A comprehensive mathematical model for nanofibre formation in centrifugal spinning methods
Motivated by our experimental observations of nanofibre formation via the centrifugal spinning process, we develop a string model to study the behaviours of a Newtonian, viscous curved jet, in a non-orthogonal curvilinear coordinate system including both air-drag effects and solvent evaporation for the first time. In centrifugal spinning a polymeric solution emerges from the nozzle of a spinneret rotating at high speeds around its axis of symmetry and thins as it moves away from the nozzle exit until it finally lands on the collector. Except for the Newtonian fluid assumption, our model includes the key parameters of the curved jet flow, e.g. viscous, inertial, rotational, surface tension, gravitational, mass diffusion within the jet, mass diffusion into air and aerodynamic effects, via Rossby ( $Rb$ ), Reynolds ( $Re$ ), Weber ( $We$ ), Froude ( $Fr$ ), Péclet ( $Pe$ ), air Reynolds ( $Re^{\ast }$ ) and air Péclet ( $Pe^{\ast }$ ) numbers, and the collector radial position ( ${\mathcal{R}}$ ). Our results, including comparison to experiments, reveal that the aerodynamic effects must be considered to enable a correct prediction of the jet trajectory and radius. Decreasing $Rb$ not only renders the jet thinning much faster, but also forces more »
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Publication Date:
NSF-PAR ID:
10175504
Journal Name:
Journal of Fluid Mechanics
Volume:
892
ISSN:
0022-1120
National Science Foundation
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