A Theoretical Model for Digestive Ripening
Recently, gram quantities of monodisperse gold or silver nanoparticles were reported to be produced through a digestive ripening process, in which colloidal particles of size 2 to 40 nm are transformed to nearly monodisperse particles of 4 ~ 5 nm diameter. Digestive ripening, an example for an inverse Ostwald ripening process, is a puzzling phenomenon since it appears to go against the usual capillary effect, i.e., reduction of interfacial free energy. A theoretical model is presented, which accounts for the monodisperse state of such nanoparticles by considering the effect of charges on the particles and thus electrostatic energy during particle size evolution.
Young Won Chang, Nack J. Kim and Chong Soo Lee
D. K. Lee et al., "A Theoretical Model for Digestive Ripening", Materials Science Forum, Vols. 561-565, pp. 2279-2282, 2007