Session 7: Discussion

H E EVANS CEGB Berkeley Nucl Labs

Mr Longson suggested that the wetting process involves displacement of adsorped gaseous atoms. Does he know of any work which illustrates the effect of different adsorped gases on rates of wetting?

B LONGSON

No, but this would be an interesting series of

experiments, as also would an experiment in

vacuum through a very high vacuum might be

needed to remove all adsorped gases.

C C ADDISON University of Nottingham

There can be considerable hysteresis effects

in measurements of advancing contact angles.

Was there any evidence of this in the measure

ments in paper 27?