Evaluation of cold plasma effect to achieve fullerene and zinc oxide-fullerene hydrophobic thin films

C-60 and C-60-ZnO thin films were synthesized by spray pyrolysis method, and structural, chemical, optical and self-cleaning characterizations of this nanocomposite were performed before and after plasma treatment. The C-60 thin film has a very wide peak in the range of 2 theta = 15-35 degrees, which indicates the amorphous structure of this film. After plasma treatment, fullerene peaks appear at angles of 2 theta = 13.94, 17 degrees. Fullerene peaks in the C-60-ZnO and C-60 thin films are similar and are seen exactly at the same angles. The location of zinc oxide peaks did not change before and after plasma treatment. The presence of fullerene peaks in the studied thin films after plasma treatment indicates that the crystallographic quality of C-60 and ZnO-C-60 thin films has improved. FESEM image of fullerene thin films before and after plasma treatment shows that fullerene nanoparticles are almost spherical. After plasma treatment, the particle size is reduced, and all particles are below 50 nm with spherical shape. FESEM images of C-60-ZnO thin film after plasma treatment show both fullerene and zinc oxide particles become smaller and the particles have a uniform distribution. The results of FTIR chemical analysis in thin film samples show the chemical bonds of the nanocomposite before and after plasma treatment. In AFM images, the surface of the C-60 thin film is smooth and uniform before plasma compared to after plasma processing. Also, in C-60-ZnO composite, the grain size after plasma treatment is much larger than before plasma treatment. The contact angle of the thin films indicates that the composite samples become hydrophobic after plasma processing.