Microwave mediated preparation of nanoparticles from wx corn starch employing nanoprecipitation

The influence of alkali concentration, temperature, concentration of urea and KSCN on the shapes and sizes of wx corn starch precipitates (isolated via nanoprecipitation) were studied. A strong correlation was found between the molecular and hydrodynamic characteristics, determined by using asymmetrical flow-field flow fractionation (AF4), and the resultant sizes of micro- and nanostructures of wx corn starch precipitates (SEM images). Treatment of wx corn in alkaline media at higher temperatures employing a dedicated microwave reactor resulted in the formation of submicron particles (SEM analysis). The apparent molecular characteristics of wx corn starch heated in 1M NaOH at various temperatures employing a microwave reactor, decreased with increasing temperature and with a corresponding decrease in particle sizes (SEM images of the precipitates). An expansion and decrease in the overall densities of the starch structures was observed for wx corn in 1M urea, 0.2M NaOH at 130 degrees C resulting in smaller particle sizes.