Development of selective nanofiltration membranes based on nanoporous organic frameworks

现代膜技术在高效节能的分离工艺方面具有巨大的潜力。特别是未来生物精馏过程中选择性纳滤技术的发展需要新的膜材料，以及对膜材料和被分离物质的结构-性能关系的基本认识。近年来，新型的纳米多孔聚合物和有机骨架受到了广泛的关注，具有广阔的应用前景。它们是很有前途的分离材料，因为可以定制各种孔隙特性以及内表面的极性。本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，并研究其在纳滤分离水溶液中应用相关模型系统5-羟甲基糠醛(HMF)/果糖中的应用。其中一个重点是新材料的开发。除了使用参考材料外，还将开发一种新的可扩展的元素有机骨架合成路线，使用格氏代替有机锂中间体。由于反应性的降低，框架结构的形成得到了更好的控制，从而能够调整孔隙性质以及内表面化学性质。通过系统地改变连接器种类，可以合成一系列具有不同表面极性的材料。通过对水溶液中HMF和果糖的液相吸附行为进行实验，评价其结构-性能关系，为液相分离技术的发展提供依据。最终，合成的聚合物以细小的不溶性粉末的形式出现，被加工成混合基质膜。研究了它们在HMF/果糖水相混合物纳滤中的分离性能。总体而言，该项目将新型多孔材料及其在生物平台化学品液相吸附中的结构-性能关系的基础研究与基于膜纳滤的新型分离技术的应用相关开发相结合，以实现未来生物炼制概念。

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.