Continuous classification of nanoparticles by selective agglomeration according to size, composition and surface properties

该项目的目的是开发一种可扩展的、连续操作的工艺，用于通过选择性团聚对20纳米以下的胶体纳米颗粒（NPs）进行多维分离。选择性团聚是通过添加适当的非溶剂（差液）对不稳定的NPs进行逐渐絮凝，然后进行群隔离，而更稳定的NPs则作为分散良好的初级颗粒留在溶液中。通过结合不同的选择性团聚步骤，实现了根据尺寸、成分和表面性质的多维分馏。第二个筹资期的重点将是三个方面。首先，多维分离将在实验室规模上通过批量模式下不同选择性聚集的串行连接进行演示。核心挑战是根据粒径和成分或粒径和表面性质确定单个分离步骤的最佳顺序，以实现真正的二维分馏。此外，还将分析通过该PP的合作伙伴提供的与其他分离策略的适当组合。然后，将选择至少一个串行批处理程序，并将其扩展为真正的连续过程。这就带来了采用浓度、停留时间和流速比的挑战，通过选择性团聚的各个分离步骤可以在一个连续的操作线上相互结合。过程控制是必要的，以自动实现交替操作的膜模块之间的切换，在羊群隔离时，选择性团聚应用。最后，为相纯材料开发的概念将被推广，并使更复杂的，但技术上高度相关的有机-无机杂化材料易于使用。在这里，石墨烯杂化TiO2颗粒（光催化）和碳功能化Si颗粒（电池负极材料）将作为基准材料。它们的共同之处在于，在加工过程中，特别是在分散过程中，会产生与目标材料的表面特性严重偏离的新表面。因此，对于高性能光催化剂或电池阳极，在经过粉末合成、粉末悬浮和分散的顺序后，必须实现尺寸和表面性质的二维分离，而不符合规格的颗粒则需要进行分类和回收。在本PP结束时，选择性团聚将被建立为胶体NPs的可扩展，多维分类的强大方法。此外，将制定多维NP表征的新标准，并将与其他分离策略（离心，（di）电泳，浮选）进行适当的组合，并与合作伙伴一起确定和评估其局限性和机会。

Aim of this project is the development of a scalable, continuously operated process for the multidimensional separation of colloidal nanoparticles (NPs) below 20 nm via selective agglomeration. Selective agglomeration is based on the gradual flocculation of less stable NPs by the addition of an appropriate non-solvent (poor liquid) and subsequent flock isolation, while more stable NPs stay as well-dispersed primary particles in solution. By combining distinct steps of selective agglomeration, multidimensional fractionation according to size, composition and surface properties is achieved. The focus of the second funding period will be threefold. First, multidimensional separation will be demonstrated on lab-scale via the serial connection of different selective agglomerations in batch mode. Central challenge is to identify the best sequence of individual separation steps to achieve true 2D fractionation according to size and composition or size and surface properties. In addition, appropriate combinations with other separation strategies, that are available via the collaboration partners of this PP, will be analyzed as well. Then, at least one serial batch procedure will be selected and scaled up to a truly continuous process. This comes with the challenge of adopting concentrations, residence times and flow rate ratios in such a way that individual separation steps by selective agglomeration can be combined with each other in one continuous operation line. Process control is compulsory to automatically realize the switch between alternatingly operated membrane modules during flock isolation when selective agglomeration is applied. Finally, the concepts developed for phase-pure materials will be generalized and made accessible to more complex, however technically highly relevant organic-inorganic hybrid materials. Here graphene hybridized TiO2 particles (photocatalysis) and carbon functionalized Si particles (anode material in batteries) will be used as benchmark materials. They have in common that during processing, in particular during dispersion, new surface is created that in parts strongly deviates from the surface properties of the target material. Thus, after the sequence of powder synthesis, powder suspension and dispersion, 2D separation by size and surface properties must be realized for high performance photocatalysts or battery anodes, while particles not matching the specifications need to be sorted out and recycled. At the end of this PP, selective agglomeration will have been established as a powerful method for the scalable, multidimensional classification of colloidal NPs. Moreover, new standards for multidimensional NP characterization will have been developed and suitable combinations with other separation strategies (centrifugation, (di)electrophoreses, flotation) will have been identified and evaluated with regard to their limitations and opportunities together with the collaboration partners.