Abstract
We present an experimental study of selfassembled polymeric nanoparticles in the process of flash nanoprecipitation using a multi-inlet vortex mixer (MIVM). β-Carotene and polyethyleneimine (PEI) are used as a model drug and a macromolecule, respectively, and encapsulated in diblock copolymers. Flow patterns in the MIVM are microscopically visualized by mixing iron nitrate (Fe(NO3)3) and potassium thiocyanate (KSCN) to precipitate Fe(SCN)(3-x)+x. Effects of physical parameters, including Reynolds number, supersaturation rate, interaction force, and drug-loading rate, on size distribution of the nanoparticle suspensions are investigated. It is critical for the nanoprecipitation process to have a short mixing time, so that the solvent replacement starts homogeneously in the reactor. The properties of the nanoparticles depend on the competitive kinetics of polymer aggregation and organic solute nucleation and growth. We report the existence of a threshold Reynolds number over which nanoparticle sizes become independent of mixing. A similar value of the threshold Reynolds number is confirmed by independent measurements of particle size, flowpattern visualization, and our previous numerical simulation along with experimental study of competitive reactions in the MIVM.
Original language | English (US) |
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Pages (from-to) | 4109-4120 |
Number of pages | 12 |
Journal | Journal of Nanoparticle Research |
Volume | 13 |
Issue number | 9 |
DOIs | |
State | Published - Sep 2011 |
All Science Journal Classification (ASJC) codes
- Bioengineering
- Chemistry(all)
- Atomic and Molecular Physics, and Optics
- Modeling and Simulation
- Materials Science(all)
- Condensed Matter Physics
Keywords
- Colloids
- Competitive kinetics
- Micellization
- Micromixing
- Nucleation and growth
- Reynolds number
- Supersaturation
- Synthesis