Applying the Macroscopic Kinetic Approach to Plasma Polymerization to the Plasma Surface Modification of Micropowders: Attempt of Correlating Powder Flowability and Plasma Process Parameters

The flowability of micropowders can be improved by depositing a non-continuous coating on the micropowder surface, which reduces the interparticle van der Waals forces causing cohesion of the native powder. Such a coating can be achieved via a plasma enhanced chemical vapor deposition in a tubular, inductively-coupled RF glow-discharge-plasma reactor fed by plasma-polymerizable gases. Here we systematically study the influence of user-set plasma parameters of feed gas flow rate and plasma power on the resulting powder flowability. We find a quasi-Arrhenius relation between flowability factor and energy delivered per mass of monomer W/FM. These findings demonstrate that flowability measurements can be used to study the plasma polymerization processes and as a metric to assess surface coatings of powders that are otherwise difficult to characterize by standard metrologies.