Chitosan, a useful biopolymer, was obtained from pulverized shells of blue crabs via demineralization, deproteination and de-acetylation. The chitosan was converted to nanoparticles using sodium tripolyphosphate (TPP). The FTIR spectrum of chitosan nanoparticles showed various functional groups, such as hydroxyl, carbonyl, and amine among others, as expected in chitosan. The SEM analysis revealed clusters of crystals at the surfaces, while TEM showed a very smooth and fine surface morphology. The particle size was estimated at < 200nm. The XRD spectrum showed shifting of the 2Ɵ peaks angles 10 and 20o for normal chitosan to 17 and 25o for the chitosan nanoparticles. The TGA and its derivative (DTGA) showed that the biopolymer was thermally stable.
