On-chip controlled synthesis of polycaprolactone nanoparticles using continuous-flow microfluidic devices

This systematic investigation assessed the potential applications of microfluidic devices in producing a uniform size distribution of polycaprolactone (PCL) nanoparticles by applying the liquid non-solvent precipitation process. Five arrangements of microfluidic devices are fabricated with different designs. The effects of different operational and geometrical factors such as flow rate ratio (FRR), total flow rate (TFR), mixing channel width, mixing channel length, and confluence angles of the inlet channels are investigated on the size, polydispersity index (PDI), and the size distribution of PCL particles. Further, a study was performed to enhance the production throughput of PCL nanoparticles. The mean size of nanoparticles is precisely controlled within the range of 40–370 nm with PDI values of 0.2–0.37. According to the results, the optimal conditions for rapid production of nanoparticles with a size smaller than 200 nm and PDI ≤ 0.31 are obtained at FRR of 8, TFR of 70 ml h−1, channel width of 200 μm, channel length of 20 mm, and the confluence angle of 60o. Furthermore, the microfluidic device with a wider channel width of 600 μm provided a higher productivity rate of the PCL nanoparticles with a similar size and lower PDI than those obtained by other widths.