Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/25/2015
Publication Date: 5/20/2015
Citation: Fanta, G.F., Kenar, J.A., Felker, F.C. 2015. Nanoparticle formation from amylose-fatty acid inclusion complexes prepared by steam jet cooking. Industrial Crops and Products. 74:36-44.
Interpretive Summary: Nanoparticles of starch that are extremely small, and can be seen only under high magnification with an electron microscope, are useful for a number of end-use applications, such as reinforcing agents for improving the strength of biodegradable plastics. Although many different methods have been reported for producing these starch-based nanoparticles, these published methods require lengthy and complex preparation procedures and yield only small quantities of the desired materials. In this study, we have used high pressure steam to prepare mixtures of cornstarch and non-toxic oleic acid, and have determined that these starch-oleic acid complexes precipitate from solution as nanometer-size particles when the hot dispersions are rapidly stirred and cooled. The smallest particles were observed with the most rapid rate of cooling and with the lowest concentration of jet cooked starch. Smaller particles had a greater tendency to aggregate. Since cooking with high pressure steam is a well-known, scalable process that is commonly used in the starch industry, starch nanoparticles can now be prepared in quantities sufficient to determine their properties and commercial applications. Consumers will benefit from this technology which improves the properties of biodegradable plastic products.
Technical Abstract: Starch-based nanoparticles are of increasing interest for use as biobased fillers in polymer composites. Many different methods have been reported for producing these nanoparticles, many requiring lengthy or complicated procedures. The purpose of this study was to determine whether the previously reported formation of spherulites by cooling jet cooked cornstarch dispersions combined with various ligands to form inclusion complexes could be adapted for nanoparticle synthesis. High-amylose cornstarch combined with oleic acid was jet cooked and then cooled at different rates ranging from 110 minutes to 10 seconds. Dynamic light scattering and SEM analysis revealed that nanoparticles with diameters from 63-375 nm were obtained, and X-ray diffraction showed that the nanoparticles were comprised of V6 amylose complexes. Cooling rate and starch concentration affected the yield and the tendency of nanoparticles to aggregate. Large quantities of starch-based nanoparticles can be obtained using this scalable technique for further characterization and development of end-use applications.