HYDROXYLAMINE SEEDING OF COLLOIDAL METAL NANOPARTICLES

摘要

Methods for preparing colloidal metal nanoparticles, in which a solution of reductant is added to a boiling solution of a source of metal ion coincidentally with seed colloids are described, including a method using colloidal gold nanoparticle seeds, a gold ion source (HAuCl4), and sodium citrate (reductant). Methods for preparing colloidal metal nanoparticles, in which seed colloids are added to a solution of reductant mixed with a solution containing a source of metal ions are also described, including a method in which the seeds are colloidal gold nanoparticles, the source of gold ions is HAuCl4, and the reductant is NH2OH. Methods for preparing colloidal metal nanoparticles, in which the seed colloids are the result of the application of the previous methods, and the source of metal ions and the reductant are added to the seed colloids in an iterative fashion, are also described. The colloidal metal nanoparticles that are the product of the application of the above methods are also described. Certain colloidal metal nanoparticles have a major axis standard deviation of about 14 % or less, a minor axis standard deviation of about 14 % or less, and an ellipticity < 1.5. Other colloidal metal nanoparticles have major axis standard deviation of about 29 % or less, a minor axis standard deviation of about 20 % or less, and an ellipticity > 1.5.