(8d) Mechanism Study of Starch Nanoparticle Formation
Preparation and application of biomaterial based nanoparticles have been attracting more research interests. Nano-sized starch particles can be prepared by using different approaches, such as acid hydrolysis, inverse microemulsion polymerization, and mechanical treatment. Reactive extrusion method is a simple, efficient, and environmental friendly method for nanostarch preparation. In this study, the mechanism of starch nanoparticle formation during extrusion was investigated. The effects of extrusion conditions, including temperature (50~100oC), screw speed, residence time, starch moisture content and crosslinker addition, on particle size were studied. The results indicate that after extrusion at 100oC, the starch particles with a size of 320~400 nm were obtained. With the addition of appropriate crosslinkers, the starch particle size could be further reduced to around160 nm. The morphology, crystalline property, thermal stability and rheology properties of starch nano particles were also characterized.