Advances in the Production of PBCA Microparticles Using a Micromixer with HH-Geometry in a Microfluidic System

Different reaction control methods for producing nano/microstructures of poly(butyl cyanoacrylate) (PBCA) have been studied, focusing on pH and monomer-to-initiator ratios. However, these methods often require multiple steps and reagents. In the synthesis of PBCA microparticles using three versions of micromixers designed with HH geometry and varying numbers of channels (4, 10, and 15), different synthesis formulations were investigated by varying monomer concentrations. PBCA microparticles synthesized with 19.2% (w/w) n-butyl cyanoacrylate (n-BCA) monomer, a residence time of 0.06 s, a flow rate of 78 mL·min−1, and a phase ratio of 45/55 (W/O), exhibited an average diameter of 642.2 nm as determined by dynamic light scattering (DLS) analysis. In contrast, PBCA microparticles synthesized with 5.0% (w/w) n-BCA monomer, the same residence time of 0.06 s, a flow rate of 39 mL·min−1, and a phase ratio of 20/80 (W/O), exhibited an average diameter of 74.73 µm according to laser diffraction particle size analysis. Polymer formation was confirmed by Fourier-transform infrared (FTIR) spectroscopy in both formulation and process conditions. These results indicate that the parameters for the production of microparticles with different monomer concentrations in the microfluidic system with HH geometry and 15 channels can be optimized for potential applications in cosmetics and pharmaceutical ingredients.