Modern methods of obtaining few-layer graphene structures by the method of electrochemical
exfoliation of graphite
E. S. Bakunin, E. Yu. Obraztsova, A. V. Rukhov
An overview of the methods for obtaining few-layer graphene structures (FLG) by electrochemical exfoliation of graphite in aqueous solutions of inorganic substances and ionic liquids is reviewed. The proposed mechanisms of processes are considered, as well as the effect of electrolysis regimes on the qualitative characteristics of the product obtained. It is shown that the method of electrochemical exfoliation of graphite is based on the destruction of graphite-containing materials in solutions of various substances containing ions capable of undergoing intercalation into graphite under the influence of electric current. It is established that in general the procedure of electrochemical exfoliation of graphite contains two stages, the first of which is the intercalation of ions from the electrolyte solution into the space between the graphene sheets with the formation of covalent or ionic bonds, and the second involves the exfoliation of the material as a result of the electrochemical reaction. So initially a potential, usually smaller than the working one, is applied to the electrode to be destroyed, to effect a good wetting of the surface and preliminary intercalation of the graphite. In the next stage, the main stage of obtaining FLG, characterized by superposition of the operating voltage, begins. Then, as a rule, surface-active substances are introduced into the solution, which facilitate exfoliation, as well as reduce the agglomeration of the obtained suspensions of FLG. The stages of separation and purification of the product are described.
Key words: few-layer graphene structures, graphite, electrochemical exfoliation.
Bakunin Evgeniy — Tambov State Technical University (Tambov, 392000, Sovetskaya st., 106), PhD, assistant of the department, specialist in the field of carbon nanomaterials catalyst synthesis and electrochemical technology. E-mail: jack1400@yandex.ru.
Obraztsova Elena — Tambov State Technical University (Tambov, 392000, Sovetskaya st., 106), PhD, associate professor of the department, specialist in the field of electrochemical technology. E-mail: nikif83@mail.ru.
Rukhov Artem — Tambov State Technical University (Tambov, 392000, Sovetskaya st., 106), Dr Sci (Eng), associate professor, head of the department, specialist in the field of synthesis of carbon nanostructured materials. E-mail: artem1@inbox.ru.
Reference citing
Bakunin E. S., Obraztsova E. Yu., Rukhov A. V. Sovremennye sposoby polucheniya maloslojnyh grafenovyh struktur metodom ehlektrohimicheskoj ehksfoliacii grafita [Modern methods of obtaining few-layer graphene structures by the method of electrochemical exfoliation of graphite]. Perspektivnye Materialy — Advanced Materials (in Russ), 2018, no. 7, pp. 5 – 15.
Functional properties improvement of medical stainless steel surface by helium, argon and silver ions treatment
I. V. Perinskaya, I. V. Rodionov, L. E. Kuts
Investigations of the carbon film synthesis on the surface of the steel orthopedic structures obtained by argon ions implantation (accelerating voltage Uacc = 40 – 130 kV and dose range f = (1,25 – 3,1)·1016 ion/cm2) in a carbon dioxide medium has been studied. It is shown that Ar+ ions implantation in CO2 environment leads to the significant increase of microhardness of medical steel surface (up to 31 GPA). The method of ion-beam modification of the carbon diamond-like film by silver ions implantation (accelerating voltage 50 kV and dose range 1.2∙1016 – 1,8∙1016 ion/cm2) to impart antimicrobial surface properties has been proposed. The studies in vivo proved that the steel implants modified by developed ion-beam method, are efficiently taken roots in the bone tissue without inflammatory processes in the surrounding biostructures.
Keywords: medical stainless steel, implants, ion beam treatment, blistering, pore formation, carbon diamond-like film.
Perinskaya Irina — Yuri Gagarin State Technical University of Saratov (Saratov, 410054, Polytechniсheskaya ul., 77), PhD (eng), specialist in the field of technology for modifying materials by ion-beam method. E-mail: perinskayaiv@mail.ru.
Rodionov Igor — Yuri Gagarin State Technical University of Saratov (Saratov, 410054, Polytechniсheskaya ul., 77), Dr Sci (eng), specialist in the field of innovative technological processes for modifying metal surfaces, studying the phase-structural state and corrosive behavior of materials, studying the features and establishing patterns of changes in the functional properties of metals and alloys depending on the type of technological impact. E-mail: iv.rodionov@mail.ru@mail.ru.
Kuts Lyubov — Yuri Gagarin State Technical University of Saratov (Saratov, 410054, Polytechniсheskaya ul., 77), PhD (eng), specialist in the field of innovative technological processes for modifying metal surfaces. E-mail: kuts70@yandex.ru.
Reference citing
Perinskaya I. V., Rodionov I. V., Kuts L. E. Povyshenie funkcional'nyh svojstv poverhnosti medicinskoj hromonikelevoj stali ionno-luchevoj obrabotkoj ionami geliya, argona i serebra [Functional properties improvement of medical stainless steel surface by helium, argon and silver ions treatment]. Perspektivnye Materialy — Advanced Materials (in Russ), 2018, no. 7, pp. 16 – 25.
Investigation of α-tricalcium phosphate based brushite cement and its composite with polylactic framework
A. V. Knotko, P. V. Evdokimov, I. V. Fadeyeva, A. S. Fomin,
S. M. Barinov, V. A. Volchenkova, A. A. Fomina
The brushite cement based on alpha-tricalcium phosphate (α-TCP) and its composite with polylactide frame (PL) with a Kelvin structure were developed. The composites were obtained by filling the PL frame with liquid cement paste by extrusion. The 30 % aqueous solution of magnesium dihydrogenphosphate was used as a cement liquid. The cement phase composition was studied before soaking in physiological solution: the main phases are dicalcium phosphate dihydrate, tricalciumphosphate and amorphous calcium phosphate. It was found that magnesium does not form a separate phase, but probably enters the crystal lattice of DCPD. During soaking the cement in a physiological solution, two processes occur simultaneously-the release of calcium ions into the solution due to dissolution DCPD and the precipitation of calcium ions from the solution on the cement surface in the form of apatite, which is confirmed by the data of XRD and microstructure studies. After incubation in physiological solution apatite phase becomes the main phase, the contents DCPD decreases, which is related to transformation DCPD in the apatite phase. Solubility was studied in physiological solution containing TRIS-buffer. In the absence of a buffer, the pH of the solution increased and as a result solubility of the composite increased too. In the presence of buffer solubility of cement and composite varied only slightly.
Keywords: brushite cement, reinforcement, 3D printing, polylactic acid, architecture Kelvin, the solubility.
Knotko Alexander — M.V. Lomonosov Moscow State University (Lomonosov MSU, GSP-1, Leninskie Gory, Moscow, 119234, Russia), Dr Sci, dean deputy of material science department, specialist in the field of inorganic chemistry. E-mail: alknt@mail.ru.
Evdokimov Pavel — M.V. Lomonosov Moscow State University (Lomonosov MSU, GSP-1, Leninskie Gory, Moscow, 119234, Russia), PhD, junior researcher, chemical department, specialist in the field of material science. E-mail: pavel.evdokimov@gmail.com.
Fadeeva Inna — Baikov Institute of Metallurgy and Materials Science, RAS (119334, Leninsky avenue, 49, Moscow, Russia), leading researcher, PhD, specialist in the field of inorganic chemistry and materials in medicine. E-mail: fadeeva_inna@mail.ru.
Fomin Alexander — Baikov Institute of Metallurgy and Materials Science, RAS (119334, Leninsky avenue, 49, Moscow, Russia), senior researcher, PhD, specialist in the field of inorganic chemistry and materials in medicine. E-mail: alex_f81@mail.ru.
Barinov Sergey — Baikov Institute of Metallurgy and Materials Science, RAS (119334, Leninsky avenue, 49, Moscow, Russia), corr.-member of RAS, Dr Sci, chief researcher, specialist in the field of materials in medicine. E-mail: barinov_s@mail.ru.
Volchenkova Valentina — Baikov Institute of Metallurgy and Materials Science, RAS (119334, Leninsky avenue, 49, Moscow, Russia), leading researcher, PhD, specialist in the field of analytical chemistry.
Fomina Alla — Baikov Institute of Metallurgy and Materials Science, RAS (119334, Leninsky avenue, 49, Moscow, Russia), researcher, specialist in the field of analytical chemistry.
Reference citing
Knotko A. V., Evdokimov P. V., Fadeyeva I. V., Fomin A. S., Barinov S. M., Volchenkova V. A., Fomina A. A. Issledovanie brushitovogo cementa na osnove al'fa-trikal'cijfosfata i ego kompozita s polilaktidnym karkasom [Investigation of a-tricalcium phosphate based brushite cement and its composite with polylactic framework]. Perspektivnye Materialy — Advanced Materials (in Russ), 2018, no. 7, pp. 26 – 32.
Thermoelastoplasts based on the mixture of thermoplastic polyolefins and butyl rubber
Z. N. Guseynova, N. T. Kakhramanov, B. A. Mamedov,
V. S. Osipchik, U. M. Mammadli
This paper presents the results of a study of the influence of the concentration of butyl rubber and dicumyl peroxide on the strength and thermophysical properties of polymer mixtures based on thermoplastic polyolefins. The principal possibility of obtaining of thermoplastic elastomers with predetermined physical and mechanical characteristics are shown. The concentration of butyl rubber is varied from 0 to 50 wt. %, and the dicumyl peroxide from 0.5 to 2.0 wt. %. It is experimentally established that in the process of studying the deformation-strength properties for thermoplastic polyolefins, the appearance of tensile yield stress and ultimate tensile stress is typical. However, as the concentration of butyl rubber in the thermoplastic composition increases, the difference between the tensile yield stress and ultimate tensile stress is sharply reduced. And, when the difference between these strength parameters completely disappears, the polymer composition begins to exhibit the properties of the thermoplastic elastomer. The additional introduction of crosslinking agent - dicumyl peroxide into the composition of polymer mixtures promotes the appearance of the rubber-like plateau on the thermomechanical curves, which, as is well known, is characteristic for vulcanized rubbers. The most optimal concentrations of dicumyl peroxide and butyl rubber are determined, as a result of which the highest physicomechanical properties in polymer compositions are achieved. An interpretation of the observed regularities in the change of physicomechanical and physicochemical properties of polymer composite materials is given.
Keywords: butyl rubber, dicumyl peroxide, ultimate tensile stress, interfacial region, crystallinity.
Guseynova Zulphira Neymat — Institute of Polymer Materials of the National Academy of Sciences of Azerbaijan (Azerbaijan, Sumgayit, AZ 5004, S.Vurgun Str, 124), PhD (Chem), leading researcher, specialist in the field of obtaining and studying the structure and properties of composite materials on the basis of mixture of different types of polymer systems.
Kakhramanov Najaf Tofig — Institute of Polymer Materials of the National Academy of Sciences of Azerbaijan (Azerbaijan, Sumgayit, AZ 5004, S.Vurgun Str, 124), DrSci (chem.), professor, head of laboratory, specialist in the field of chemical and mechano-chemical modification of polymers, research and processing of nanocomposites, research of the relationship between the structure and properties of composite materials. E-mail: najaf1946@rambler.ru.
Mammadov Bakhtiyar Azhdar — Institute of Polymer Materials of the National Academy of Sciences of Azerbaijan (Azerbaijan, Sumgayit, AZ 5004, S.Vurgun Str, 124), Dr Sci (chem.), professor, director of the Institute, corresponding member of the National Academy of Sciences of Azerbaijan, specialist in the field of synthesis, modification and research of the structure and properties of polymer materials.
Osipchik Vladimir Semenovich — Dmitry Mendeleev University of Chemical Technology of Russia (Miusskaya sq., 9, 125047 Moscow, Russia), DrSci (eng), professor, deputy head of the department, leading specialist in the field of chemical and mechano-chemical modification of polymers, technologies for processing polymer systems, establishing the relationship between the structure and properties of polymer composites. E-mail: vosip@muctr.ru.
Mammadli Ulviya Mamedgusein — Institute of Polymer Materials of the National Academy of Sciences of Azerbaijan (Azerbaijan, Sumgayit, AZ 5004, S.Vurgun Str, 124), PhD (Chem), associate professor, senior researcher, specialist in the field of synthesis and research of the structure and properties of polymers, polymer composite systems.
Reference citing
Guseynova Z. N., Kakhramanov N. T., Mamedov B. A., Osipchik V. S., Mammadli U. M. Termoehlastoplasty na osnove termoplastichnyh poliolefinov i butilkauchuka [Thermoelastoplasts based on the mixture of thermoplastic polyolefins and butyl rubber]. Perspektivnye Materialy — Advanced Materials (in Russ), 2018, no. 7, pp. 33 – 42.
Сomposite soft-magnetic material
G. A. Govor, A. O. Larin
Research of the main magnetic characteristics of the developed composite magnetic material based on iron powder ASC100.29 and composite magnetic materials using various iron powders was performed in comparison with the analogous parameters for electrical steel 3412 (E320). Shown, that the magnetic induction of the developed composite material in fields up to H = 5 – 6 kA/m is inferior to the value of induction of electrical steel, and at higher fields it exceeds the parameters for electrical steel. The magnetic induction at H = 25 kA/m for a composite magnetic material is Bm = 1,95 – 2,0 T, and for a steel in the same field Bm = 1.84 T for the same density of samples ρ = 7.7 g/cm3. Investigations of the relative losses on the remagnetization of composite materials based on iron powders sprayed with air and water, which showed some advantage of the purer iron powders obtained by the water-spray method, were carried out. Low hysteresis losses of the composite magnetic material make it possible to use it in electric machines of increased specific power, in particular with a high rotational speed, where electrical steels have large losses.
Keywords: composite material, soft-magnetic material, magnetic properties, hysteresis losses.
Govor Gennadii — State Scientific and Production Association “Scientific and Practical Center of the National Academy of Sciences of Belarus for Materials Science” (Minsk, 220072, P. Brovki str., 19), Dr Sci (Phys-Math), chief researcher, specialist in solid state physics. E-mail: govor@physics.by.
Larin Artem — State Scientific and Production Association “Scientific and Practical Center of the National Academy of Sciences of Belarus for Materials Science” (Minsk, 220072, P. Brovki str., 19), junior researcher. E-mail: larin@physics.by.
Reference citing
Govor G. A., Larin A. O. Magnitnye svojstva nizkochastotnogo kompozicionnogo magnitno-myagkogo materiala [Сomposite soft-magnetic material]. Perspektivnye Materialy — Advanced Materials (in Russ), 2018, no. 7, pp. 43 – 48.
Combined effect of sever plastic deformation
and cold rolling on mechanical properties
of the Al – Mg2Si system alloys
N. R. Bochvar, L. L. Rokhlin, I. E. Tarytina
Investigations of the strength properties and microstructure of the Al – Mg – Si alloys disposed along the quasi-binary Al – Mg2Si section were performed. The alloys contained small quantities of scandium with zirconium and scandium with hafnium. They were quenched and underwent then the equal channel angular pressing and cold rolling followed by artificial ageing. It was established, that amongst the alloys containing 1.4 % Mg2Si with Sc+Zr or Sc+Hf the highest strength properties after equal channel angular pressing and cold rolling were achieved in those containing scandium together with zirconium. The lowest strength properties were observed in the alloys containing both scandium together with zirconium and hafnium or without all of the transition metals after only equal channel angular pressing. The cold rolling after quenching and equal channel angular pressing promotes increase of the strength properties of the alloys after ageing at 170 °C, as compare with the alloys aged at the same temperature only after equal channel angular pressing or only after cold rolling. Investigation of the alloy microstructure indicated, that strengthening of the alloys after applied treatments was connected with aluminum crystal lattice distortions, which arisen as a result of cold rolling, equal channel angular pressing and ageing of them.
Key words: aluminium alloys, cold rolling, sever plastic deformation, strength properties, ageing.
Bochvar Nataliya — Baikov Institute of Metallurgy and Materials Science of RAS(49, Leninsky prospect, Moscow 119334, Russia), PhD (eng), leading searcher, specialist on the non-ferrous and light metals science. E-mail: bochvar@imet.ac.ru.
Rokhlin Lazar — Baikov Institute of Metallurgy and Materials Science RAS (49, Leninsky prospect, Moscow 119334, Russia), Dr Sci (eng), general researcher, specialist on the non-ferrous and light metals science.E-mail: rokhlin@imet.ac.ru.
Tarytina Irina — Baikov Institute of Metallurgy and Materials Science RAS (49, Leninsky prospect, Moscow 119334, Russia), searcher, specialist on the non-ferrous and light metals science, searcher, specialist on the non-ferrous and light metals science. E-mail:
tarytina@yandex.ru.
Reference citing
Bochvar N. R., Rokhlin L. L., Tarytina I. E. Sovmestnoe vliyanie intensivnoj plasticheskoj deformacii i holodnoj prokatki na mekhanicheskie svojstva alyuminievyh splavov na osnove sistemy Al – Mg2Si [Combined effect of sever plastic deformation and cold rolling on mechanical properties of the Al – Mg2Si system alloys]. Perspektivnye Materialy — Advanced Materials (in Russ), 2018, no. 7, pp. 49 – 56.
Structural state and corrosion resistance of plasma spray
coating from nickel alloy
Iu. A. Pustov, V. I. Kalita, A. A. Tursunbaeva, D. I. Komlev,
A. A. Radiuk, A. Iu. Ivannikov
Plasma spray coating from 12496-type nickel alloy with thickness about 400 mkm was deposited on St.3 carbon steel. Isothermal vacuum (13 Pa) annealing at 800 °C during 3 hours shown that annealing leads to formation of an amorphous-crystalline structure of the coating and decrease internal porosity. X-ray analysis, SEM microscopy, chronopotentiometry, potentiodynamic voltammetry and gravimetry methods were used for study structure, electrochemical behavior and corrosion resistance of samples. The study was carried out in neutral (3 % NaCl) and acidic (0.5 N HNO3) media. It is established that the difference in the corrosion-electrochemical behavior of annealed (800 °C for 3 h) alloy samples in the cast state and in the plasma coating state and having the same phase composition is mainly due to the specific morphological structure of the surface coating regions. The presence of surface pores and caverns (in the absence of through porosity) leads to the appearance of local corrosion cells. This is due to the restriction of the access of the depolarizer (oxygen or hydrogen) to the apex of cavities or pores, the cathodic process is inhibited and, as a consequence, the electrode potential of the metal at the apex of the caverns is displaced to the negative side, which facilitates the anodic process. The corrosion rate of annealed samples of the plasma coating is 5 – 6 times higher than the corrosion rate of annealed cast alloy samples. Differences in electrochemical behavior and corrosion resistance are almost completely eliminated by impregnating the coating with a hydrophobizing liquid Anacrol 2501.
Keywords: plasma spray coating, nickel alloy 12496-type, structure, isothermal annealing, surface morphology of coatings, electrochemical behavior, corrosion resistance, hydrophobizing liquid.
Pustov Iurii — National Research Technological University MISiS (Moscow, 119049, Leninsky Prospect, 4), Ph.D., assistant professor, specialist in the field of structure and corrosion resistance of alloys.
Kalita Vasilii — Baikov Institute of Metallurgy and Materials Science of RAS (Moscow, 119334, Leninsky Prospect, 49), Dr Sci (eng), chief scientist, head of laboratory, specialist in the field of plasma spraying. E-mail: vkalita@imet.ac.ru.
Tursunbaeva Asel` — National Research Technological University MISiS (Moscow, 119049, Leninsky Prospect, 4), graduate student, specialist in the field of structure and corrosion resistance of alloys. E-mail: aseltu5@gmail.com.
Komlev Dmitrii — Baikov Institute of Metallurgy and Materials Science of RAS (Moscow, 119334, Leninsky Prospect, 49), Ph.D., Leading Researcher, a specialist in the field of plasma spraying. E-mail: imet-lab25@yandex.ru.
Radiuk Aleksei — Baikov Institute of Metallurgy and Materials Science of RAS (Moscow, 119334, Leninsky Prospect, 49), junior researcher, specialist in the field of plasma spraying. E-mail: imet-lab25@yandex.ru.
Ivannikov Alexander — Baikov Institute of Metallurgy and Materials Science of RAS (Moscow, 119334, Leninsky Prospect, 49), PhD, senior researcher, specialist in the field of plasma spraying. E-mail: imet-lab25@yandex.ru.
Reference citing
Pustov Iu. A., Kalita V. I., Tursunbaeva A. A., Komlev D. I., Radiuk A. A., Ivannikov A. Iu. Strukturnoe sostoyanie i korrozionnaya stojkost' plazmennogo pokrytiya iz nikelevogo splava [Structural state and corrosion resistance of plasma spray coating from nickel alloy]. Perspektivnye Materialy — Advanced Materials (in Russ), 2018, no. 7, pp. 57 – 66.
Effect of temperature on annealing products
of synthesized opal matrix
A. A. Dyshin, O. V. Eliseeva, G. V. Bondarenko, M. G. Kiselev
The synthesis of opal matrix by the sol-gel method and the α-cristobalite production from opal matrix by the high-temperature annealing method are describes. Receiving conditions for the preparation of synthetic opal matrices by the hydrolysis of tetraethoxysilane in a binary ethanol-water solvent using an ammonia solution as a catalyst and concentration of reactants are considered in details. Silica particles were obtained by multistage growth to the required size by the addition of tetraethoxysilane to the reaction mixture. The temperature regime of siliceous xerogel drying is proposed for obtaining of porous matrices for further annealing and obtaining high-purity α-cristobalite. Structural changes, such as an increase in the density of matrices, their hardening and porosity changes occurring in matrices as a function of temperature are described. Upon annealing up to a temperature of 1100 °C, open-pore matrices consisting of amorphous silica are obtained. These matrices can later be used to impregnate different compositions in order to obtain various kinds of sensors, composite materials and inverted matrices. Transition of siliceous xerogel from amorphous to crystalline state to produce a sample of low-temperature α-cristobalite with an admixture of α-tridymite as a result of drying and annealing at a temperature of 1300 °C is shown. Further annealing of this sample at a temperature of 1650 °C results in a transparent non-porous sample of a-cristobalite. All studies where carried out by electron microscopy, Raman spectroscopy, and X-ray diffraction analysis.
Keywords: α-cristobalite, synthetic opals, sol-gel method, Raman spectroscopy, X-ray diffraction analysis, SEM.
Dyshin Alexey — G.A. Krestov Institute of Solution Chemistry of Russian Academy of Science (Akademicheskaya St., 1, Ivanovo, 153045, Russia), PhD (chem), researcher, specialist in physical chemistry of solutions, synthesis and research of opal matrices and composite materials for various purposes, IR and Raman spectroscopy. E-mail: aad@isc-ras.ru.
Eliseeva Olga — G.A. Krestov Institute of Solution Chemistry of Russian Academy of Science (Akademicheskaya St., 1, Ivanovo, 153045, Russia), PhD (chem), senior researcher, specialist in physical chemistry of solutions, synthesis and research of opal matrices and polymeric materials, and composites of various purposes on their basis. E-mail: eov@isc-ras.ru.
Bondarenko Galina — Institute of Experimental Mineralogy of the Russian Academy of Science (Akademika Osip’iana St., 4, Chernogolovka, Moscow region, 142432, Russia, Russia), PhD (phys-math), head of laboratory of physical research, specialist in supercritical fluid technologies, IR and Raman spectroscopy under normal and supercritical state parameters. E-mail: bond@iem.ac.ru.
Kiselev Michail — G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Science (Akademicheskaya St., 1, Ivanovo, 153045, Russia), Dr Sci (chem), Director of the Institute, head of the laboratory NMR-spectroscopy and numerical investigation methods of liquids, specialist in physical chemistry of solutions, supercritical fluid technologies, IR and Raman spectroscopy, molecular dynamics modeling and quantum chemistry. E-mail: mgk@isc-ras.ru.
Reference citing
Dyshin A. A., Eliseeva O. V., Bondarenko G. V., Kiselev M. G. Vliyanie temperatury na produkty otzhiga sintezirovannyh opalovyh matric [Effect of temperature on annealing products of synthesized opal matrix]. Perspektivnye Materialy — Advanced Materials (in Russ), 2018, no. 7, pp. 67 – 75.
