Browsing by Author "Harismah, K."

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Open Access
Chemically uracil-functionalized carbon and silicon carbide nanotubes: computational studies
(Elsevier, 2018) Harismah, K.; Mirzaei, M.; Sahebi, H.; Gülseren, Oğuz; Rad, A. S.
Chemical additions of uracil (U) nucleobase to sidewall of each of representative (4,4) armchair carbon and silicon carbide nanotubes (CNT and SiCNT) were investigated based on density functional theory (DFT) calculations. All singular and hybrid models were optimized to obtain the minimum-energy structures. The evaluated molecular properties indicated the effects of U-attachment on properties of both of U and NT counterparts, in which additional evaluated atomic-scale chemical shifts indicated the role of atomic sites in the U-attachment processes. Both of U-CNT and U-SiCNT hybrids could be considered as achievable compounds; however, the aim of application could organize the achievement of which hybrid. There was one possibility of U-attachment for the homo-atomic system of CNT whereas there were two possibilities of U-attachment for the hetero-atomic system of SiCNT. Interestingly, the evaluated atomic and molecular properties indicated differences between the characteristics of U-SiCNT-1 and U-SiCNT-2 as an advantage of computational chemistry methodologies, in which the results were very much interesting for the water-solvated systems.
Open Access
Functionalization of (n,0) CNTs (n=3-16) by uracil: DFT studies
(Springer Heidelberg, 2018) Mirzaei, M.; Harismah, K.; Jafari, E.; Gülseren, Oğuz; Rad, A. S.
Density functional theory (DFT) calculations were performed to investigate stabilities and properties for uracil (U)-functionalized carbon nanotubes (CNTs). To this aim, the optimized molecular properties were evaluated for (n, 0) models of CNTs (n = 3-16) in the original and U-functionalized forms. The results indicated that the dipole moments and energy gaps were independent of tubular diameters whereas the binding energies showed that the U-functionalization could be better achieved for n = 8-11 curvatures of (n, 0) CNTs. Further studies based on the evaluated atomic-scale properties, including quadrupole coupling constants (CQ), indicated that the electronic properties of atoms could detect the effects of diameters variations of (n, 0) CNTs, in which the effects were very much significant for the atoms around the U-functionalization regions. Finally, the achieved results of singular U, original CNTs, and CNT-U hybrids were compared to each other to demonstrate the stabilities and properties for the U-functionalized (n, 0) CNTs.