4(%3)3 - Ecole nationale supérieure de chimie de Montpellier

The wafers thus obtained were then kept in vacuum for 24 hours to dry followed by immersionin ultrapure water for few hours. The immersion in water facilitates an easy separation of copolymer filmfrom the wafer and loading onto a polyester non-woven fabric. Fabric supported membranes of 4.1 cm 2area were cut from these films thereafter for further experiments.2.3 MEMBRANE CHARACTERISTICSThe top surface analysis by Atomic Force Microscopy (AFM) of the films revealed a morphologymarked by an assembly of spherical micelles having an average diameter of 50 nm with a narrow sizedistribution (Figure – 2.3a,b). Moreover, the surface of film seemed to be very flat as indicated by 3DAFM image (Figure – 2.3c) with a z value of 20 nm, which is approximately half of the diameter of theparticles and indicates a rather dense packing of the micelles.Figure – 2.3: Atomic Force Microscopy images obtained for the copolymer micelles assembly, a) closely packedmicelles with monomodal size distribution (inset), b) enlarged view of the micelles, c) z-profile image for the surfaceshowing a relative smooth topography and tight packing49