Laboratory scale systems for the plasma treatment and coating of particles

We here report two reactor designs for the efficient and uniform plasma treatment of particles: 1) retrofitting an existing plasma reactor with a loudspeaker for agitation (LPR) and 2) adapting a rotary evaporator by adding custom electrodes (RPR). Both designs offer versatility, low building cost, convenience of use, flexibility, facile vacuum sealing and achieve effective agitation and coating of particles. The latter was exemplified by plasma polymerizing perfluorooctane (PFO) onto micron-sized polystyrene particles. The coated particles were evaluated by XPS, ToF-SIMS and water contact angle measurement to compare and contrast the resulting PFO plasma coatings (PFOpp) between the two reactor designs. The highest fluorine to carbon ratio (1.85, Teflon=2) was achieved at a pressure of 100mTorr in the RPR. We report and compare two designs of plasma reactors for microparticles and nanoparticles. One design retrofits a loudspeaker for agitation of particles while the other system adapts a rotary evaporator for mixing particles. Both designs offer low build cost, convenience of use, and experimental flexibility. Particles are coated uniformly, using perflurooctane as a precursor, in both systems.