Houk Levi R, Challa Sivakumar R, Grayson Benjamin, Fanson Paul, Datye Abhaya K
Center for Microengineered Materials, Department of Chemical & Nuclear Engineering, University of New Mexico, Albuquerque, NM 87131-0001, USA.
Langmuir. 2009 Oct 6;25(19):11225-7. doi: 10.1021/la902263s.
An improved, exact analysis of surface Ostwald ripening of a collection of nanoparticles is presented in an effort to redefine the critical radius involved in the kinetic models of ripening. In a collection of supported particles of different sizes, the critical radius is the size of the particle that is in equilibrium with the surrounding adatom concentration. Such a particle neither grows nor shrinks due to Ostwald ripening, whereas larger particles grow and smaller particles shrink. We show that previous definitions of critical radius are applicable only for limiting regimes where the Kelvin equation has been linearized. We propose a more universally applicable definition of critical radius that satisfies the constraints of mass balance.
本文提出了一种改进的、精确的纳米颗粒集合表面奥斯特瓦尔德熟化分析方法，旨在重新定义熟化动力学模型中涉及的临界半径。在不同尺寸的负载颗粒集合中，临界半径是与周围吸附原子浓度处于平衡状态的颗粒尺寸。由于奥斯特瓦尔德熟化，这样的颗粒既不生长也不收缩，而较大的颗粒生长，较小的颗粒收缩。我们表明，先前对临界半径的定义仅适用于开尔文方程已线性化的极限情况。我们提出了一种更普遍适用的临界半径定义，该定义满足质量平衡的约束条件。
