Functionalization of viscose fabric was demonstrated using helium/dodecyl acrylate (He/DA) plasma operated under pulse conditions at atmospheric pressure. The effects of power densities and pulse durations on total reaction time and consumed energy were investigated. The use of high power density modulated at low duty cycles (i.e. low pulse durations) resulted in rapid and effective functionalization with low energy consumption. In comparison to reactions carried out at low power densities, reactions at high power modulated at low duty cycles utilized only 117% more energy while reducing the reaction time to 1/8th to achieve similar levels of functionalization. The hydrophobically modified viscose fabric was durable to solvent washings and exhibited drop absorbency time of > 60 min and water contact angle > 150 degrees. FESEM analysis revealed that plasma modulated at low duty cycles (similar to 0.1) led to uniform deposition of polymerized material and minimal fragmentation of monomer molecules. Surface chemistry of treated fabrics was further elucidated using X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance spectroscopy (NMR) and time of flight-secondary ion mass spectroscopy (ToF-SIMS).