Physical Adsorption Measurement: Preliminaries
The adsorbed amount as a function of pressure can be obtained by volumetric (manometric) and gravimetric methods, carrier gas and calorimetric techniques, nuclear resonance as well as by a combination of calorimetric and impedance spectroscopic measurements (for an overview see refs [1–3]). However, the most frequently used methods are the volumetric (manometric) and the gravimetric methods. The gravimetric method is based on a sensitive microbalance and a pressure gauge. The adsorbed amount can be measured directly, but a pressure dependent buoyancy correction is necessary. The gravimetric method is convenient to use for the study of adsorption not too far from room temperature. The adsorbent is not in direct contact with the thermostat and it is therefore more difficult to control and measure the exact temperature of the adsorbent at both high and cryogenic temperatures. Therefore, the volumetric method is recommended to measure the adsorption of nitrogen, argon and krypton at the temperatures of liquid nitrogen (77.35 K) and argon (87.27 K) .
KeywordsAdsorbed Amount Gravimetric Method Magnesium Stearate Porous Solid Repetitive Cycling
Unable to display preview. Download preview PDF.
- 2.Mikhail R.Sh. and Robens E. (1983) Microstructure and Thermal Analysis of Solid Surfaces, Wiley, Chichester.Google Scholar
- 6.Rouquerol F., Rouquerol J. and Sing K.S.W. (1999) Adsorption by Powders & Porous Solids, Academic Press, London.Google Scholar
- 9.a)BAM: Bundesanstalt für Materialforschung und –prüfung, Richard-Willstätter-Str. 11, D-12489 Berlin, Germany, http://www.bam.de.
- b)NIST: National Institute of Standards and Technology, Gaithersburg, MD, USA, http://ts.nist.gov/ts/htdocs/230/232/232.htm
- c)LGC: LGC Promochem, Queens Rd, Teddington, Middlesex TW11 0LY, UK, http://www.lgcpromochem.com
- d)IRMM: Institute for Reference Materials and Measurements, Reference Materials Unit, attn BCR Sales, Retieseweg, B-2440 Geel, Belgium, http://www.irmm.jrc.be.
- 10.Robens E., Krebs K-F., Meyer K., Unger K.K. and Dabrowski A.(2002) Colloids Surf. A: Physicochemical and Engineering Aspects, 253.Google Scholar