Effect of initial concentration of chitosan on the particle size of chitosan nanoparticle

Various applications of chitosan lead to the growing interest of researchers to synthesise chitosan nanoparticles (CNP) which exhibit enhanced properties. However, it is very challenging to synthesise CNP due to the many parameters involved in the synthesis process which can affect the size of CNP. This work aims to synthesise CNP and investigate the effect of initial concentration of chitosan on the particle size of CNP. CNP was produced via ionic gelation process with varying initial concentration of chitosan (0.3, 0.6, 0.9, 1.2, 1.5, 1.8, and 2.1% w/v). Fourier transmission infrared (FTIR) analysis revealed the peak of amide shifted from 1629 cm-1 to 1635 cm-1, which confirmed the formation of CNP. Energy dispersive X-ray (EDX) elemental analysis revealed the presence of phosphorus in CNP. The particle sizes of CNP were measured using dynamic light scattering (DLS) and transmission electron microscopy (TEM). It was found that the average particle size of CNP increased from 46.7 nm to 225.33 nm with the increase in initial concentration of chitosan from 0.3 to 2.1% w/v due to the agglomeration of CNP, as proven from the TEM images.