Effect of operating conditions on size and morphology of amylose nanoparticles prepared by precipitation

Nano-sized amylose particles were prepared by precipitating amylose solution (using DMSO/water mixture as solvent) with absolute ethanol. Effects of operating conditions, including temperature and solvent composition for preparing amylose solution, amylose concentration, ethanol amount used for precipitating, and mode of agitation during precipitation, on size of amylose nanoparticles were investigated. The results of dynamic light scattering (DLS) measurement and scanning electron microscopy (SEM) observation showed that all the above operating conditions have great impact on size of regenerated amylose particles. By increasing amylose solution preparation temperature and DMSO/water volume ratio in solvent, regenerated amylose particles can be tuned from micro to nanometer. Through adjusting operating parameters, such as increasing the amount of ethanol used for precipitating, decreasing amylose solution concentration and using ultrasonic agitating during precipitation, amylose nanoparticles could be further reduced to 160nm.