Microfluidic-based synthesis of non-spherical magnetic hydrogel microparticles

Abstract

Spherical and non-spherical magnetic hydrogel particles were synthesized in a microfluidic device containing an embedded UV light reflector. Monodisperse magnetic emulsion droplets were generated in a T-junction and allowed to relax into spheres, disks, and plugs in confining microchannel geometries. Particle morphology was locked-in via UV-initiated photopolymerization. The role of the reflector in the microchannel is to provide a uniform distribution of UV energy to the magnetic emulsion droplets and to increase the UV flux, which significantly improves UV polymerization conditions for microfluidic-based particle synthesis. Magnetic nanoparticles were uniformly encapsulated in the hydrogel, giving the microparticles superparamagnetic behavior. Additionally, the non-spherical particles show anisotropic responses under an applied external magnetic field.

Enhanced-throughput production of polymersomes using a parallelized capillary microfluidic device

“…For example, single-emulsion drops, prepared in such microfluidic devices, can be employed to make monodisperse spherical microparticles with optical, electrical, and magnetic functionalities (Kim et al 2008a(Kim et al , 2010Nie et al 2006;Nisisako et al 2006;Zhao et al 2008). In addition, nonspherical microparticles can also be prepared by deforming the drops or making pairs of drops (Dendukuri et al 2005;Hwang et al 2008;Kim et al 2011a;Nisisako and Torii 2007;Xu et al 2005). Moreover, microfluidic emulsification enables generation of doubleemulsion drops, or drops in drops, in an efficient way, which is otherwise difficult to achieve using bulk emulsification (Okushima et al 2004;Utada et al 2005).…”

Shape controllable microgel particles prepared by microfluidic combining external ionic crosslinking

“…[5][6][7][8][9][10][11][12][13][14] Non-spherical microgel, such as rod-like, wedge-like, and disk-like microgels, can also be prepared via well-designed microfluidic channels or mask-photopolymerization. [15][16][17][18][19][20][21][22][23] Nowadays, it still remains a challenge for preparing more complicated microgels with controllable shapes and built-in functionalities for novel applications, which mimic those of some living micro-creatures. Recently, Sarkar and his coworkers modeled the deformation of a viscoelastic drop falling through a Newtonian medium and pointed out that viscoelasticity can make an initially spherical drop deformed into an oblate shape with a dimple at the rear end.…”

Microfluidics-Nano-Integration for Synthesis and Sensing

“…Schematic diagram of the T-junction microfluidic channel with aluminium reflectors for spherical and non-spherical magnetic hydrogel synthesis: sphere, disk, and plug. Pm indicates the input pressure for the hydrogel precursors (dispersed phase) and Po the input pressure for the mineral oil (continuous phase) [49]. Figure 37.…”

“…Doyle et al [49] have synthesized magnetic hydrogel particles with different shapes (spheres, disks, and plugs) in a T-junction microfluidic device (Figures 36 and 37). Figure 36.…”