Fabrication of chitosan particles through a coaxial nozzle under pressurized carbon dioxide

Abstract

The generation of chitosan particles through supercritical carbon dioxide (SCCO2) antisolvent process was studied. The experiments were carried out at temperatures of 60–100°C and pressures of 15–25 MPa with a 15 ml min−1 CO2 flow rate. As a feed solution, chitosan powder was dissolved in acetic acid:water:ethanol. Scanning electron microscopy (SEM) observations described that the precipitated chitosan products have irregular morphologies with the spherical, the spherical with fiber‐like, and the fiber‐like free‐spherical particles. Interestingly, hollow‐core chitosan particles generated when SCCO2 antisolvent treatments were performed at a temperature of 60°C and pressures of 20–25 MPa. The Fourier transform infrared spectroscopy (FT‐IR) spectra indicated that the structural properties of chitosan did not shift after the SCCO2 antisolvent treatment. The results exhibited that this SCCO2 antisolvent technique is likely to be fruitful for the generation of biopolymer particles with hollow‐core structures.