Abstract: As the core components of environmental AFFF, one dimensional spreading performance of four carbon chain surfactant (FC- 4) solutions on cyclohexane, n- heptane, aviation kerosene, solvent oil and 0# diesel were studied. A certain amount of FC- 4 surfactant and 1- hexanesulfonic acid sodium were mixed in the ratio of 1∶1, and the FC-4 solution with concentration of 20 mmol/L was prepared according to CMC value of the compound system. The relationship between spreading length and time of liquid film at 25 ℃ was obtained and was fitted by power exponential function of L=mtn . The relationship between spreading length and spreading time of surfactant solution on different oil surface was obtained. By calculating, the root mean square deviation (RMSD) between experimental values and theoretical values are less than 1.43, which shows a good agreement with experimental values and theoretical values. The power exponent function can be used to predict the spreading process of surfactant solution on fuel oil.

Key words: fluorine surfactant, spreading rate, spreading length, spreading coefficient