Al nuumani et al. Highly porous magnetic Janus microparticles with asymmetric surface topology.pdf (1.74 MB)
Download fileHighly porous magnetic Janus microparticles with asymmetric surface topology
journal contribution
posted on 2020-10-05, 14:47 authored by Ruqaiya Alnuumani, SK Smoukov, Guido Bolognesi, Goran VladisavljevicGoran VladisavljevicMonodispersed magnetic Janus particles composed of a porous polystyrene portion
and a nonporous poly(vinyl acetate) portion with embedded oleic acid-coated magnetic
nanoparticles were generated using microfluidic emulsification followed by two distinct phase
separation events triggered by solvent evaporation. The template droplets were composed of 2
wt% polystyrene, 2 wt% poly(vinyl acetate) and 0.5-2 wt% n-heptane-based magnetic fluid
dissolved in dichloromethane (DCM). The porosity of polystyrene compartments was the result of
phase separation between a non-volatile non-solvent (n-heptane) and a volatile solvent (DCM)
within polystyrene-rich phase. The focused ion beam cross-sectioning and SEM imaging revealed
high surface porosity of polystyrene compartments with negligible porosity of poly(vinyl acetate)
parts, which can be exploited to increase the wettability contrast between the two polymers and
enhance bubble generation in bubble-driven micromotors. The porosity of the polystyrene portion
was controlled by varying the fraction of n-heptane in the dispersed phase. The particle
composition was confirmed by scanning electron microscopy-energy dispersive X-ray
spectroscopy, Fourier transform infrared spectroscopy, and differential scanning calorimetry. The
fabricated particles were successfully magnetised when subjected to an external magnetic field,
which led to their aggregation into regular 2D assemblies. The particle clusters composed of 2-4
individual particles could be rotated with a rotating magnetic field. Microfluidic generation of
highly porous Janus particles with compositional, topological, and magnetic asymmetry provides
a cost-effective, easy-to-implement yet highly robust and versatile strategy for the manufacturing
of multifunctional smart particles.
Funding
Microfluidic methods for production of core/shell capsules using natural and synthetic biodegradable polymers EP/HO29923/1
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Chemical Engineering
Published in
Langmuir: the ACS journal of surfaces and colloidsVolume
36Issue
42Pages
12702–12711Publisher
American Chemical SocietyVersion
- AM (Accepted Manuscript)
Rights holder
© American Chemical SocietyPublisher statement
This document is the Accepted Manuscript version of a Published Work that appeared in final form in Langmuir: the ACS journal of surfaces and colloids, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.langmuir.0c02315Acceptance date
2020-10-03Publication date
2020-10-14Copyright date
2020ISSN
0743-7463eISSN
1520-5827Publisher version
Language
- en