Gaseous hydrogen, H2, has many physical properties that allow it to move rapidly into and through materials, which causes problems in keeping hydrogen from materials that are sensitive to hydrogen-induced degradation. Hydrogen molecules are the smallest diatomic molecules, with a molecular radius of about 37 x 10-12 m and the hydrogen atom is smaller still. Since it is small and light it is easily transported within materials by diffusion processes. The process of hydrogen entering and transporting through a materials is generally known as permeation and this section reviews the development of hydrogen permeation barriers and barrier coatings for the upcoming hydrogen economy.
Revised: January 7, 2011 |
Published: January 1, 2008
Citation
Henager C.H. 2008.Hydrogen Permeation Barrier Coatings. In Materials for the Hydrogen Economy, edited by RH Jones and GJ Thomas. 181-190. Boca Raton, Florida:CRC Press.PNNL-SA-52988.