Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - MAEROSTRUC (Multicomponent Aerogels with Tailored Nano-, Micro- Macrostructure)

Teaser

There is a strong demand for materials with new and defined physical properties like e.g. conductivity, charge carrier separation ability or multifunctionality, which can have impact for various application fields such as electrodes and batteries, sensors, (photo)catalysis...

Summary

There is a strong demand for materials with new and defined physical properties like e.g. conductivity, charge carrier separation ability or multifunctionality, which can have impact for various application fields such as electrodes and batteries, sensors, (photo)catalysis, solar cells, membranes and touch screen devices. Nanotechnology is a promising research field which partially addresses the development of such materials. Aerogels and hydrogels from nanocrystal building blocks are a fascinating novel class of materials with extremely low densities and large specific surfaces, which partially exhibit the advantageous properties of their nanoscopic building blocks (e.g. size quantized fluorescence or catalytic activity).
The aim of the present project is to synthesize multicomponent gels with controlled mechanical properties, plasmon enhanced fluorescence, photocatalytic properties, and with controlled conductivity properties. These new materials shall not only exhibit the nanoscopic properties of their building blocks, but they will also exhibit new properties which are neither accessible from nanoparticle nor from bulk material. This will e.g. be achieved due to nanoscopic interactions between the materials or due to synergistic combination effects caused by appropriate material combination.
The project has the following three main objectives:
New synthetic techniques will be developed, which will allow a detailed control over the nanoscopic, microscopic and macroscopic composition of such aerogels from multiple components. Accordingly, new multicomponent hydrogel and aerogel materials will be developed with such a high degree of control over the compound distribution in the multicomponent gel materials. A detailed understanding of the influence of the compound distribution on the physical and chemical properties of such materials will be achieved.

Work performed

The laboratories were adapted to the project requirements. The research instruments were acquired and tested. The doctoral students who will work on the project have been hired, so that the starting configuration of the team is ready. In our research, various types of nanoparticles differing in size, shape and composition could be synthesized. We have characterized them by optical spectroscopy, electron microscopy and electrochemically. In our works, we were able to synthesize also previously unknown nanoparticles with new physicochemical properties. The nanoparticles are the building blocks for our gels, which can be seen as self-supporting networks from these nanoparticle building blocks extending to the macroscopic size regime. Our research therefore includes the investigation of possibilities to form such networks - gel formation routes. Various gel formation routes were tested and depending on the respective building blocks, the best gelation routes were selected to form such macroscopic gels. One of the gelation routes was developed by our group which is easily applicable to all types of aqueous solutions of nanoparticle building blocks. In this route, directly aerogels are synthesized without the need of so-called supercrytical drying (the transfer from liquid to gas environment, which is sometimes technically challenging). We have found out that this new gelation technique is also suitable for making aerogels from two different components of nanoparticles. Our investigations show that we can even control the microscopic distribution of the two components within the aerogels by controlling the nanoparticle surface chemistry. Another important novelty is that all possible mixing ratios of the two components are possible. Of the new gels developed, we were able to investigate the new physical and chemical properties, e.g. by elecron microscopy and spectroscopic techniques. Further works concentrated on developing shaping methods of the gels. In first publications, the main results achieved so far are described and discussed in detail.

Final results

\"As described more in detail in the section above \"\"... main results achieved so far\"\", the progress beyond the state of the art can be summarized as follows: nanoparticles which have not been reported previously have been synthesized and characterized. Lyogels and aerogels which have not been reported previously have been synthesized by employing nanoparticles as building blocksand characterized. We were able to achieve structural control on the microscale in a way which was formally not achievable. This has lead to materials with new physicochemical properties.
The expected results until the end of the project will be: New synthetic techniques will have been developed, which will allow a detailed control over the nanoscopic, microscopic and macroscopic composition of aerogels from multiple components. Accordingly, new multicomponent hydrogel and aerogel materials will have been developed with such a high degree of control over the compound distribution in the multicomponent gel materials. A detailed understanding of the influence of the compound distribution on the physical and chemical properties of such materials will have been achieved.
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