2.8. Contact angle measurements
Polystyrene samples of 3 cm2 were cleaned as described by
Zeraik and Nitschke (2010). The samples were conditioned with the
biosurfactants for 24 h at room temperature, washed with 10 ml of
water and left to dry in a desiccator for 24 h. As control, samples of
polystyrene were immersed in distillated water for 24 h. The
contact angle ofwaterwas assessed by the sessile drop technique at
20 C using a drop volume of 4 ml on a Contact Angle System (CAM
200- KSV).