Hybrid nanomaterials for low-friction polymer composites and energy conversion
The goals of the project are to understand the growth mechanisms of hybrid nanomaterials based on “mama”-tubes, their interaction with the polymer matrix and to evaluate possible directions in application of these novel materials in tribology, photovoltaics and in energy storage. Our role in the project is to study the self-lubricating coatings based on these novel materials and to attempt to control the tribological properties of the produced composites.
The project addresses some promising challenges in material science, especially of nanotubes and nanowires, in four interconnected research fields:
- investigation of the structure and growth mechanisms of an unique and recently discovered morphology of hybrid nanostructures, i.e. fullerene-like nanospheres, nanoboxes and nanotubes embedded inside larger nanotubes, called “mama”-tube hybrids,
- determination of the efficiency of hydrogen storage into MoS2 nanotubes and “mama”-tubes and into MoOx and WOx nanowires,
- fabrication of polymer composites using the nanohybrids listed above with the aim to prepare applicable self-lubricating coatings for low-friction purposes and energy conversion, particularly for photo-active component of solar cell,
- dissemination and protection of the knowledge developed in this project, which is relevant for industrial exploitation.
The ultimate goals of the project are therefore to understand the growth mechanism of hybrid nanomaterials based on “mama”-tubes, their interaction with the polymer matrix and to evaluate possible directions in application of these novel materials in energy saving through reduced friction, in energy production using photovoltaic and in energy storage by hydrogen and lithium intercalation.
Our research group is mainly responsible for the 3rd research field of the project, which is the preparation of the composite materials on the basis of MoS2 and WS2 nano-hybrids for the applicable self-lubricating coatings. Concerning polymeric materials, it is well known that controlled amounts of oxides and other ceramic particles embedded in the polymeric matrix improve their mechanical properties, like hardness and wear resistance. However, the radical innovation in the present project consists of the incorporation of “mama”-tubes, coaxial nanotubes and other hybrid nanomaterials, which apart from improving mechanical properties will also have a strong influence on the tribological properties of these composite materials. These new polymer/nanomaterial composites and their exfoliation at the exposed surface under the mechanical load cause a formation of a tribofilm, which inflicts a reduction of friction and wear and also forms an anti-corrosive protective coating. The results of tribological experiments will also be compared with testing of these materials as additives to oils and greases and the study includes variation of several experimental parameters. Namely, while macroscopic friction can be attributed to the collective phenomena related to surface roughness, we can make use of the atomic force microscopy to focus on an individual surface asperity and thus eliminate the influence of topography and obtain the fundamental friction effects. And friction itself is of key importance for the technology, especially with modern trends for efficient consumption of fossil fuels and energy in general.