A process for the in-flight surface treatment of powders using a Dielectric Barrier Discharge Torch operating at atmospheric pressures or soft vacuum conditions is described herein. The process comprising feeding a powder material into the Dielectric Barrier Discharge Torch yielding powder particles exhibiting a reduced powder agglomeration feature; in-flight modifying the surface properties of the particles; and collecting coated powder particles. An apparatus for surface treating micro- and nanoparticles comprising a Dielectric Barrier Discharge Torch operating at atmospheric pressure or soft vacuum conditions is also described herein.