Control Over The Wettability Of Amorphous Carbon Films

The wettability of solid surfaces is a very important property, which is governed by both the chemical composition and the geometrical microstructure of the surface. Special and easily controllable wettability of solid has attracted much interest because it will bring great convenience on our daily life as well as in many industrial and agricultural processes, for example, super-hydrophobic surfaces (water contact angle (CA) larger than 150o) have or will play a important role in prevention of adhesion of snow to antennas and windows, self-cleaning traffic indicators, cell motility. As an environmentally benign and economically viable optoelectronic device material, amorphous carbon (a-C) films are of interests in various applications. Combined with special wettability properties, a-C films may have greater potential applications.In present thesis, a series of a-C films were prepared by magnetron sputtering technique on substrates as Si(100) and glass, and the deposited processes were controlled to adjust the morphology of the surfaces of a-C films. To further obtain the desired wettability, surface chemistry compound of the lotus-like surfaces were plasma modified by optimized processes.The main research progresses of this thesis are shown as follow:1. The a-C films with notably different surface micro-morphology were successfully fabricated by adjusting the sputtering process. There features change from smooth to a fractal-like structure with abounding holes and complicated gofers. Interestingly the complicated surface is much like the microstructure of nature lotus leaf, which has never reported in a-C films; Via CA tests on the a-C films with different surface features indicated that the wettability of a-C films can be controlled in large scale, ranging from very hydrophilicity (40o) to super-hydrophobicity (152o) by only adjusting the surface morphology;2. The a-C films were quantitatively analyzed by Boxing Dimension method. It indicates that with the fractal dimension increase, such surface of a-C film has more complicated microstructure, more and finer nanostructured grooves, so that it is able...