Bandulasena et al. Droplet-based microfluidic method for robust preparation of gold nanoparticles in axisymmetric flow.pdf (2.66 MB)

Droplet-based microfluidic method for robust preparation of gold nanoparticles in axisymmetric flow focusing device

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journal contribution
posted on 15.10.2018, 15:17 by Monalie Bandulasena, Goran Vladisavljevic, Brahim Benyahia
A novel microfluidic mixing strategy was developed and used to prepare polyvinylpyrrolidone (PVP) capped gold nanoparticles (AuNPs). In this process, 1 mM tetrachloroauric acid (HAuCl4) stream containing 1% (w/v) PVP was injected through the inner capillary tube and mixed with 20 mM L-ascorbic acid solution delivered co-currently through the outer coaxial capillary. The reaction mixture was hydrodynamically flow focused by the environmentally friendly oil Miglyol 840 delivered from the opposite side of the outer capillary, which resulted in the generation of reaction droplets in a tapered collection tube. The reactants were rapidly mixed within droplets by internal circulating flows induced by hydrodynamic interactions of fluids inside the droplets with the carrier oil. The size of the prepared AuNPs was measured by both dynamic light scattering and transmission electron microscopy and was found to decrease with decreasing the droplet size and increasing the difference in velocity between the two reactant streams, which improved mixing efficiency within droplets. The smallest nanoparticles were obtained when the outlet section of the injection tube was positioned at the entry section of the collection tube due to the highest shear at the liquid interface. The carrier oil formed a hydrophobic barrier between the droplets and the reactor walls preventing deposition of the synthesised particles. As a result, the size of the AuNPs was smaller than in the co-flow mixer operated with two continuous reactant streams.

Funding

The microfluidic rig used in the project was purchased from the grant EP/J020184/1, funded by EPSRC, UK.

History

School

  • Aeronautical, Automotive, Chemical and Materials Engineering

Department

  • Chemical Engineering

Published in

Chemical Engineering Science

Volume

195

Pages

657-664

Citation

BANDULASENA, M.V., VLADISAVLJEVIC, G.T. and BENYAHIA, B., 2019. Droplet-based microfluidic method for robust preparation of gold nanoparticles in axisymmetric flow focusing device. Chemical Engineering Science, 195, pp. 657-664.

Publisher

© Elsevier

Version

AM (Accepted Manuscript)

Publisher statement

This paper was accepted for publication in the journal Chemical Engineering Science and the definitive published version is available at https://doi.org/10.1016/j.ces.2018.10.010

Acceptance date

07/10/2018

Publication date

2018-10-09

Copyright date

2019

ISSN

0009-2509

Language

en

Exports