Wettability control of nano-columnar DLC thin films via Eb-irradiation

Abstract

Amorphous carbon (a-C:H/a-C) or Diamond-like carbon, have a very high potential diverse engineering application especially in protective coating which made it an ideal method to be manipulated in process parameters so to achieve the desired mechanical and functional properties; this correlates to the smoothness, atomic density, and the sp3 content. The nano-structure of this amorphous carbon is characterized by its disordered state of sp2 and sp3. The mechanical property would response to the sp2/sp3 matrix with the small hydrogen content which leads to the significant increases in hardness, tribological and also the wettability properties. This vague columnar structure of DLC is strictly modified to fine and self-organized structure, where high-density, graphitic inter-columnar structure is embedded into the low-density amorphous carbon phase as being confirmed through characterization, mechanical properties and response. This unique hybrid system in the a-C:H films would control the functionality of the final coating in customized way to suit multi-disciplinary engineering applications. This Nano-columnar a-C:H system. However, this hybrid system is still bound to the triangular diagram of sp2-sp3-H in the formation of a-C or a-C:H. This formed nano-columanar a-C:H films shows a unique nano-structure and its graphatized inter-columnar network with amorphous columns responsible the desired properties manipulation. In this paper, correlation between the degree of graphitization and wettability is established.