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Abstract Copper nanoparticles (CuNPs) embedded in polyvinylpyrrolidone (PVP) and polyethylene oxide (PEO) fiber‐matrices were prepared through centrifugal spinning of PVP/ethanol and PEO/aqueous solutions, respectively. The prime focus of the current study is to investigate the antibacterial activity of composite fibers againstEscherichia coli(E. coli) andBacillus cereus(B. cereus) bacteria. During the fiber formation, the centrifugal spinning parameters such as spinneret rotational speed, spinneret to collector distance, and relative humidity were carefully chosen to obtain long and continuous fibers. The structural and morphological analyses of both composite fibers were investigated using scanning electron microscopy, X‐ray diffraction, energy‐dispersive X‐ray spectroscopy, and thermogravimetric analysis. In the antibacterial test, PVP/Cu and PEO/Cu composite fibrous membranes exhibited inhibition efficiency of 99.98% and 99.99% againstE. coliandB. cereusbacteria, respectively. Basically, CuNPs were well embedded in the fibrous membrane at the nanoscale level, which facilitated the inhibition of bacterial functions through the inactivation of the chemical structure of the cells. Such an effective antibacterial agent obtained from forcespun composite fibers could be promising candidates for biomedical applications.
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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 the jet to wrap tighter around the rotation axis. Increasing $Re$ , $$Re^{\ast }$$ and $${\mathcal{R}}$$ leads to a longer jet. Decreasing $We$ causes the jet to wrap tighter around the spinneret but it shows trivial effects on the solvent evaporation. Changes in $Pe$ and $$Pe^{\ast }$$ do not significantly affect the jet trajectory. Finally, we propose simple relations to estimate the jet radius and the jet breakup length.
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- Award ID(s):
- 1707640
- PAR ID:
- 10175504
- Date Published:
- Journal Name:
- Journal of Fluid Mechanics
- Volume:
- 892
- ISSN:
- 0022-1120
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1017/jfm.2020.196
