18-28 October 2019

Prof. Beti Andonovik

Home Institution
Faculty of Technology and Metallurgy, Skopje, N. Macedonia

Host Contact
Prof. Jasmina Djordjevic

Host Institution
University of Nis, Nis, Serbia

Aim of the mission
Within the framework of this STSM visit, it was dealt with recent results in modelling and structural characterization of experimentally obtained carbon nanomaterials: graphene and CNTs, including research and development or improvement of models for obtaining graphene and CNTs samples’ number of layers. The type of models considered to be developed or improved use spectroscopy data (XRD and Raman) and rely on TEM and SEM data as control methods, to obtain new results and broaden the research field relevant to recent results. The common part of the STSM was gathering and summarizing information about the present situation in the field, and to define the exact problems to be solved. During the research process appropriate computer software (Mathematica) for calculation, simulation and programming was used.

Summary of the results
There were several results obtained that are relevant to the purpose of the COST Action CA17139. Main results were obtaining some of the topological indices (molecular descriptors) of experimentally obtained CNTs using their Raman spectra data, as well as TEM and SEM images. Other results are related to the need and the possibility of calculating the same indices for experimentally obtained graphene samples. All of the obtained results contribute to the use of topological indices for advanced characterization of carbon nanomaterials. Some of our summarized results offer an approach that combines several techniques. It is the first direct application of graph theory upon nanotubical structures experimentally obtained by electrolysis in molten salts using non-stationary current regimes. The spectroscopic data enables studying the diameters and performing an (n,m) assignment of nanotube samples. Using the graph representation and the chirality of the studied samples, different distance based topological indices (Wiener, Balaban, Sum-Balaban, and Gutman indices) have been evaluated in order to enable further prediction of index-related properties of the molecules.

All the results that were obtained, as expected, completed several parts of an ongoing research, and are already in a process of being prepared for publishing in international journals and presented in international scientific meetings. It is anticipated that papers on the above-mentioned topics will be submitted and most of them accepted for publication in well-known scientific journals by the end of the CA17139. There is a paper with some of the results submitted and recently accepted for publication in Balkan Journal of Applied mathematics and Informatics (to be published in December). It is also intended that the main results will be presented at important international conferences during and following the CA17139. The results of this collaboration we expect to be highly applicable, hence to give a significant contribution in practice too, in the applied mathematics and mathematical modelling. Benefits for the partner countries would be dominantly scientific, although after finishing the CA17139 subsequent applications with direct economical benefits can be expected, and also, which is highly significant, it will strengthen the links between the partner countries.