiko Matsumoto; Masatoshi Ruike; Takaomi Suzuki; Katsumi Kaneko

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 582 KB
• Volume: 74
• Category: Article
• ISSN: 0927-7757
• DOI: 10.1016/0927-7757(93)80394-t

✦ Synopsis

Activated carbon fibers (ACFs) have relatively uniform slit-shaped micropores.

A silica film was deposited on the micropore walls by adsorption of SiCl, on the micropores, then successive reaction of adsorbed SiCl, with H,O, and heat treatment using a greaseless vacuum line. The silica-modified ACFs were characterized by N, adsorption, thermal analysis, X-ray diffraction, electron-probe microanalysis, scanning electron microscopy and diffuse reflectance infrared Fourier transform spectroscopy (DRIFT). No silica particles on the ACF surface were observed by the scanning electron microscope with a resolution of IO nm. The modification of ACF by silica did not change the type of N, adsorption isotherm: the silica-modified ACF was also microporous.

The silica modification slightly decreased the micropore width by 0.2 nm from the t-plot analysis. The apparent surface area and micropore volume of the silicamodified ACF were more than 1100 m2 g-' and 0.68 ml g-', respectively. The silica-modified ACF can adsorb more than 400 mg g-' of H,O at 303 K at a relative pressure of 0.7. The DRIFT spectra suggested that the silica film on the ACF is thin.