IMPERFECT WETTING OF HYDROGEN IN ZEOLITE

We have considered the theoretical dependencies of the amount of super cooling of liquid hydrogen as a function of pore size for constrained geometries in order to compare the different mechanisms for supercooli ng that can be observed: notably the inhibition of nucleation in small geometries and the use of surfaces for which there is imperfect wetti ng. Analysis of the dependence of the observed supercooling reported e lsewhere for molecular hydrogen and hydrogen deuteride on the pore siz e in zeolites supports the view that imperfect wetting occurs for smal l pores that have rough surfaces and dimension less than approximately 10 Angstrom.