The surface properties, fragmentation and the microbial attachment to the surface were be observed in the scanning electron microscopy (SEM). SEM observations were performed using a Desktop SEM (Phenom ProX, Fondis Bioritech, France) with an acceleration voltage ranging between 5 and 10 kV secondary electrons. Samples were directly mounted on stub using carbon conductive tape and then coated with Gold/Palladium during 45 s at 20 mA (4 nm thick) by ion sputtering (Mini Sputter Coater SC7620, Quorum Technologies Ltd, UK).