Project

Discipline

nanomaterials; oxides; polyoxometalates; composite materials; drug delivery; synthetic techniques; in situ investigations; hydrothermal synthesis

Lead
Lay summary
Oxide materials are indispensable tools for a future nanotechnology and for the solution of  key contemporary research issues, such as water treatment, gas sensing and new energy sources. However, the way to oxide-based nanotechnological innovations is still challenging with respect to the controlled transformation of the multitude of oxide structures onto nanoscale dimensions. The present project is therefore focused on the targeted synthesis of oxide materials with high impact on current energy, environmental and health technology. PART 1: Polyoxometalates - Crystal Engineering and Materials Development Polyoxometalates (POMs) are a fascinating class of oxocluster materials with transition metal elements (preferably Mo, W and V) in their high oxidation states. POMs keep attracting worldwide research interest due to the multitude of their structural architectures and their impressive range of properties, such as catalytic activity, magnetism and bio-medical features (cf. PART 2). Over the past years, we have focused on the construction of large polyoxotungstates using lanthanoid cations as versatile structural linkers. The potential of systematic approaches still remains to be explored with polyoxomolybdate components that can offer an even more flexible coordination chemistry. Mixed metal W/Mo-POMs and related materials will be synthesized to open up new functionalization pathways for catalysis and medical applications. PART 2: Nanostructured Composites Hybrid materials are at the forefront of current research activities, because they integrate key properties of organic and inorganic compounds in a synergistic fashion. The combination of POMs with bio-macromolecules, such as chitosan and its derivatives, is a particularly interesting field: here, the antiviral, anticancer and antibacterial activity of POMs can be implemented into a biocompatible functional matrix. Carboxymethyl chitosan (CMC), for example, offers excellent drug carrier properties and biodegradability. PART 2 is thus focused on the synthesis of nanoscale composites through the encapsulation of bio-active POMs into CMC and related biopolymers in close connection with PART 1. In order to fully tap the medical application potential of POMs and their nanocomposites, their cellular uptake mechanisms will be studied for the development of new drug delivery strategies. PART 3: Novel Synthetic Methods The development of flexible, tunable and straightforward synthetic methods is essential for the nanotechnological implementation of oxide materials. Simultaneous control over structure, composition and morphology is requested for the targeted nanoscale synthesis of complex oxide materials which often provide the most interesting properties. We thus work at the frontiers of oxide synthesis: the nanoscale production of new and catalytically active W- and Mo-based oxide systems as well as of versatile nanostructured spinels will be explored with a wide arsenal of state-of-the-art synthetic techniques. The emerging nanoscale functional oxides will be tuned for environmentally important applications, e.g. photocatalytic wastewater treatment and water oxidation or miniaturized sensor technology. Furthermore, we aim for innovative mechanistic in situ studies of microwave-hydrothermal processes.

Direct link to Lay Summary

Last update: 21.02.2013

Active participation

Number	Title	Start	Funding scheme

1. SUMMARY AND GOALS OF THE PROPOSED RESEARCHOxide materials are indispensable tools for a future nanotechnology and for the solution of our most urgent environmental and energy issues: their wide range of applications encompasses catalysis, battery technology, sensors, superconducting devices, new displays and light sources or diagnostic nano-medicine - just to mention a few. However, one major roadblock remains to be overcome on the way to oxide-based nanotechnological innovations - and this is the controlled transformation of the multitude of structural oxide varieties onto nanoscale dimensions. The present project is therefore focused on the targeted synthesis of oxide materials with a high impact on current energy, environmental and health technology.PART 1: Polyoxometalates - Crystal Engineering and Materials DevelopmentPolyoxometalates (POMs) are a fascinating class of oxocluster materials with transition metal elements (preferably Mo, W and V) in their high oxidation states. POMs come along in a multitude of structural architectures that keep attracting worldwide research interest. This structural diversity leads to an impressive range of POM properties, such as catalytic activity, magnetism and bio-medical features (cf. PART 2). Over the past years, we have focused on the construction of large polyoxotungstates using high-coordinated and oxophilic lanthanoid cations as structural linkers. However, the potential of this approach still remains to be explored with polyoxomolybdate components that can offer an even more flexible coordination chemistry. Their combination with lanthanoid linkers will open up new perspectives in the chemistry of mixed metal W/Mo-POMs and their functionalization for medicinal applications.PART 2: Nanostructured CompositesHybrid materials are in the forefront of current research activities, because they integrate key properties of organic and inorganic compounds in a synergistic fashion. The combination of POMs with bio-macromolecules, such as chitosan and its derivatives, is a particularly interesting field: here, the antiviral, anticancer and antibacterial activity of POMs can be merged with a biocompatible functional matrix that offers wound-healing and tissue-engineering properties. PART 2 is thus focused on the synthesis of nanoscale composites through the encapsulation of antiviral POMs into carboxymethyl chitosan (CMC) and related biopolymers in close connection with PART 1. Our recent biochemical investigations on antiviral POMs inspired us to fully tap the medicinal potential of POMs by studying their cellular uptake mechanisms for the development of new drug delivery strategies.PART 3: Novel Synthetic MethodsThe development of flexible, tunable and straightforward synthetic methods is essential for the nanotechnological implementation of oxide materials. However, the targeted nanoscale synthesis of complex oxide materials - which often provide the most interesting properties - remains a considerable challenge that requires simultaneous control over structure, composition and morphology. We thus work at the frontiers of oxide synthesis: the nanoscale production of new and catalytically active W- and Mo-based oxide systems as well as versatile nanostructured spinels will be explored with a wide arsenal of state-of-the-art synthetic techniques (from microwave-hydrothermal over sonochemical reactions to flame syntheses). The emerging nanoscale functional oxides will be tuned for environmentally important applications, e.g. photocatalysis and miniaturized sensor technology. Furthermore, we aim for pioneering mechanistic in situ studies of microwave-hydrothermal processes.