On Ostwald’s supersaturation theory of rhythmic precipitation (Liesegang’s rings)
On Ostwald’s supersaturation theory of rhythmic precipitation (Liesegang’s rings)
复制标题
论奥斯特瓦尔德的节律性降水过饱和理论（利泽冈环）
DOI：
10.1063/1.448012
复制
发表时间：
1984
影响因子：
4.4
通讯作者：
D. Smith
中科院分区：
文献类型：
--
作者：
D. Smith
利泽冈环是溶液中两种成分相互扩散并反应形成不溶沉淀物时形成的细沉淀带。奥斯特瓦尔德的过饱和理论，以 Prager 和 Zeldovitch 等人给出的定量形式，正确地预测了某些系统中环形成过程的许多特征。不符合奥斯特瓦尔德理论的异常系统早已为人所知，罗斯和他的同事最近的工作证明了一种涉及胶体颗粒自催化生长的替代机制在低浓度下运行。他们还表明，在更浓缩的系统中，在环形成之前会形成均匀的胶体沉淀物，这显然与奥斯特瓦尔德的假设相矛盾，即环之间的空间仍然没有原子核。本文的目的是提出一种与已知事实相一致的奥斯特瓦尔德机制的解释，并以各种方式扩展普拉格和泽尔多维奇的分析。我们的 ...
Liesegang’s rings are thin precipitation bands formed when two components in solution diffuse into each other and react to form an insoluble precipitate. Ostwald’s supersaturation theory, in the quantitative form given by Prager and Zeldovitch et al., correctly predicts many features of the process of ring formation in some systems. Anomalous systems not conforming to Ostwald’s theory have been known for some time, and the recent work of Ross and co‐workers has demonstrated that an alternative mechanism involving autocatalytic growth of colloidal particles operates at low concentrations. They have also shown that a uniform colloidal precipitate is laid down prior to ring formation in more concentrated systems, which apparently contradicts Ostwald’s assumption that the spaces between rings remain clear of nuclei. The purpose of this paper is to suggest an interpretation of Ostwald’s mechanism which is compatible with the known facts, and to extend the analysis of Prager and Zeldovitch in various ways. Our ...