The Synthesis and Assembly of Polymeric Microparticles Using Microfluidics

Abstract

The controlled synthesis of micrometer‐sized polymeric particles bearing features such as nonspherical shapes and spatially segregated chemical properties is becoming increasingly important. Such particles can enable fundamental studies on self‐assembly and suspension rheology, as well as be used in applications ranging from medical diagnostics to photonic devices. Microfluidics has recently emerged as a very promising route to the synthesis of such polymeric particles, providing fine control over particle shape, size, chemical anisotropy, porosity, and core/shell structure. This progress report summarizes microfluidic approaches to particle synthesis using both droplet‐ and flow‐lithography‐based methods, as well as particle assembly in microfluidic devices. The particles formed are classified according to their morphology, chemical anisotropy, and internal structure, and relevant examples are provided to illustrate each of these approaches. Emerging applications of the complex particles formed using these techniques and the outlook for such processes are discussed.

Porous polymer particles—A comprehensive guide to synthesis, characterization, functionalization and applications

“…A novel or improved technique [453][454][455] inheriting abilities of microfluidics but overcoming its problems such as tedious device preparation and scalability would be another renaissance for particle production. Finally, unique mechanical, packing and assembly properties of nonspherical particles are already drawing attention [6,85,161,[453][454][456][457][458][459][460][461][462][463][464][465][466][467][468] but the effect of porosity on such regular nonspherical particles is still waiting to be further exploited.…”

“…The closest review on this topic by Okay in 2000 [1] deals more with particle characteristics, explains the methods of production and characterization briefly and lacks discussion about applications. Although in literature there are several reviews for polymer particles (not specifically porous), the older ones [1][2][3] merely cover the conventional methods (suspension, emulsion, dispersion, precipitation, seeded) while the new ones [4][5][6] only focus on the new methods (membrane/microchannel emulsification and microfluidics). To the best of our knowledge, we gathered in this review for the first time all the manufacture methods, including some less known methods.…”

Fabrication, Assembly, and Application of Patchy Particles

“…Selective modification of a segment of a particle surface is directly feasible in the case of the PVD technique because of the inherent shadow effect. In addition to the conventional surface modification techniques, [62,63] more recently capillary flow techniques [13,15,[64][65][66][67] and colloidal assembly [68,69] methods have been explored for the fabrication of patchy particles and therefore will be included here.…”

High throughput generation and trapping of individual agarose microgel using microfluidic approach

“…By controlling the density of the polymer network, microgels can be formed with various morphologies, such as uniform, gradient or capsular type (Dendukuri and Doyle 2009). Due to the open network structure, polymer microgels have the ability of sequestering small molecules or nanoparticles and changing their dimensions under diversiform environmental stimuli [such as pH (Ko et al 2002), ionic strength (Tan and Takeuchi 2007), temperature (Kawaguchi and Suzuki 2005) or electric field (Chiou et al 2005)] accordingly.…”