Development of selective nanofiltration membranes based on nanoporous organic frameworks

现代膜技术在能源和成本效益的分离过程中具有巨大的潜力。特别是未来生物精炼工艺的选择性纳滤技术的发展需要新的膜材料以及对这些材料和待分离物质的结构-性质-关系的基本理解。近年来，新型纳米多孔聚合物和有机骨架材料引起了人们极大的关注，具有巨大的发展潜力。它们是有前途的分离材料，因为各种孔特性以及内表面的极性可以定制。该项目的目的是开发基于系统优化的纳米多孔聚合物的混合基质膜，并研究其在通过纳滤分离与应用相关的模型系统5-羟甲基糠醛（HMF）/果糖水溶液中的作用。一个重点是新材料的开发。除了使用参考材料，一个新的和可扩展的元素有机框架的合成路线是开发，使用格氏试剂代替有机锂中间体。由于降低的反应性，骨架结构的形成得到更好的控制，因此能够定制孔性质以及内表面化学。通过系统地改变连接体种类，合成了一系列具有不同表面极性的材料。通过对HMF和果糖在水溶液中的液相吸附行为的实验研究，探讨了HMF和果糖的结构-性质-关系，为液相分离技术的发展提供了理论依据。最后，合成的聚合物，作为精细和不溶性的粉末，被加工成混合基质膜。研究了它们在HMF/果糖水溶液混合物纳滤中的分离性能。总的来说，该项目结合了基础研究，重点是新型多孔材料领域及其在生物平台化学品液相吸附中的结构-性能-关系，以及基于膜纳滤的新分离技术的应用相关开发，用于未来的生物精炼概念。

Modern membrane technologies possess great potential for energy- and cost-efficient separation processes. Especially the development of selective nanofiltration technologies for future bio-refinery processes requires new membrane materials as well as a basic understanding of the structure-property-relations of those and the substances to be separated. Novel nanoporous polymers and organic frameworks, which have attracted considerable attention in recent years, offer great potential. They are promising materials for separation since various pore properties as well as the polarity of the inner surface can be tailored. The aim of this project is the development of mixed matrix membranes based on systematically optimized nanoporous polymers and their investigation in the separation of the application-related model system 5-hydroxymethylfurfural (HMF)/fructose in aqueous solution by nanofiltration. One focus is the development of novel materials. Besides using reference materials, a new and scalable synthesis route for element organic frameworks is to be developed, using a Grignard instead of an organolithium intermediate. Due to the decreased reactivity the formation of the framework structure is better controlled, thus, enabling the tailoring of the pore properties as well as the inner surface chemistry. By a systematic variation of the connector species a series of materials with varying surface polarity are to be synthesized. Experiments on the liquid phase adsorption behavior of HMF and fructose from aqueous solutions are conducted to evaluate structure-property-relations, which are essential for separation technology development in liquid phase processing. Ultimately, the synthesized polymers, occurring as fine and non-soluble powders, are processed to mixed matrix membranes. Their separation performance is investigated in the nanofiltration of HMF/fructose aqueous mixtures. Overall, the project combines basic research focused on the field of novel porous materials and their structure-property-relations in liquid phase adsorption of biogenic platform chemicals with the application-related development of new separation technologies based on membrane nanofiltration for future biorefinery concepts.