Neutron reflection experiments have been conducted on the adsorption o
f gelatin to polystyrene, and the effect of sodium dodecyl sulphate (S
DS) on the adsorbed layer. The substrate for adsorption was a silicon
crystal spun-coated with a film of polystyrene. This was placed in con
tact with different concentrations of gelatin solution between 0.0001%
and 0.5% by weight, and reflectivity profiles obtained at 35 degrees
C Rinsing the gelatin layer with water was found to remove some materi
al from the surface of the layer, but not significantly change the com
position. The addition of SDS solutions decreased both the thickness a
nd composition of the gelatin layer. The most applicable model for the
combined system was found to be gelatin and SDS combined in a single
layer with exponential profile.