Diffusion coefficient for peregal O-20 desorpted from its monolayer

From the dynamic surface pressure of Peregal O-20 spreading monolayres, the variation of the model material sur f ace concentrations was obtained by extrapolating method.Taking advantage of the relation Π t～ c , the diffusion coefficients ( D 0) of the Peregal O-20 desorpted from the surface at air-water interface to the aqueous bulk was calculated.The order of D 0 was 10 -4～10 -3 cm2/s.The initial surface concentration is the key factor of influence on the diffusion coefficients of Peregal O-20.