In Situ Monitoring of Adsorption and Desorption of n-Heptane on Porous Silica by Positron Annihilation Lifetime Spectroscopy

Abstract:

Article Preview

Positron annihilation lifetime spectroscopy study of n-heptane adsorption and desorption on silica gel Si-60 gives insight into a free volume evolution during those processes. Analysis of the lifetime distribution allows to ascribe particular ortho-positronium components to silica walls, mesopores and n-heptane. Hysteresis loop of the intensities of the mesopore and n-heptane related components similar to classic adsorption/desorption isotherms is observed. Transition from an adsorbate multilayer structure to liquid when pores become completely filled, manifests itself as an intensity change. Kinetics of desorption and adsorption studies allows to determine the time of reaching the equilibrium by the Si 60–n-heptane system at various pressures.

Info:

Periodical:

Edited by:

Jozef Krištiak, Jan Kuriplach and Pradeep K. Pujari

Pages:

207-211

DOI:

10.4028/www.scientific.net/MSF.733.207

Citation:

R. Zaleski et al., "In Situ Monitoring of Adsorption and Desorption of n-Heptane on Porous Silica by Positron Annihilation Lifetime Spectroscopy", Materials Science Forum, Vol. 733, pp. 207-211, 2013

Online since:

November 2012

Export:

Price:

$35.00

[1] S. J. Gregg, K. S. W. Sing: Adsorption, Surface Area and Porosity, 2nd edition, Academic Press, New York, (1982).

[2] A. Shukla, M. Peter, L. Hoffmann Nucl. Instrum. Methods Phys. Res., Sect. A Vol. 335 (1993) pp.310-317.

[3] J. Kansy Nucl. Instrum. Methods Phys. Res., Sect. A Vol. 374 (1996) pp.235-244.

[4] T. Goworek, W. Górniak, J. Wawrysczuk Nucl. Instrum. Methods Phys. Res., Sect. A Vol. 321 (1992) pp.560-570.

[5] R. Zaleski Acta Phys. Polon. A Vol. 110 (2006) pp.729-738.

[6] C. Dauwe, B. Van Waeyenberge, D. Segers, T. Van Hoecke, J. Kuriplach J. Radioanal. Nucl. Chem. Vol. 210 (1996) pp.293-308.

[7] S. Mariazzi, A. Salemi, R. S. Brusa Phys. Rev. B: Condens. Matter Mater. Phys. Vol. 78 (2008) pp.085428-085428.

[8] R. Zaleski, W. Dolecki, A. Kierys, J. Goworek Microporous Mesoporous Mater. Vol. 154 (2012) pp.142-147.

DOI: 10.1016/j.micromeso.2011.08.032

In order to see related information, you need to Login.