Low-dimensional nanocarbons have fascinating nanostructures, unique properties and abundant functionalities: such as high specific surface area, tunable pore structure, excellent electrical conductivity, and valuable thermal and chemical stability.
This topic aims for a broad and deep knowledge of the relationships between the phase composition / nanostructure and the properties of the target ceramic nanocomposite materials consisting of low-dimensional nanocarbon-based phases (such as nanodiamond (ND), onion-like carbon, carbon nanotubes, graphene) finely dispersed in a ceramic matrix (i.e., silica or Si3N4).
The topic includes the synthesis of novel 0D-nanocarbon-silica ceramic composites and their high-temperature evolution with a homogeneous fine distribution of nanoparticles with sizes less than 10 nm.:
The 0D-nanocarbon phase suffers a transformation from nanodiamond phase to bucky nanodiamond (with core-shell structure) to onion-like carbon as function of the temperature of thermal annealing.
Reference:
Alexander Ott, Simone Rogg, Stefan Lauterbach, Hans-Joachim Kleebe, Christian Hess, Gabriela Mera, “Novel 0D-Nanocarbon-Silica Ceramic Composites: Sol-Gel-Synthesis and High-Temperature Evolution”, Dalton Transactions 2020, 49, 7144 – 7154.
2D-Nanocarbon-based multifunctional composites can be synthesized by facile sol-gel synthesis or by polymer-derived graphene syntheses.
The achieved nanocomposites have tunable dielectric properties.
References:
Cornelia Hintze, Koji Morita, Ralf Riedel, Emanuel Ionescu, Gabriela Mera, “Facile sol–gel synthesis of reduced graphene oxide/silica nanocomposites”, Journal of the European Ceramic Society 2016, 36(12), 2923–2930.
Xifan Wang, Gabriela Mera, Koji Morita, Emanuel Ionescu, “Synthesis of polymer-derived graphene/silicon nitride-based nanocomposites with tunable dielectric properties“, Journal of the Ceramic Society of Japan, 2016, 124(10), 981-988.
Polymer-to-ceramic conversion process of single-source precursors can be used as efficient and unique tool in order to create well-defined carbon nanotubes-containing composites just by simple tailoring of the chemical structure of the precursors.
These nanocomposites possess exceptional properties, such as high electric conductivity, porous structure, high specific surface area; thus, they can find applications in several fields such as vehicle/aircraft technology, health & safety, energy storage and conversion, air/water pollution control, airspace applications, etc.
Reference:
Gabriela Mera, Peter Kroll, Ilia Ponomarev, Jiewei Chen, Koji Morita, Moritz Liesegang, Emanuel Ionescu, Alexandra Navrotsky, “Metal-Catalyst-Free Access to Multiwall Carbon Nanotubes/Silica Nanocomposites (MWCNT/SiO2) from a Single-Source Precursor”, Dalton Transactions 2019, 48, 11018-11033.
Silicon-based polymer-derived ceramics (PDCs) represent a class of materials which are produced by the controlled pyrolysis of suitable organosilicon polymers in inert or reactive atmosphere.
This procedure allows the access to novel additive-free ternary and quaternary ceramic materials which cannot be achieved using conventional processing techniques such as sintering or melting. PDCs are X-ray amorphous but nanoscopically heterogeneous materials.
One of the most intriguing features of PDCs is the presence of nanodomains of 1-3 nm in size in their structure and thus they can be regarded as intrinsic nanocomposites.
The free-carbon phase not only makes these materials “smart” but also strongly influences their thermal stability against crystallization and decomposition as well as the sizes of composing nanodomains.
References:
Bioinorganic Chemistry Encyclopedia of Inorganic and Bioinorganic Chemistry, 3rd Edition, Update 2019, John Wiley & Sons, Ltd., S. 1-26, DOI: 10.1002/9781119951438.eibc2705.
Gabriela Mera, Markus Gallei, Samuel Bernard, Emanuel Ionescu, “Ceramic Nanocomposites from Tailor Made Preceramic Polymers”, Nanomaterials 2015, 5(2), 468-540.
Emanuel Ionescu, Gabriela Mera, Ralf Riedel, “Polymer-Derived Ceramics: Materials Design towards Applications at Ultrahigh-Temperatures and in Extreme Environments”, in “Nanotechnology Concepts, Methodologies, Tools, and Applications”, Ed: Mehdi Khosrow-Pour, IGI Global Publishing 2014, 1108-1139.
Gabriela Mera, Emanuel Ionescu, “Silicon-Containing Preceramic Polymers”, Encyclopedia of Polymer Science and Technology, 2013, DOI: 10.1002/0471440264.pst591.
Gabriela Mera, Alexandra Navrotsky, Sabyasachi Sen, Hans-Joachim Kleebe, Ralf Riedel, “Polymer- Derived SiCN and SiOC Ceramics – Structure and Energetics at the Nanoscale” (Feature article), J. Mater. Chem. A 2013, 1, 3826-3836.
Paolo Colombo, Gabriela Mera, Ralf Riedel, Gian Domenico Soraru, “Polymer-derived ceramics: 40 years of research and innovation in advanced ceramics” (Feature Article and Cover Publication), Journal of the American Ceramic Society 2010, 93(7), 1805-1837.
Gabriela Mera, Ralf Riedel, “Synthesis and properties of preceramic polymers. Organosilicon-based polymers as precursors for ceramics”, pp. 51-89 in Polymer Derived Ceramics: From Nanostructure to Applications, Edited by P.Colombo, R.Riedel, G. D.Sorarù, and H.-J.Kleebe. DEStech Publications Inc., Lancaster, PA, USA (2010).
Ralf Riedel, Gabriela Mera, Ralf Hauser, Alexander Klonczynski, “Silicon-based polymer-derived ceramics: synthesis properties and applications – a review”, Journal of the Ceramic Society of Japan 2006, 114(June), 425-444.