Jai Il Park
University of Toronto
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Publication
Featured researches published by Jai Il Park.
ACS Nano | 2010
Jai Il Park; Dinesh Jagadeesan; Ross Williams; Wendy Oakden; Siyon Chung; Greg J. Stanisz; Eugenia Kumacheva
We report a single-step approach to producing small and stable bubbles functionalized with nanoparticles. The strategy includes the following events occurring in sequence: (i) a microfluidic generation of bubbles from a mixture of CO(2) and a minute amount of gases with low solubility in water, in an aqueous solution of a protein, a polysaccharide, and anionic nanoparticles; (ii) rapid dissolution of CO(2) leading to the shrinkage of bubbles and an increase in acidity of the medium in the vicinity of the bubbles; and (iii) co-deposition of the biopolymers and nanoparticles at the bubble-liquid interface. The proposed approach yielded microbubbles with a narrow size distribution, long-term stability, and multiple functions originating from the attachment of metal oxide, metal, or semiconductor nanoparticles onto the bubble surface. We show the potential applications of these bubbles in ultrasound and magnetic resonance imaging.
Angewandte Chemie | 2009
Jai Il Park; Zhihong Nie; Alexander Kumachev; Ahmed I. Abdelrahman; Bernard P. Binks; Howard A. Stone; Eugenia Kumacheva
Bubbling up: Dissolution of CO(2) bubbles in a suspension of colloidal particles chemically induces the assembly of particles on the surface of shrunken bubbles, and thus yields rapid continuous formation of a colloidal armor. This approach maintains the high colloidal stability of particles in bulk, has increased productivity, and allows the formation of bubbles with precisely controlled dimensions.
Journal of the American Chemical Society | 2008
Zhihong Nie; Jai Il Park; Wei Li; Stefan Antonius Franciscus Bon; Eugenia Kumacheva
We report a versatile “inside-out” microfluidic approach to producing monodisperse particle-stabilized emulsions, as well as supracolloidal polymer microspheres. This approach addresses the challenges faced in conventional strategies for the preparation of Pickering emulsions, that is, an insufficient control of droplet dimensions and an excess of particles in the continuous media. The proposed method minimizes waste of particles, due to their introduction in the droplet phase, rather than in the continuous medium; allows control over the coverage of droplets with particles by manipulating the concentration of particles or the flow rates of the liquids; and provides a route for an easier analysis of the dynamics of formation and buckling of Pickering emulsions.
Macromolecular Rapid Communications | 2009
Jai Il Park; Ethan Tumarkin; Eugenia Kumacheva
A microfluidic route to producing small (<10 µm) bubbles with a narrow size distribution and long-time (at least, up to one month) stability is reported. The bubbles are encapsulated with a protein-polysaccharide shell. The strategy includes the following events, occurring in sequence: (i) a microfluidic generation of bubbles from a mixture of CO(2) and a minute amount of gases with low solubility in water, in an aqueous solution of lysozyme and sodium alginate; (ii) the dissolution of CO(2) leading to the shrinkage of bubbles and a local increase in acidity of the medium; (iii) the deposition of lysozyme at the gas-water interface triggered by the local decrease in pH; (iv) the deposition of alginate onto the lysozyme shell, due to the electrostatically driven complexation of alginate with lysozyme.
Soft Matter | 2010
Jai Il Park; Zhihong Nie; Alexander Kumachev; Eugenia Kumacheva
We report a new microfluidic strategy for the generation of small (<10 µm) microbubbles with a narrow size distribution. Our approach has the following features: (i) the generation of bubbles from gaseous CO2 and (ii) the controllable dissolution of these bubbles until they reach a desired size. We examine the role of various factors on the formation and the extent of bubble dissolution and show that the final dimensions of bubbles are determined by the flow rate of the continuous aqueous phase and the acid–base equilibria established within the microchannels.
Chemical Communications | 2011
Ethan Tumarkin; Jai Il Park; Zhihong Nie; Eugenia Kumacheva
This communication describes a novel strategy for the continuous microfluidic generation of highly monodispersed particle-coated microbubbles using temperature-dependent dissolution of carbon dioxide.
Annual Review of Materials Research | 2010
Jai Il Park; Amir Saffari; Sandeep Kumar; Axel Günther; Eugenia Kumacheva
Journal of Physical Chemistry C | 2012
Anna Lee; Aftab Ahmed; Diego P. dos Santos; Neil Coombs; Jai Il Park; Reuven Gordon; Alexandre G. Brolo; Eugenia Kumacheva
Angewandte Chemie | 2011
Nana Zhao; Jemma Vickery; Gerald Guerin; Jai Il Park; Mitchell A. Winnik; Eugenia Kumacheva
Macromolecules | 2009
Stanislav Dubinsky; Jai Il Park; Ilya Gourevich; Carol Chan; Martin Deetz; Eugenia Kumacheva