Ripening and focusing of aggregate size distributions with overall volume growth

Frontiers in Physics

Vollmer, Jü¹  Papke, Ariane²  Rohloff, Martin³  rgen⁴ 

[1] Department of Dynamics of Complex Fluids, Max Planck Institute for Dynamics and Self-Organization (MPI DS), GöInstitute for Nonlinear Dynamics, Faculty of Physics, Georg August University Göttingen, Göttingen, Germany

关键词: ostwald ripening;    size focusing;    Lifshitz-Slyozov-Wagner theory;    Nanoparticle Synthesis;    rain drop size distribution;    Phase Separation;    continuous driving;    asymptotic solutions of nonlinear differential equations;    Bifurcations;   

DOI  :  10.3389/fphy.2014.00018

学科分类：物理（综合）

来源: Frontiers

【 摘 要 】

We explore the evolution of the aggregate size distribution in systems where aggregates grow by diffusive accretion of mass. Supersaturation is controlled in such a way that the overall aggregate volume grows linearly in time. Classical Ostwald ripening, which is recovered in the limit of vanishing overall growth, constitutes an unstable solution of the dynamics. In the presence of overall growth evaporation of aggregates always drives the dynamics into a new, qualitatively different growth regime where ripening ceases, and growth proceeds at a constant number density of aggregates. We provide a comprehensive description of the evolution of the aggregate size distribution in the constant density regime: the size distribution does not approach a universal shape, and even for moderate overall growth rates the standard deviation of the aggregate radius decays monotonically. The implications of this theory for the focusing of aggregate size distributions are discussed for a range of different settings including the growth of tiny rain droplets in clouds, as long as they do not yet feel gravity, and the synthesis of nano-particles and quantum dots.

【 授权许可】

CC BY