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The relation between the cellulose nanocrystals (CNC) dynamic properties and the centrifugation G force applied on their purification process was investigated using the depolarized dynamic light scattering technic. Samples containing CNC were prepared using sulfuric acid hydrolysis and centrifugated on the following G forces: 1840, 4140, 7370, 11510 e 16580. The translational and rotational diffusion coefficients were determined for the different samples, from these values, the CNC widths (d) and lengths (L) were calculated. The values for the d and L lied from 213 ± 10 nm to 294 ± 14 nm and 4,4 ± 1,2 nm to 9,5 ± 2,0nm, respectively. The results agree with the the literature, confirming the applicability of the technic on the study of NCC dynamic properties in aqueous suspensions. There was no significant variation on the values of L by the increment on the G force within the studied interval. On the other hand, d reduced with the G force increase for values above 7370.

This research uses a computational fluid dynamic model to simulate motion and deformation of a dielectric drop in electrolyte solution in a microchannel. Wall charge density, the Debye-Hückel parameter and the Weber number are varied for uncharged, positively and negatively charged drop interfaces. Drop flow and deformation were analysed and the effects of charge distribution, electric field and permittivity jump were discussed. For a positively charged channel wall, negatively charged drops moved faster and positively charged drops moved slower than an uncharged drop. This effect increased for a higher We. Vortex flow was observed inside the drop. For a low surface tension, the drops were elongated due to electric forces acting on its surface with the charged drops deforming more than the uncharged one. When the permittivity component of the force was removed, the drop had a horizontal deformation that was sufficiently high to cause the negatively charged drop to break up.