Biography
C H Wong has his expertise in Monte Carlo simulation and ab-initio calculation in Material Science. He has passion in searching for 300 K superconductors. He admitted in an experimental physics group and was trained to conduct AC calorimetry in the resolution better than 5 decimal places during his Doctoral degree in Hong Kong. He made contributions in capturing tiny superconducting signals in nanostructured materials and also discovered more fundamental physics of superconductors based on the ultra-weak heat capacity anomaly. After he graduated in 2015, he explores in theoretical condensed matter physics as a Post-doctoral Researcher in Russia, in order to design high temperature superconductors from theoretical point of view. He has constructed a stochastic model for carbon nanowire carrying extremely large Debye frequency and proposes the algorithm towards stabilized carbon nanowires array.
Abstract
In the present work, we develop a powerful Monte Carlo algorithm of the carbon nanowires ordered into 3D hexagonal array. A new routine has been developed to probe the phase transition between the alpha and beta carbyne based on the chemical bond and atomic distributions. Our model confirms that the cumulene is the more preferable phase at low temperatures, but it is switched into polyvne phase at high temperatures. The bond softening temperature across Peierls transition is observed at 480 K. The higher Peierls transition temperature is observed in the presence of interstitial doping despite the transition temperature shows length-independence. The elastic modulus of the carbon chains is 1.7 TPa at 5 K and the thermal expansion is +70 µ K-1 at 300 K via. monitoring the collective atomic vibrations and chemical bond distributions. Thermal fluctuation in terms of heat capacity as a function of temperatures shows that the melting point is around 3800 K. The carbon atoms along the carbon nanowire arranged in relaxed state is unveiled at the end.
Biography
Ervin Å est has his expertise in evaluation and passion in improving the sustainable energy resources. He is developing and preparing innovative paint coatings for solar application. He is also evaluating the prepared materials and applied coatings. He obtained a degree in the field of dye sensitized cells and developed effective method of sintering TiO2 as the working electrode. Now, he is a young researcher at the National Institute of Chemistry Slovenia and studying nanosciences and nanotechnologies at the Josef Stefan International Postgraduate School.\\r\\n\\r\\nResearch interest: sol-gel thin films; modification of pigments for spectrally selective paint coatings; surface treatments and nanocoatings; dye sensitized solar cells; electron microscopy, sample preparation
Abstract
When developing new, commercially available products, nanostructured materials are receiving an increasing amount of interest. Transition from fossil fuel to sustainable sources of energy is essential. Solar energy is a promising alternative energy source that can address this challenge. Platelets graphene as flake like material is one of the nanomaterials suitable for improvement of spectrally selective coatings. Synthesized platelets graphene was used as a corrosion protection agent while also serving as a solar absorbing pigment. The main obstacle in the synthesis of platelets graphene is agglomeration of the particles, thus they have to be functionalized. With the functionalization of the particles the application of the prepared dispersions is simple and infusion of platelets graphene less evident. High absorptivity is expected due to the platelets graphene structure. The latter is also a candidate for an improvement of the corrosion inhibition effect. Raman spectroscopy, atomic force microscopy and transmission electron microscopy were used to characterize prepared platelets graphene (especially for the definition of the layers) and coatings. In addition to the proposed techniques, the Fourier Transformation Infrared spectroscopy and UV-Vis spectroscopy were introduced to characterize optical properties of the coating. The presented results demonstrate improvements of spectrally selective coatings for low temperature application.