Mechanisms of electrostatic charge reduction of granular media with additives on different surfaces

Differential Electrostatic Interactions between Granular Species in a Simple Hopper Chute Geometry

“…Work functions of the different materials involved were determined using molecular mechanics software, MOPAC 2009, starting from molecular structures at equilibrium geometry generated with AVOGADRO 1.0.3 with Restricted Hartree Fock (RHF) PM3 methodology, as outlined by Mazumder et al [18] Table 3 enlists the properties of different materials used in the study. The authors acknowledge that the value of PVC is over predicted, most likely due to a computational limitation in capturing the chain length as discussed previously [17]. However, our assessment should not be qualitatively affected as PVC is known to have the highest work function amongst all materials assessed in this study.…”

“…For charge reduction studies, the additives and particles were layered over each other. Homogenous discharge of material from such a layered mixture has been documented previously [17]. The previous work dealt with some commonly found second components but the current article investigates some pharmaceutical excipients as the second component.…”

“…The broad methodology and experimental set up is adopted from Sarkar et al [17]. The experimental assembly is shown in Figure 1.…”

“…All the statistical tests were done in MS EXCEL. The charge reduction studies were done under the previously identified optimum conditions [17], i.e. 30°C chute angle and a mass loading of 30 g of 1 mm size primary particles.…”

Electrostatics effects in granular materials

“…The purpose of the study is to identify the factors influencing the tribocharging of primary glass and lactose spheres on different surfaces, and determine conditions corresponding to least statistical variability in generation of such charges in a simple hopper-chute set up (6). The optimal conditions thus determined are then used to determine influence of different additives with respect to their chemical nature and concentration.…”