Analysis Gases

Determining what gas to use for analysis.

 

Helium is the most used gas for pycnometry due to its ideal behavior; however, there are times where other gases can be substituted for helium.

 

Helium has the ability to permeate into pores that are closed from the surface and interacts with some organic materials and microporous carbons.

 

The solution is to use another gas such as nitrogen, argon, or air. Larger molecules such as sulfur hexafluoride can be used to include the volume of very small pores in volume results.

 

Care should be taken to select a gas that does not interact with the sample material.

A picture containing colorfulness, sphere, light

Description automatically generated