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Том 473, № 1 (2017)
- Год: 2017
- Статей: 5
- URL: https://journals.rcsi.science/0012-5016/issue/view/9211
Physical Chemistry
Molecular dynamics simulation of two-sided chemical modification of carbon nanoribbons on a solid substrate
Аннотация
The position of a graphene nanoribbon on a solid substrate allows the chemical modification of only one of the nanoribbon sides. A method was proposed that enables the chemical modification of the other side, too. It was numerically modeled how a nanoribbon separated from a substrate rolls up into a roll and how the roll unrolls on a flat substrate. The dependences of the number of coils and the radii of rolls forming by hydrogenation on the nanoribbon length and width were determined.
37-40
Synthesis of platinum nanoparticles on substrates of various chemical natures using supercritical carbon dioxide
Аннотация
A method for synthesizing platinum nanoparticles on a dispersed substrate using supercritical carbon dioxide was applied on substrates of various chemical natures: silicon carbide, titanium nitride, and tin dioxide. On all the substrates, materials with narrow uniform platinum nanoparticle size distributions were obtained. The platinum nanoparticle size distribution on each of the substrates was studied. It was shown that the platinum particle sizes are within a narrow range with an average particle size of about 3 nm and scarcely dependent on the chemical nature of the substrate.
41-44
Radical cations in irradiated solid n-alkanes and polyethylene
Аннотация
The method of time-resolved magnetic field effect (TR MFE) in recombination fluorescence of spin-correlated radical ion pairs has been used to detect and identify radical cations generated at early stages after the pulse irradiation of polyethylene and tricosane. From analysis of TR MFE curves, the widths of unresolved EPR spectra of radical cations have been determined, and their g factors have been evaluated. The results have demonstrated that, as distinct from n-alkanes, primary radical cations in polyethylene are localized on chemical defects of the polymer chain in a time of about 1 ns or less.
45-48
Changes in the structure of cell wall polymers in thermomechanical treatment of highly lignified plant feedstock
Аннотация
The effect of mechanical treatment at various temperatures on structural changes in polymers contained in highly lignified plant feedstock was studied by the example of reed stems. The optimal conditions (about 10°C) of mechanical activation of plant feedstock were determined, under which its structure is disordered enough for subsequent enzymatic hydrolysis, but the lignin decomposition is prevented, and so is the formation of a layer of substances inhibiting enzymes on the surface of particles.
49-51
New polymer composites based on keratin and polyethylene
Аннотация
New biodegradable composites based on keratin and polyethylene have been produced under shear deformation. It has been demonstrated that the introduction of keratin leads to an increase in elastic modulus and to a decrease in ultimate tensile strength and elongation at break of the compositions. Elongation at break εb depends on the keratin dispersity; the highest εb values are observed for the compositions containing the smallest keratin particles. It has been shown that the compositions are susceptible to mold fungi; i.e., they are biodegradable.
52-53