Spreading Coefficients of Aliphatic Hydrocarbons on Water

Experiments have been performed to determine the equilibrium spreading coefficients of some aliphatic hydrocarbons (C 6C 10) on water. The thickness of a discrete lens of each hydrocarbon sample floating on a stagnant water pool was measured interferometrically and used to calculate the spreading coefficient of the hydrocarbon with the aid of Langmuir's capillarity theory. The dependences of the spreading coefficient, thus observed, on temperature (0-50°C) and on the number of carbon atoms in the hydrocarbon molecule are in qualitative agreement with the predictions based on the Lifshitz theory of van der Waals forces.