Synthesis and characterization of starch - based nanoparticles from native tapioca and corn starches

Tapioca and corn starch nanoparticle were prepared based on the water-in-oil emulsion technique and using ECH and TSTP as cross-linking agents. The effect of various processing parameters which include surfactant concentrations, cross-linker to starch molar ratio, type of cross-linker, organic to aqueous phase ratio and emulsifying stirring speed on the size of starch particles were investigated. Besides, cross-linked tapioca and corn starch samples were characterized using Scanning Electron Microscopy (SEM), Fourier Transformed Infrared (FTUR) Spectroscopy and Total Organic Carbon Analyzer, Rapid Visco Analyzer and Equilibrium Swelling Study. SEM analyses indicated that well-dispersed cross-linked tapioca and corn starch samples were consist of particles with size less than 1µm. However these cross-linked starch samples were observed to have high tendency to form aggregates and gels which could not be dispersed easily in aqueous media. The incomplete dispersed nanoparticulate samples coupled with limited SEM resolution have resulted in the quantitative determination of particle size distribution impossible. Nevertheless several of the welldispersed and less-dispersed nanoparticulate cross-linked starch samples have provided ample evidences that nano-sized starch particles were formed from both native tapioca and corn starches under various synthesis parameters used in this study. Results obtained from FTIR, TOC and ESD showed that all cross-linked starch samples have very similar physical and chemical characteristics but are distinctively different from their respective native starches