Initial testing and a laboratory manual for the Micromeritics Gemini VI physisorption system
Kemp, S.J.; Turner, G.; Wagner, D.. 2009 Initial testing and a laboratory manual for the Micromeritics Gemini VI physisorption system. Nottingham, UK, British Geological Survey, 33pp. (IR/08/086) (Unpublished)Before downloading, please read NORA policies.
This report describes initial testing of the newly acquired Micromeritics Gemini VI physisorption system as part of the Laboratory Operations Programme’s Maintenance and Development of Capability (MaDCap) project. The report firstly introduces the technique of surface area analysis and BGS’s capabilities and then proceeds to present a user manual and suggested working methodologies for the new system. The report also presents data produced from a range of sample types including soils, mudstones and experimental starting materials to demonstrate the capabilities of the system to various BGS project leaders. Reliable data were generated in all cases, although very low surface areas close to the system’s lowest detection limit (c.0.05 m2/g) appear to be slightly less reliable. Multi-point BET analyses provide more accurate but slightly larger surface areas than those derived from single-point measurements for the same sample. On the basis of the samples tested here, sample heterogeneity would not appear to be a significant problem for ‘routine’ samples. However, analysis of ground material from the same samples revealed a wider spread of results. Sample heterogeneity may also be a greater problem when analysing very low surface area materials. For surface areas in the range 0.1-60 m2/g, errors appear to be better than ±2% (of the value) which concurs with data for the supplied carbon black Surface Area Reference Material. For lower surface areas (<0.1 m2/g) these errors can increase to ±6%. Analysis of soils suggests that the technique may be useful in characterising black carbon contents. Interestingly, the surface area for the ground materials appears lower than that produced for the corresponding <2 mm size fraction. This is the reverse of the expected result and requires further investigation. For mudstone samples, surface areas appear to correspond to the total concentration of clay minerals present with some influence from the presence of smectite. Surprisingly, the lowest surface area in this suite of mudstone samples was produced by the Bentonite (?Sweden) sample. This may relate to the degassing regime employed. Users are advised to follow the protocols outlined in this report and the analysis programs setup. It is also advised that filler rods are used to reduce free-space and error for low surface area materials (<50 m2/g). Further work, beyond the scope of this initial study, is required to identify the effects of different degassing routines and the differing surface areas obtained when analysing ground and crushed samples. Additional work is also necessary to more fully explore the pore size distribution functions of the physisorption system.
|Item Type:||Report (UNSPECIFIED)|
|Programmes:||BGS Programmes 2008 > Laboratory Operations|
|Additional Information:||This report was made open 20.09.12 by author. This item has been internally reviewed but not externally peer-reviewed|
|Date made live:||20 Sep 2012 15:00|
Actions (login required)