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Dielectric barrier discharges provide a simple technology to establish non-equilibrium plasma conditions in atmospheric-pressure gases and avoid vacuum conditions. Previously, we demonstrated that an Atmospheric Pressure Dielectric Barrier Glow Discharge (APDBGD) plasma can be effectively used for surface functionalization of nanoparticles, specifically nanodiamonds of detonation origin. An atmospheric pressure plasma allows one to perform nanoparticle functionalization of gram quantities of material within minutes. For nanodiamond fluorination experiments using CF4 as a feed gas, the XPS analysis confirmed a fluorine concentration of up to ~4.5at% of the nanodiamond particles surface. In the current paper, we extend the experiments using atmospheric pressure plasma to the surface functionalization of nano-crystalline diamond films, particularly fluorination, amination and ozonation of the surface. Functionalization of nano-crystalline diamond films would enable a variety of applications in engineering and biological sciences. For example, the hydrophobicity of nanodiamond films can be significantly alternated fluorine functionalization; fluorine on the surface can serve as a means for further chemical substitution reactions so that other more complex functional groups can be bond to the film surface such as amino acids, oligonucleotides, peptides, etc. facilitating the material applications in biosensors. Following plasma fluorination of nanodiamond films, XPS analysis revealed a high concentration of F on the diamond surface for films, nearly 50 at%. FTIR analysis revealed the presence F-bands related to CF3 (CF2) stretching vibrations and symmetric and asymmetric CF2 vibrations. Atmospheric plasma treatment in oxygen reduces the surface hydrogen termination and increase the termination with O and OH radicals. The treatment of the films with an ammonia discharge will be also reported. It was concluded that atmospheric pressure dielectric barrier glow discharge is a highly effective means to rapidly fluorinate, oxidize and aminate diamond surfaces. |