Electrospun Nanofibers with Embedded Yolk-Shell Particles for Catalytic Applications

将具有催化活性的纳米颗粒集成到宏观载体中是其在多相催化中应用的关键。我们想要研究所谓的蛋黄壳颗粒在多孔电纺纤维中的嵌入以及这些新型结构的催化性能。蛋黄-壳颗粒是核壳系统，由反应物渗透性壳和单一催化活性核组成。初步结果表明，利用嵌段共聚物作为牺牲性模板和高效致孔剂，并将其额外嵌入到多孔基质中以防止聚集和融合，可以显著提高蛋黄壳颗粒的催化活性。我们计划探讨催化活性提高的原因。特别是，我们将研究通过多孔壳增加反应物的催化活性中心的可及性，以及提高颗粒抗聚集和融合的稳定性所起的作用。通过将嵌段共聚物模板法制备蛋黄壳与静电纺丝法制备纳米纤维相结合，我们将能够制备嵌入具有催化活性的蛋黄壳颗粒的纤维垫。这些宏观载体体系适用于流动式催化过程。它们将通过模型反应(催化染料降解)进行研究，并进一步应用于水净化。本项目的主要目标是：(A)利用嵌段共聚模板方法制备和研究具有催化活性核心和反应物透过性外壳的蛋黄壳型纳米催化剂，并了解增强催化活性的机理。(B)将蛋黄壳型纳米催化剂嵌入到电纺纳米纤维中，并制造具有催化活性的纤维垫。(C)研究纤维垫的催化活性及其在水净化过程中的测试(例如，催化降解作为水污染物的染料)。该项目将在德累斯顿莱布尼茨聚合物研究所和印度德里理工学院的国际研究合作框架内进行。合作伙伴的能力与印度合作伙伴在嵌段共聚树脂自组装和静电纺丝领域的优势以及德国合作伙伴在纳米粒子/纳米催化剂合成和纳米粒子/嵌段共聚聚合物纳米复合材料制备以及纤维力学和相互作用表征领域的优势是理想的互补。所获得的结果将为制备用于净水过程和环境目的的流动型催化体系提供新的概念。

The integration of catalytically active nanoparticles in macroscopic supports is crucial for their application in heterogenous catalysis. We want to investigate the embedding of so-called yolk-shell particles into porous electrospun fibers and the catalytic properties of these novel structures. Yolk-shell particles are core-shell systems, consisting of a reactant-permeable shell and a single catalytically active core. Preliminary results demonstrate that catalytic activity of yolk-shell particles may be substantially improved by using block copolymers as sacrificial template and efficient porogen and additional embedding them in a porous matrix to prevent aggregation and fusion We plan to investigate the reasons for the enhanced catalytic activity. In particular, we will study the role of increased accessibility of catalytically active sites for the reactants through the porous shell and the increased stability of particles against aggregation and fusion. By combining block copolymer template approach for the fabrication of yolk-shells with electrospinning technique for the fabrication of nanofibers, we will be able to fabricate fiber mats with embedded catalytically active yolk-shell particles. These macroscopic carrier systems are suitable for flow-type catalytic processes. They will be investigated using model reactions (catalytic dye degradation) and further applied in water cleaning. The main goals of the present project are: (a) Preparation and investigation of yolk-shell type nanocatalyst having catalytically active core and reactant permeable shell using block copolymer template approach and mechanistic understanding of enhanced catalytic activity.(b) Embedment of yolk-shell type nanocatalyst into electrospun nanofibers and fabrication of catalytically active fibrous mat.(c) Investigation of catalytic activity of fibrous mat and its testing for water purification processes (e.g. for catalytic degradation of dyes as water pollutants).The project will be carried out in frame of international research collaboration between Leibniz Institute of Polymer Research, Dresden, and Indian Institute of Technology Delhi. The competences of the partners are ideally complementary with strengths of the Indian Partner in the field of block copolymer self-assembly and electrospinning, and strengths of the German Partner in the field of nanoparticle/nanocatalyst synthesis and preparation of the nanoparticle/block copolymer nanocomposites as well as characterization of mechanics and interactions of fibers. Obtained results will lead to new concepts for preparation of flow-type catalytic systems for water purification processes and environmental purposes.