Gibbs energy additivity approaches in estimation surface tension of fatty acids

Surface tension is important to ensure the efficiency of industrial operation units involving chemical reactions and extractive processes that use these compounds as solvents. In this work, the surface tension of fatty acids (FA) is correlated to Martin's rule of free energy additivity for estimating surface tension. The proposed equations for estimating the surface tension of FAs are correlated to the number of carbon atoms (z), the number of double bond (s) (nd) and temperature (T) to γ = 69.065−1.3614z−0.13895T+0.005209zT+6.24n_d−0.01612n_dT. The proposed equations are easy to use and the estimated values of surface tension of FA at different temperatures agree well with the literature values. (paper)