Synthesis and characterization of chitosan droplet particles by ionic gelation and phase coacervation

The present study focused on formation of chitosan (CS) droplets particles/microcapsules by ionic gelation method with sodium dodecylsulfate (SDS) for encapsulating linseed oil as active substance. Chitosan droplet particles with four alternate layers of CS and SDS were developed from oil in water emulsion using SDS as an anionic emulsifier. The process was optimized by zeta potential measurements to avoid overcharging of particles by excess addition of CS. The drying process promoted coalescence of CS droplet particles to form a functional coating and to protect the core substance against influence of environmental conditions. The functional coating formed by the particles was characterized by scanning electron microscopy, wetting measurements, and atomic force microscopy and surface roughness. Atomic force microscopy and surface roughness analyses indicated that smooth surface with more hydrophobic groups on the surface of functional coating was obtained after CS addition and it was due to film forming ability of CS chains in the system.