Highly filled powder composites based on Al2O3 particles with a two-layer coating of ultra-high molecular weight polyethylene and low molecular weight polyethylene (Al2O3/UHMWPE/PE) were obtained by polymerization filling (in-situ) by successive two-stage polymerization, with a single-layer coating of ultra-high molecular weight polyethylene (Al2O3/UHMWPE) and low molecular weight polyethylene (Al2O3/PE) in a one-step process for 3D printing applications by selective laser sintering. Al2O3 corundum spheres with an average particle size of 20 μm were used as a filler, which provided the composite particles with a spherical shape and the necessary fluidity in the printer chamber. The melting temperature of nascent composites is higher than after melting, which widens the “sintering window,” and is important for 3D printing by means of selective laser sintering. The dynamic loss modulus in the α-relaxation region, which characterizes the mobility of polymer chains in the intercrystalline (amorphous) layer, is higher for Al2O3/UHMWPE/PE composites than for Al2O3/UHMWPE, their plasticity under uniaxial tension has also increased. The heat resistance of the synthesized composites, estimated by the method of dynamic mechanical analysis, is 20–33°C higher than that of ultrahigh molecular weight polyethylene. The content of the filler, the arrangement of polymer layers on the surface of the filler particles, and their composition affect the strength properties and the nature of the deformation of composites under uniaxial tension. The resulting composites with a filling of 10 and 30 vol

На данный момент актуальны исследования по созданию полимерных материалов являющимися сырьем для разнообразных аддитивных методов изготовления изделия, обладающих, при этом, такими электрофизическими свойствами как поглощение и отражение электромагнитного излучения различного диапазона или обладающих электропроводностью, достаточной, например, для отвода статического электричества.

Уважаемые коллеги!Благодарим Вас за проявленный интерес к Четвертой российской конференции «Графен: молекула и 2D кристалл» и желание принять участие в её работе.Конференция проходит в научно-образовательном центре города Новосибирска -Академгородке.Мероприятие посвящено актуальным направлениям исследований и разработок в области углеродных и низкоразмерных материалов.Проведение конференции поможет координации усилий ученых в решении современных проблем материаловедения и привлечению молодых исследователей для решения актуальных научных задач.Оргкомитет выражает особую благодарность НГУ, Центру компетенций НТИ «Моделирование и разработка новых функциональных материалов с заданными свойствами», компаниям «Диаэм», «НТ-МДТ Спектрум Инструментс» и корпорации "Графеновая Долина" за финансовую поддержку и журналам Аналитика, Наноиндустрия и РЭНСИТ за информационную поддержку.Искренне надеемся, что пребывание в Новосибирском Академгородке и в стенах Новосибирского государственного университета оставит множество положительных эмоций и

Composites with a two-layer coating consisting of ultra-high molecular weight polyethylene and a lower molecular weight high-density polyethylene are synthesized by the sequential two-step polymerization of ethylene on the surface of catalyst-activated Al2O3 particles to modify the properties of composite materials with the ultra-high molecular weight polyethylene matrix. The pressed specimens of the composites with the two-layer coating are characterized by the uniform distribution of components. The effect of composition of polymer coating of Al2O3 particles on the thermophysical and rheological properties of composite reactor powders and the deformation–strength properties of pressed specimens is studied. In nascent composite particles with the two-layer coating, the morphology of outer polymer layers is different and depends on the polymer type. The creation of two-layer coatings with the outer layer of a lower molecular weight polyethylene on filler particles renders it possible to realize the melt flowability of the composites at certain component ratios, while preserving deformation–strength characteristics at a high level. The proposed polymerization technique shows promise for development of ultra-high molecular weight polyethylene composite powders with the desired morphology and rheological characteristics suitable for selective laser sintering 3D printing. All synthesized composite powders based on Al2O3 spherical particles with one- and two-layer polymer coatings have shape close to spherical, repeating the shape of filler particles. In terms of rheological characteristics, they meet the requirements of selective laser sintering 3D printing and have free flowability, and the material of parts printed by this technology does not suffer from warping and shrinkage.

Уважаемые коллеги!Благодарим Вас за проявленный интерес к Четвертой российской конференции «Графен: молекула и 2D кристалл» и желание принять участие в её работе.Конференция проходит в научно-образовательном центре города Новосибирска -Академгородке.Мероприятие посвящено актуальным направлениям исследований и разработок в области углеродных и низкоразмерных материалов.Проведение конференции поможет координации усилий ученых в решении современных проблем материаловедения и привлечению молодых исследователей для решения актуальных научных задач.Оргкомитет выражает особую благодарность НГУ, Центру компетенций НТИ «Моделирование и разработка новых функциональных материалов с заданными свойствами», компаниям «Диаэм», «НТ-МДТ Спектрум Инструментс» и корпорации "Графеновая Долина" за финансовую поддержку и журналам Аналитика, Наноиндустрия и РЭНСИТ за информационную поддержку.Искренне надеемся, что пребывание в Новосибирском Академгородке и в стенах Новосибирского государственного университета оставит множество положительных эмоций и

Уважаемые коллеги!Благодарим Вас за проявленный интерес к Четвертой российской конференции «Графен: молекула и 2D кристалл» и желание принять участие в её работе.Конференция проходит в научно-образовательном центре города Новосибирска -Академгородке.Мероприятие посвящено актуальным направлениям исследований и разработок в области углеродных и низкоразмерных материалов.Проведение конференции поможет координации усилий ученых в решении современных проблем материаловедения и привлечению молодых исследователей для решения актуальных научных задач.Оргкомитет выражает особую благодарность НГУ, Центру компетенций НТИ «Моделирование и разработка новых функциональных материалов с заданными свойствами», компаниям «Диаэм», «НТ-МДТ Спектрум Инструментс» и корпорации "Графеновая Долина" за финансовую поддержку и журналам Аналитика, Наноиндустрия и РЭНСИТ за информационную поддержку.Искренне надеемся, что пребывание в Новосибирском Академгородке и в стенах Новосибирского государственного университета оставит множество положительных эмоций и

Highly filled (up to 90 vol %) UHMWPE composites with Al of controlled dispersed composition (micro-, nanoparticles, and their mixtures) were obtained by the polymerization filling method. The use of a mixture of micro- and nano Al particles predominantly containing micron-sized particles allowed us to achieve a denser packing of heat-conductive particles in the polymer matrix and create more efficient heat-conductive paths in compressed specimens, in comparison with the composites containing only the micro- or nano Al particles. The thermal conductivity achieved with a mixture of nano/micro aluminum particles in the ratio 30/70 was 9.7 W/mK at 82 vol % degree of filling. The enhanced thermal conductivity of the materials goes together with high electrical insulating properties (σdc not higher than 10–9 S/cm) due to the presence on Al particles, in addition to thin oxide coating, also a coating of UHMWPE. The high thermal conductivity and electrical insulating properties of the obtained UHMWPE composites are combined with high strength properties under compression. At total aluminum concentrations up to 80 vol %, the pressed specimens do not collapse under compression, and have significantly enhanced modulus of elasticity under compression and strength at the yield point compared to UHMWPE. It is the combination of the UHMWPE matrix and the polymerization method for incorporation of fillers into it, including nanosized ones, that makes it possible to obtain highly filled composite materials with a high level of functional and mechanical properties.

The electrical and heat conduction properties of polymerization-filled composites based on ultra-high-molecular-weight polyethylene and differently proportioned mixtures of aluminum micro- and nanoparticles coated with oxide layers of various thicknesses have been studied. The composite composition optimal for producing heat-conductive dielectric materials for heat sinks in electronics has been determined. By analyzing the frequency and concentration dependences of the electrical conductivity of the studied composites and the concentration dependences of their thermal conductivity, conclusions were drawn on the charge-transfer mechanisms and the structure of the clusters of the filler.

The electrical properties of R-phycoerythrin modified with Ag0 nanoparticles (Ag0 • R-PE) as a candidate material for biosensors were studied were studied. Modification was ensured by a known procedure: synthesis of Ag0 nanoparticles in R-phycoerythrin channels through the addition of AgNO3 to an aqueous R-phycoerythrin solution. According to electron microscopy results, the Ag0 • R-PE contains predominantly elongated Ag0 nanoparticles 6.2 ± 0.5 nm in length, which form structures similar to rows 20–60 nm in length. The electrical conductivity, dielectric permittivity, and dielectric loss of the Ag0 • R-PE have been measured in the frequency range from 0.01 Hz to 1 MHz. Filling the channels in R-phycoerythrin molecules with Ag0 nanoparticles has been shown to increase the alternating current electrical conductivity and dielectric loss of the material at low frequencies by more than 200 times and its dielectric permittivity by 40 times. Ag0 nanoparticles increase the direct current conductivity of R-phycoerythrin from 5 × 10–14 to 2.5 × 10–11 S/cm. The electrical properties of Ag • R-PE are comparable to those of conductive polymer composites that contain metallic nanowires and are used in designing multifunctional films and smart materials.

An approach was described to obtaining polymer composites with segregated structure that have high electrical conductivity at low concentrations of an electrically conductive filler. According to this approach, thin layers of electrically nonconductive nanodispersed graphene oxide are applied to the surface of polymer particles and conduction is produced by heat and chemical treatments. Hot pressing of the modified powder leads to combination of layers of the graphene-like filler to form a single electrically conductive network. For the first time, reduction of graphene oxide on the surface of polymer particles with hydrazine vapor at room temperature was performed. Comparison of the electrical conductivities of composites obtained by the thermal and chemical methods of graphene oxide reduction showed that the chemical reduction method gives composites with higher conductivities than the thermal method does. The maximum conductivity (0.5 S/m) was reached in a composite containing 0.6% chemically reduced graphene oxide.

Glassy PMMA samples are plastically deformed at room temperature in the uniaxial compression regime to residual strains of e res = 25%. Dielectric spectra of the initial and deformed samples are recorded via the method of broadband dielectric spectroscopy in the frequency range f = (5 × 10−4) − 107 Hz. The results are compared with the dynamic mechanical spectra of samples deformed under the same conditions. Dielectric and mechanical spectra are noticeably distorted by deformation. As a result, dielectric permittivity ɛ′ increases, shear modulus G′ decreases, and the intensity of dielectric β losses slightly increases, while dielectric and mechanical α losses increase appreciably. In addition, the “anomaly” of total dielectric Δɛtot and total mechanical ΔG tot dispersions (Δɛtot = ɛ0 − ɛ∞ ≈ Δɛα + Δɛβ and ΔG tot = G 0 − G ∞ ≈ ΔG α + ΔG β) occurs, that is, the polymer is transformed from the state with Δɛα ≪ Δɛβ and ΔG α < ΔG β into the state with Δɛα > Δɛβ and ΔG α > ΔG β. The described phenomenon is related to a strong gain in α dielectric and mechanical losses in the deformed material. It is found that α losses increase owing to an anelastic deformation component arising during glass loading. This component is responsible for an increase in the internal energy of the glass during its anelastic deformation. Possible causes of the observed effects are discussed.

The experimental data on high-temperature dielectric relaxation α c in linear PE samples with different thermal prehistories (slow cooling, quenching, and annealing) are described. The measurements are conducted at temperatures ranging from 0 to 80°C. Dielectric losses are measured with a high accuracy at frequencies varying from 10 −2 to 10–10 6 Hz. These dielectric measurements allow one to reveal changes in the frequency dependence of losses with temperature. This effect of the thermal prehistory of the sample and applied stress is explained within the framework of the molecular model of chain diffusion between crystalline and amorphous phases in PE.

Variations in the dc and ac conductivities of schungite-containing compositions based on polypropylene-high-density polyethylene (PP-PE) blends were studied depending on the composition of the polymeric blend, the volume concentration of the filler, and the order of the introduction of the composition components during the preparation of compositions. It was shown that the conductivities of the compositions could depend on the order of the introduction of the components. The structure of initial and schungite-containing PP-PE blends of different compositions was studied by atomic-force microscopy. It was shown that the structure of the compositions depended on the composition of the initial PP-PE blends and the order of the introduction of the components into schungite-filled PP-PE compositions.

The electric properties of polymeric composites with a shungite filler are studied. The changes in the conductivity on the filler concentration, electric field frequency, temperature, and time of exposure to elevated temperatures are investigated. The properties of the studied materials are compared with the characteristics of composites based on traditional carbon fillers (carbon black, graphite). Shungites may turn out to be more promising fillers than traditional ones for producing materials with a direct-current conductivity of 10(-11) to 10(-3) (Omega cm)(-1), because shungite-containing composites are characterized by a higher reproducibility and a greater thermal stability of the electrical properties.