Triboelectrification: A review of experimental and mechanistic modeling approaches with a special focus on pharmaceutical powders

The continuous relative motion of particles against solid surfaces in pharmaceutical manufacturing triggers multiple physio-chemical alterations generating contact charging or triboelectrification. Charged particles in manufacturing processes can actuate multiple impediments including agglomeration, segregation during flow or adhesion to process equipment. Generation of excess charge might lead to electrostatic discharges inducing severe imperilments of fire and explosions. Despite its prevalence, the electrostatic charging process is not fully understood, owing to the diverse physical, chemical and environmental factors that can affect the phenomenon. In the course of this review, some of the basic concepts involved in charge transfer have been briefly discussed highlighting the different experimental approaches employed in measuring electrostatic charges and summarizing the constituent factors responsible. Pertinent numerical models have been further conferred to analyze the different hypotheses of particle charging. (C) 2016 Elsevier B.V. All rights reserved.