Electrostatic charging is an important, yet underappreciated, phenomenon associated with
handling and processing of powders. The ambiguous character of the process of charge
generation as well as the complex nature of solid surfaces make powder electrostatics unclear
and hard to comprehend or explain. The work carried out in this thesis aimed to provide a
detailed investigation on the impact of surface characteristics of powders on their
electrostatic behaviour. Here, the experimental design was intended to evaluate the effect of a
single parameter at a time, independently of other variables, in order to establish direct
correlations between the properties studied. This approach aims to understand why powders
exhibit different electrostatic behaviour and how this behaviour changes upon altering
material properties. In this work, the influence of surface chemistry on the electrostatic
performance has been determined explicitly for the first time for a number of surface
chemical groups. The material’s electrostatic behaviour was linked to the surface
hydrophobicity resulting from different groups being exposed. Furthermore, the impact of
changing humidity on the charge accumulation and dissipation was investigated and
concluded to be surface chemistry dependant. This concept was related to the crystal habit
and surface energy for mannitol crystals showing how changes in the crystal shape can
impact the powder electrostatics. The effect of the material’s internal structure was
investigated for amorphous and crystalline lactose and demonstrated that disordered
structures significantly decrease charge dissipation kinetics and lead to greater charge being
accumulated. The effect of water present in the amorphous/ crystalline phases was also
anticipated and determined to be a secondary factor guiding the behaviour. In this work, the
importance of surface coating occurring for the binary systems is emphasised and the
electrostatic behaviour of binary mixture is studied in detail. Finally, the impact of mixture
homogeneity on the electrostatic response was evaluated.