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.

结晶过程在过程时间内形成细细的，易溶的，结晶相，该过程在毫秒和秒的范围内称为降水结晶过程。由于在高过饱和的过程中执行该过程时，由于沉淀产品的溶解度较低，因此经济生产才有可能。在这种条件下，固体形成过程作为成核和生长的速率很高。对于能够对最终粒子特性（粒度分布，形态等）做出预测，必须清楚粒子形成机制的关键步骤。可以通过沉淀获得的典型粒径在20 nm至10微米之间。因此，在足够高的过饱和水平下，固体的沉淀是产生纳米颗粒的方法之一。这些颗粒可以通过一系列二级过程，例如聚集，再结晶和衰老，这可以显着影响最终获得的沉淀物的性质。该研究建议的目的是阐明以下假设：在粒子生长过程中，渗透相互作用在粒子生长过程中具有重要性，对主要颗粒的聚集具有重要性。初步估计将这种有吸引力的相互作用的特征是相对较强且短距离。在文献中，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。在线X射线衍射与同步加速器辐射是一种研究这种效果的有前途的实验方法。 X射线衍射测量与其他实验方法结合使用，应使用适当的建模方法来解释。为此，必须在其当前状态之外开发现有的在线X射线衍射方法，以进行降水过程。该研究的重点是降水过程中粒子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。