11 documents found, page 1 of 2
Self-assembled diphenylalanine peptide microtubes covered by reduced graphene o...
Ivanov, M. S.; Khomchenko, V. A.; Salimian, M.; Nikitin, T.; Kopyl, S.; Buryakov, A. M.; Mishina, E. D.; Salehli, F.; Marques, P. A. A. P.
Surface modified hydroxyapatites with various functionalized nanostructures: co...
Bystrova, V. S.; Paramonova, E. V.; Bystrova, A. V.; Pullar, R. C.; Kopyl, S.; Tobaldi, D. M.; Piccirillo, C.; Avakyan, L. A.; Coutinho, J.Hydroxyapatite (HAp) has structural features that define its basic physical properties, which have an important role at the surface, and it is one of the most used materials in bone implants. In this work, we present a density functional modeling (DFT) study of HAp both as bulk and with special HAp models with various defects, especially oxygen vacancies in HAp surface layers, which can also determine photocata...
Oxygen vacancies, the optical band gap (Eg) and photocatalysis ofhydroxyapatite...
Bystrov, V. S.; Piccirillo, C.; Tobaldi, D. M.; Castro, P. M. L.; Coutinho, J.; Kopyl, S.; Pullar, R.Hydroxyapatite (Ca10(PO4)6(OH)2, HAp) is a calcium phosphate employed both in biomedicine and forenvironmental remediation. It is known that HAp can also be photocatalytic under UV light, probablydue to oxygen deficiencies, but the mechanism is unclear, and reported optical band gap energies varygreatly. For the first time we propose the mechanisms and precise kinds of vacancies which may causethe photocatalyti...
Glycine nanostructures and domains in beta-glycine: computational modeling and ...
Bystrov, V. S.; Seyedhosseini, E.; Bdikin, I. K.; Kopyl, S.; Kholkin, A. L.; Vasilev, S. G.; Zelenovskiy, P. S.; Vasileva, D. S.; Shur, V. Ya.In this work computational molecular modeling of -glycine nanostructures is presented, using various approaches, mostly semi-empirical quantum approximation PM3 type in HyperChem software in restricted Hartree-Fock calculations. The main aims of present studies focus on the molecular modeling for the -glycine domains and domain walls formation and interaction. Obtained results are presented in visual 3D-models ...
Oxygen vacancies, the optical band gap (E-g) and photocatalysis of hydroxyapati...
Bystrov, V. S.; Piccirillo, C.; Tobaldi, D. M.; Castro, P. M. L.; Coutinho, J.; Kopyl, S.; Pullar, R. C.Hydroxyapatite (Ca-10(PO4)(6)(OH)(2), HAp) is a calcium phosphate employed both in biomedicine and for environmental remediation. It is known that HAp can also be photocatalytic under UV light, probably due to oxygen deficiencies, but the mechanism is unclear, and reported optical band gap energies vary greatly. For the first time we propose the mechanisms and precise kinds of vacancies which may cause the phot...
Low-temperature photoluminescence in self-assembled diphenylalanine microtubes
Nikitin, T.; Kopyl, S.; Shur, V. Ya; Kopelevich, Y. V.; Kholkin, A. L.Bioinspired self-assembled structures are increasingly important for a variety of applications ranging from drug delivery to electronic and energy harvesting devices. An important class of these structures is diphenylalanine microtubes which are potentially important for optical applications including light emitting diodes and optical biomarkers. In this work we present the data on their photoluminescent proper...
Bioferroelectricity in Nanostructured Glycine and Thymine: Molecular Modeling a...
Bystrov, V. S.; Seyedhosseini, E.; Bdikin, I.; Kopyl, S.; Neumayer, S. M.; Coutinho, J.; Kholkin, A. L.Nanostructured aminoacid glycine and nucleobase thymine are very important for various biomedical applications. Experimentally, these structures demonstrate piezoelectric and polar properties. But the value of polarization and its switching behavior are not clear yet. In this work, computational modeling of glycine polymorphic phases (alpha and beta) and thymine nanostructures was performed using a combined met...
Piezoelectricity and ferroelectricity in biomaterials: Molecular modeling and p...
Bystrov, V. S.; Seyedhosseini, E.; Kopyl, S.; Bdikin, I. K.; Kholkin, A. L.Piezoelectricity is one of the important functional properties inherent to many biomaterials. It stems from the non-centrosymmetric crystal structure of most biopolymers including proteins, polysaccharides, and lipids. Understanding the relationship between the generated electric field and applied mechanical stress has become the main motivation to studying piezoelectricity in biological systems and artificial ...
FMR study of carbon nanotubes filled with Fe3O4 nanoparticles
Kopyl, S.; Timopheev, A. A.; Bystrov, V. S.; Bdikin, I.; Teixeira, B. M. S.; Maevskij, E.; Sobolev, N. A.; Sousa, A. C. M.Ordered arrays of carbon nanotubes were produced using a non catalytic chemical vapour deposition. The multiwall nanotubes with an inner diameter of 120 nm were grown inside porous alumina templates and then filled with a magnetic colloid of 7.5 nm Fe3O4 particles. X-ray diffraction, electron microscopy and ferromagnetic resonance (FMR) were used to characterize structural and magnetic properties of the grown s...
A Computational Study of the Properties and Surface Interactions of Hydroxyapatite
Bystrov, V. S.; Paramonova, E. V.; Costa, M. E. V.; Santos, C.; Almeida, M.; Kopyl, S.; Dekhtyar, Yu.; Bystrova, A. V.; Maevsky, E. I.; Pullar, R. C.Hydroxyapatite (HAP, Ca-10(PO4)(6)(OH)(2)) was studied from first principles approaches using the local density approximation (LDA) method in combination with various quantum-chemical (QM) and molecular mechanical (MM) methods from HypemChem 7.5/8.0. The data then were used for studies of HAP structures, and the interactions of HAP clusters with ionic species such as citrates. Computed data show that HAP can co...