Using a novel very sensitive radiotracer technique, we have measured the co
ndensation coefficient C of Ag on several polymers. C shows an extreme vari
ation ranging from close to unity for polyimide to values as low as 0.002 f
or Teflon AF(TM) at room temperature. C decreases strongly at elevated temp
eratures and exhibits a drop somewhere below the bulk glass transition temp
erature. The observed angular distribution of reemitted atoms does not depe
nd on the angle of incidence and has a cos theta form. This, among other ar
guments, suggests them to be adsorbed at the surface prior to reemission. N
ucleation, studied on a polycarbonate, turned out to take place at preferre
d sites.