A5085364934- Carbon Nanotubes in Composites
- Graphene research and applications
- Thermal properties of materials
- Fullerene Chemistry and Applications
- Bone Tissue Engineering Materials
- Additive Manufacturing and 3D Printing Technologies
- High-pressure geophysics and materials
- Orthopaedic implants and arthroplasty
- Diamond and Carbon-based Materials Research
- Phase Equilibria and Thermodynamics
- Quantum, superfluid, helium dynamics
- Advanced materials and composites
- nanoparticles nucleation surface interactions
- Chemical Thermodynamics and Molecular Structure
- Material Dynamics and Properties
- Mechanical and Optical Resonators
- Material Properties and Applications
- Boron and Carbon Nanomaterials Research
- Tribology and Wear Analysis
- Nanoparticles: synthesis and applications
- thermodynamics and calorimetric analyses
- Laser-Ablation Synthesis of Nanoparticles
- Engineering Technology and Methodologies
- Surface Treatment and Coatings
- Thermodynamic and Structural Properties of Metals and Alloys
National Academy of Sciences of Ukraine
2013-2025
B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine
2015-2025
Polish Academy of Sciences
2024
National Research Tomsk State University
2017-2021
Tomsk Polytechnic University
2017-2021
The specific heat at constant pressure C(T) of bundles single-walled carbon nanotubes (SWNTs) closed their ends has been investigated in the temperature interval 2–120 K. It is found that curve features near 5, 36, 80, and 100 experimental results on radial thermal expansion coefficient αR(T) SWNTs oriented perpendicular to sample axis have compared. curves exhibit a similar behavior T > 10 dependence Grüneisen γ(T) calculated. also feature 36 Above K practically independent (γ ≈ 4)....
The low-temperature dependence of the heat capacity Ne cryocrystals was analyzed. A hump that appears as a local maximum in curve is shown C/T3 vs T at Tmax. It observed with increasing molar volume, Tmax shifts to lower temperatures. universal empirical relation Δ∗ proposed describe excess (non-Debye) low value function depends on both magnitude anomaly and temperature which occurs, but remains independent volume for noble gas cryocrystals. This study provides new information about...
The Vickers hardness and Young's modulus of the hydroxyapatite (HA) bioceramics with a small amount multi-walled carbon nanotubes (MWCNTs) were studied by using ultramicrotester Shimadzu for dynamic tests DUH-211. Small concentrations MWCNTs from 0.05 to 0.5 wt.%. argon inert atmosphere vacuum condition taken prevention oxidation. Brunauer-Emmett-Teller (BET) surface area SBET HA-MWCNTs composites was determined thermal adsorption-desorption nitrogen. It found that sintered in Ar atmosphere,...
The specific heat of multi-walled carbon nanotubes (MWCNTs) with a low defectiveness and content inorganic impurities has been measured in the temperature range from 1.8 to 275 K by thermal relaxation method. elemental composition morphology MWCNTs were determined using scanning electron microscopy analysis energy dispersion x-ray spectroscopy. prepared chemical catalytic vapor deposition have mean diameters 7 nm up 18 lengths some tens microns. purity is over 99.4 at.%. mass samples ranged...
The heat capacity of bundles closed-cap single-walled carbon nanotubes (SWNT) with one-dimensional chains nitrogen molecules adsorbed in the grooves has been first experimentally studied at temperatures from 2K to 40K using an adiabatic calorimeter. contribution C(T) total separated. In region 2-8K behaviour curve is qualitatively similar theoretical prediction phonon 1D krypton (Kr) atoms localized SWNT bundles. Below 3K dependence linear. Above 8K becomes steeper comparison case Kr atoms....
The experimental studies of the heat capacity 1D chains xenon atoms adsorbed in outer grooves bundles closed single-walled carbon nanotubes CXe have been first made at temperature range 2–30 K with adiabatic calorimeter. data compared theory [A. Šiber, Phys. Rev. B 66, 235414 (2002)]. and theoretical curves are close below 8 K. Above curve CXe(T) exceeds one excess ΔCXe(T) increases monotonously temperature. We assume that caused mainly by increase distance between neighboring chain increasing
DSC and calorimetric studies of multi-walled carbon nanotubes (MWCNTs) with average diameters in the range 7, 9 18 nm were carried out. MWCNTs obtained by CVD method. The kinetic processes studied from room temperature to 550 °C a nitrogen flow using differential scanning calorimetry (DSC) on Perkin – Elmer — 8000. It was found that exo- endothermic peaks are not observed curves after water evaporation. This indicates all have small number defects, functional groups, other impurities. heat...
The heat capacity at constant pressure of fullerite C60 has been investigated using an adiabatic calorimeter in a temperature range from 1.2 to 120 K. Our results and literature data have analyzed interval 0.2 300 contributions the intramolecular lattice vibrations into separated. contribution vibration becomes significant above 50 Below 2.3 K experimental dependence is described by linear cubic terms. limiting Debye T→0 estimated (Θ0 = 84.4 K). In 30 curve describes rotational tunnel...
Structural disorder and temperature behavior of specific heat in multi walled carbon nanotubes (MWCNTs) have been investigated. The results X-ray diffractometry, Raman spectroscopy, transmission electron microscopy (TEM) images are analyzed. thermodynamic theory the zigzag-armchair domain structure formation during nanotube synthesis is developed. influence structural on size domains was estimated at ~40 nm. A decrease capacity due to this effect. revealed dependence MWCNTs allows control...
The heat capacity at constant pressure CP of 1D-chains methane molecules adsorbed in the grooves on outer surface bundles closed single-walled nanotubes was measured temperature range from 2 to 60 K for first time. behavior dependence below 12 indicates presence a Schottky-type anomaly originated tunneling between lowest energy levels rotational spectra A, T, and E nuclear-spin species molecules. feature observed vicinity 14 is presumably caused by an orientational phase transition, which...
The low-temperature dependence of the heat capacity acrylonitrile-butadiene-styrene (ABS) polymer and its composite with thermally reduced graphene oxide was studied. existence a so-called “boson peak” characteristic orientational structural glasses demonstrated. boson peak appears in form local maximum curve displayed as C/T3 vs T at Tmax = 3.52 K. It found that for both ABS composite, well number other substances crystalline amorphous nature, manifestation anomaly has universal character...
Thermal stability and the kinetics of thermal decomposition thermally reduced graphene oxide (TRGO) treated by a pulsed high-frequency discharge in hydrogen atmosphere have been studied. The modified Hummers method was used for obtaining initial graphite from powder. exfoliation powder has done vacuum conditions with heating rate 5–7 degrees per minute to temperature 300 °С. TRGO partial hydrogenation (chemical addition atomic hydrogen) that leads structural changes carbon planes formation...
Correlation between thermal expansions $\beta(T)$ and heat capacity $C(T)$ of atomic molecular crystals, amorphous materials with a structural disorder, carbon nanomaterials (fullerite C$_{60}$, bundles SWCNTs single-walled nanotubes) was analyzed. The influence the contribution to coefficient linear expansion $\alpha_\textrm{Xe}(T)$ Xe atoms adsorbed on is considered. proportional correlation found normalized gas constant $C_\textrm{Xe}(T)/R$ bundles. $(\beta/\beta^*) \sim (C_\textrm{V}/R)$...
The nature of the linear term in heat capacity fullerite C60 has been investigated. low-temperature dependence sound velocity determined from data at temperatures below 4 K. A model dynamic configuration excitations (DCE) is proposed to describe contribution and calculate velocity. It shown that this model, apparently, adequately describes dynamics cluster formations short-range order by taking into account both atomic electronic subsystems. In framework it low-energy tunnel states are...
Possible changes in the temperature dependence of coefficient thermal conductivity hydroxyapatite (HA) composite with multi-walled carbon nanotubes (MWCNTs) small amounts MWCNTs additives (0.5 wt%) were analyzed comparison HA matrix without additives. It was found that can contribute to increase coefficient. The magnitude effect increasing varies from relatively values (about 1%) a significant up ∼ 20 times depending on interaction at HA–MWCNTs interface and degree homogeneity distribution...
The heat capacity of the interstitial solid solution (CH4)0.4C60 has been investigated in temperature interval 1.4–120 K. contribution CH4 molecules to separated. contributions and CD4 solutions (CH4)0.40C60 (CD4)0.40C60 have compared. It is found that above 90 K character rotational motion changes from libration hindered rotation. In 14–35 capacities are satisfactorily described by translational vibrations, as well tunnel rotation for equilibrium distribution nuclear spin species. isotope...
The fracture toughness coefficient Kc of the composite ceramics for medical applications based on hydroxy-apatite (HA) with additives multi-walled carbon nanotubes (MWCNTs) were investigated. Sintering composites was carried out at a temperature 1100°C in an argon atmosphere. rate heating up to sintering 20 K/min. HA is bioactive matrix, and MWCNTs used purpose increasing Kc. Nanoindentation tests using microhardness tester Affri DM8 Vickers pyramid-shaped diamond indenter under load 4.9 N....