The biomorphic mineralization employs natural bio-templates at multiple scales (nano-micro-mega) and specific bio-templates such as diatoms which are particularly interesting due to their nano-dimension with nano-features (like nanopores, nanochannels, protusions).
One of the advantages of diatoms for nanotechnology over standard methods (top-down photolithography patterned substrates) is that diatoms grow in exponentially increasing numbers on surfaces or in solutions and thus can be fabricated at large-scale to respond to industrial demand.
It is believed that such capabilities could be smartly engineered to overcome existing limitations of nanomaterials for the reinforcement of elastomeric composites used for tire applications. Indeed, a dual phase filler system can offer a new performance range if the phase morphology is combined with an architectural change which can be obtained through a CNT /Silica Nano on Nano Concept: this is the goal of the Green NanONano project.
The project proposed to smartly use the natural nanoporous structure and the capability of controlling the deposition of metallic structures via sub-atmospheric Atomic Layer Deposition processing, to create a bio-based silica substrate embedding self-organized metallic films or islands (dependent on the plasma-assisted ALD process parameters). These metallic islands will act as a nucleation site for the selective growth of carbon nanotubes (CNT) via the catalyst-mediated chemical vapour deposition process.
A controlled nano-on nano structuration based on the siliceous porous templates has been performed leading to an outside template growth of CNT thus leading to a highly effective distribution of CNT achieved through a siliceous template acting as a dispersion vector.
By using diatoms or diatomite, it would also be possible to significantly reduce the carbon share, which would also improve the ecological balance of the tire. In the laboratory, this combination has been already tested. The next step willbe to develop industrial manufacturing processes.
More information available here: https://science.lu/fr/content/green-nanonano-des-diatom%C3%A9es-pour-am%C3%A9liorer-les-pneus