On the importance of osmotic interaction during precipitation crystallization

关于沉淀结晶过程中渗透相互作用的重要性

基本信息

批准号：
249430102
负责人：
Professor Dr.-Ing. Matthias Kind
金额：
--
依托单位：
Institut für Thermische Verfahrenstechnik (TVT)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2014
资助国家：
德国
起止时间：
2013-12-31 至 2015-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/249430102?language=en
关键词：
importance osmotic interaction during precipitation

项目摘要

Crystallization processes which form a fine, sparingly soluble, crystalline phase at process times which are in the range of milliseconds and seconds are called precipitation crystallization processes. Due to the low solubility of the precipitated products economic production is only possible, if the process is performed at high supersaturation. Under such conditions, solid formation processes as nucleation and growth run very high rates. Crucial steps of the particle formation mechanism must be clear for being able to make predictions about the final particle properties (particle size distribution, morphology, etc.). Typical particle sizes that can be obtained by precipitation, are between 20 nm and 10 microns. Thus, at sufficiently high supersaturation levels precipitation of solids is one of the methods for producing nanoparticles. These particles can pass through a series of secondary processes such as agglomeration, recrystallization and aging, which can significantly affect the properties of the finally obtained precipitate.The aim of this research proposal is to clarify the hypothesis that during particle growth osmotic interaction is of importance for aggregation of primary particles. Preliminary estimation characterizes this attractive interaction to be comparatively strong and of short-range. In literature the osmotic interaction and its influence on particle formation during the precipitation has not yet been reported. In-line X-ray diffraction with synchrotron radiation is a promising experimental method for investigating this effect. X-ray diffraction measurements combined with other experimental methods shall be interpreted with appropriate modeling approaches. To this end the existing in-line X-ray diffraction method for the investigation of precipitation processes has to be developed beyond its current status. The focus of the investigation is on the time-resolved observation of particle formation during precipitation processes and their interpretation with respect to the a qualitative and quantitative understanding of the osmotic interaction.

在毫秒和秒范围内的处理时间内形成精细的微溶结晶相的结晶过程称为沉淀结晶过程。由于沉淀产物的溶解度低，只有在高过饱和度下进行该过程才能实现经济生产。在这种条件下，固体形成过程如成核和生长速度非常快。颗粒形成机制的关键步骤必须明确，以便能够预测最终颗粒特性（颗粒尺寸分布、形态等）。可通过沉淀获得的典型颗粒尺寸在 20 nm 至 10 微米之间。因此，在足够高的过饱和水平下，固体沉淀是生产纳米颗粒的方法之一。这些颗粒可以经历一系列二次过程，如附聚、重结晶和老化，这些过程可以显着影响最终获得的沉淀物的性质。本研究计划的目的是澄清颗粒生长过程中渗透相互作用很重要的假设用于初级粒子的聚集。初步估计，这种吸引力相互作用较强，且范围较短。文献中尚未报道渗透相互作用及其对沉淀过程中颗粒形成的影响。同步加速器辐射的在线 X 射线衍射是研究这种效应的一种有前途的实验方法。 X 射线衍射测量与其他实验方法相结合应使用适当的建模方法进行解释。为此，现有的用于研究降水过程的在线 X 射线衍射方法必须超越其当前状态。研究的重点是对沉淀过程中颗粒形成的时间分辨观察及其对渗透相互作用的定性和定量理解的解释。