Ultradispersed Diamond Research Articles

Increasing the Lifetime of Water Transportation Vehicles by Using Multifunctional Composites with a Polymer Matrix, Ultradisperse Diamond, and Discrete Fibrous Filler

Increasing the Lifetime of Water Transportation Vehicles by Using Multifunctional Composites with a Polymer Matrix, Ultradisperse Diamond, and Discrete Fibrous Filler

Structure formation of ultradispersed diamond by detonation synthesis

In the present work, we report on structure formation of ultradispersed diamond through detonation synthesis. In particular, based on the present data, we can state that ultradispersed diamond of detonation (UDD) synthesis is characterized by a rail substructure formation, which is typical for diamonds of dynamic and static synthesis formed from graphite by the martensitic mechanism. The formation of UDD is characterized by a two-stage process: the first stage is the formation of graphite from detonation products, and the second stage is the transformation of graphite into diamond by the martensitic mechanism. A microlamellar substructure in the rails of diamonds formed from the original graphite is due to the presence of basic packing defects that is characteristic for covalent crystals with a wurtzite lattice deformed at high pressures and temperatures typical for lonsdaleite. The presence of lonsdaleite in UDD also indicates its formation in the process of synthesis of diamond from graphite through the martensitic transformation.

Kinetic Laws of the Cathodic Deposition of a Tin–Bismuth Alloy and the Influence of Ultradispersed Diamonds

Kinetic Laws of the Cathodic Deposition of a Tin–Bismuth Alloy and the Influence of Ultradispersed Diamonds

Mechanism of incorporation of carbon nanomaterial particles in composite electrolytic metal coating

The problem of joint electrolytic deposition of metal ions and ultradispersed diamond particles into a metal matrix is formulated. The mathematical model describing the mechanism and kinetics of the cathodic process, the mass transfer of metal ions and carbon nanomaterial particles is developed. It has been established that transfer of particles of the dispersed phase occurs mainly not by the diffusion mechanism but under the influence of an electric field. Keywords: ultradispersed diamond particles, electrodeposition, composite electrolytic coatings.

A New Structure with Localized sp2 Bonding for Fivefold Twinning in Diamond.

Changes in atomic bonding configuration in carbon from sp3 to sp2 are known to exist in certain structural defects in diamond, such as twin boundaries, grain boundaries, and dislocations, which have a significant impact on many properties of diamond. In this work, the atomic structure of fivefold twinning in detonation synthesized ultra-dispersed diamonds is investigated using a combination of techniques, including spherical aberration-corrected high-resolution electron microscopy (HREM), HREM image simulations, and molecular mechanics (MM) calculations. The experimental HREM images reveal clearly that the fivefold twinning in diamond has two distinct structures. In addition to the concentric fivefold twins, where the core structure is the intersection of five {111} twinning boundaries, a new extended core structure with co-hybridization of bonding is identified and analyzed in fivefold twinning. The atomic structure forming these fivefold twinning boundaries and their respective core structures is proposed to involve both the tetrahedral sp3 and planar graphitic sp2 bonding configurations, in which a co-hybridized planar hexagon of carbon serves as a fundamental structural unit. The presence of this sp2 -bonded planar unit of hexagonal carbon rings in general grain boundaries is also discussed.

Вплив вибору марки ріжучих алмазів та концентрації УДПА у наповнювачі зв’язки на працездатність алмазних трубчастих свердл при обробці граніту та скла

The results of laboratory tests for drilling granite and window glass with diamond tube drills are given. The drills were made by the method of vacuum impregnation, developed at the Institute of Scientific Research of the National Academy of Sciences named after I. M. Frantsevich, and studied on a Sachsenwerk drilling machine (Dresden, Germany) in cold running water in order to prevent oxidation of diamonds and bonds due to their heating during work. The dependence of the efficiency of the drills on the content of very strong cutting diamonds of the AS500 500/400 brand, less strong — of the AS32 500/400 brand, as well as on the concentration of ultradispersed diamond powders (UDPA or ASM 1/0) in the filler of the tool bundles was studied. These indicators were compared with the indicators of drills equipped with diamond grains of the AS200 500/400 brand, which were obtained and described earlier when drilling the same non-metallic materials. The performance of diamond drills was evaluated by their wear and drilling speed. The highest quality tools can be obtained if you use high-strength diamond grains of the AS500 500/400 brand. The operational characteristics of such drills differed in high wear resistance (low wear) and drilling speed. The efficiency of drilling with diamond drills that were equipped with lower-quality diamond grains of the AS200 500/400 and AS32 500/400 brands was significantly lower. It was possible to increase the drilling speed and reduce the wear of such tools when the filler was introduced into the connection with ASM 1/0 in the amount of 5—7% (wt.) due to the improvement of its mechanical properties. But all the same, such diamond drills were inferior in efficiency to tools equipped with high-quality diamonds of the AS 500 500/400 brand. Keywords: diamond drills, bond samples, drilling tests, drilling speed, wear.

Water treatment membranes embedded with a stable and bactericidal nanodiamond material.

Filtration has emerged as a critical technology to reduce waterborne diseases caused by poor water quality. Filtration technology presents key challenges, such as membrane selectivity, permeability and biofouling. Nanomaterials can offer solutions to these challenges by varying the membranes' mechanical and bactericidal properties. This research uses nanodiamond particles with facile surface functionality and biocompatibility properties that are added to membranes used for filtration treatments. Scanning and transmission electron microscopy (SEM and TEM) and Fourier transform infrared spectroscopy (FTIR) were performed to study the membrane surface. FTIR spectra confirms an increase in oxygen functional groups onto the ultradispersed diamond's (UDD) surface following acid treatment. SEM images show particle deagglomeration of functionalized UDD at the membrane surface. Tensile strength tests were done to measure the UDD mechanical properties and Coliscan membrane filtration characterization was performed to determine the filter effectiveness. Polyether sulfone (PES) and polyvinylidene (PVDF) membranes expressed a change in their yield point when UDD was incorporated into the porous matrix. A significant microorganism reduction was obtained and confirmed using t-test analysis at a 95% level of confidence. UDD-embedded membranes exhibit a significant bactericidal reduction compared to commercial membranes suggesting these membranes have the potential to enhance current membrane filtration systems.

Space Experiment "Obstanovka (1-Step)", Block DP - PM on the Russian Segment of the International Space Station

In the presented work is described the methodology for conducting the technological experiment DP-PM, which is part of the space experiment "Obstanovka 1-step". The DP-PM block was installed on the Russian Segment of the International Space Station in the period from 04/19/2013 to 08/10/2015. The purpose of the experiment is to study the effect of outer space on the properties of graphite samples with a glassy carbon coating and samples of B95 (7075) aluminium alloy with a quantitative addition of ultradisperse diamond powder and tungsten after a long stay in near Earth orbit.

Quantum mechanical modeling of the interaction of ultradispersed diamond particles with nickel ions

Quantum mechanical modeling of the interaction of ultradispersed diamond particles with nickel ions

Modification of a metal surface with detonation diamond nanoparticles

Friction between metal surfaces in various mechanisms is an actual problem in modern engineering. Friction causes wearing of the rubbing parts. For reducing the coefficient of friction, it is proposed to treat the surfaces of rubbing parts with a suspension having a high (more than 20%) content of ultradispersed detonation diamond (UDD). In the course of treatment, nanodiamond particles penetrate into the substance being treated and create a thin surface layer (up to 1000 nm, depending on the degree of part processing), which leads to smoothing the effect of microsliding, due to which the reduction of the friction coefficient. The resulting surface layer consists of a metal matrix with diamond nanoparticles embedded in it. The paper shows the study of the steel part surface with the use of the optical and X-ray methods, and provides information on the change in the coefficient of friction of steel parts.

Effect of Modifying Carbon Materials with Metal Phthalocynines and Palladium on Their Catalytic Activity in ORR

Bimetallic catalysts based on multi-walled carbon nanotubes (MWCNT), graphene oxide (GO) and ultradispersed diamonds (UDD) supports for the process of electroreduction of oxygen from alkaline electrolyte were obtained using high-temperature synthesis. The materials were characterized by low-temperature nitrogen adsorption, Raman spectroscopy, scanning electron microscopy and X-ray structure analysis. The synthesized bimetallic catalysts contain meso- and micropores. Based on the study by Raman spectroscopy, it is shown that high-temperature synthesis of MWCNT with metal phthalocyanines leads to doping of this material with nitrogen and the appearance of significant defects in the structure. Carbon nanotube-based catalysts showed enhanced activity compared to other carbon materials. Moreover, bimetallic catalysts based on cobalt phthalocyanine and palladium (MWCNT_CoPc_Pd) are characterized by higher activity on all carbon supports compared to materials contain on copper and palladium. The specific current density in the diffusion region of the MWCNT_CoPc_Pd catalyst is comparable to a commercial platinum electrode (Pt(20%)/C) and equals to 2.65 mA/cm2. The area of the electrochemically active surface of all the obtained catalysts was calculated from the CV data in a nitrogen atmosphere. The MWCNT_CoPc_Pd catalyst is characterized by high corrosivity: after 2500 revolutions, the current density in the diffusion region decreases by 7%, and, also, an increase in the values of E1/2 and Eonset is observed.

Kinetic regularities of the formation of composite electrolytic coatings containing ultradispersed diamond particles

The paper formulates the problem of joint electrolytic co-deposition of metal ions and ultradispersed diamond particles into a metal matrix. It presents the developed mathematical model that describes the mechanism and kinetics of the cathode process, mass transfer of metal ions and ultradispersed diamond particles. A satisfactory correlation with experimental data was obtained. The contribution of the thermal action of laser radiation to the intensification of the process of co-deposition of dispersed particles and metal ions was determined. It was found that the more intense penetration of dispersed phase particles into the forming coating during the laser stimulation of the electrodeposition process is due to the presence of a temperature gradient, which provides an additional supply of metal ions in the irradiation region. Based on the theoretical and experimental studies, we established the regularities of the influence of the number and size of nanoparticles on the strengthening properties of composite metal coatings. It was found that an increase in the temperature of an aqueous electrolyte solution in the cathode region during a laser-stimulated deposition process leads to an increase in the flux density of ultradispersed diamond particles, and, as a result, to an increase in the concentration of the dispersed phase in nickel composite coatings, which contributes to the formation of a finer crystalline structure of coatings, an improvement in adhesion, strength properties and increased wear resistance of coatings.

Influence of citrate copper-plating electrolyte, its components and ultra-dispersed diamonds additives on surface properties of steel

The state of the steel substrate (steel 3) was studied before the application of composite copper coatings from citrate copper-plating electrolyte. The properties of steel base in the investigated copper-plating electrolyte with the addition of ultradispersed diamonds (UDD) have been studied. A component-by-component analysis of the citrate copper-plating electrolyte was carried out, and the effect of each component on the properties of the steel electrode was evaluated. The possibility of using the considered electrolyte for coating directly on steel is shown, which significantly distinguishes it from currently used ethylenediamine, pyrophosphate, acid and other electrolytes. Electrochemical impedance spectroscopy and cathodic polarization were used as research methods. It was found that the lowest resistance of the steel surface (about 15 Ω) corresponded to the sample immersed in citrate copper-plating electrolyte with the addition of 1.0 g/l of UDD. Diffusion current density for suspensions with 1.0 g/l UDD in citrate copper-plating electrolyte was 2.6 A/dm 2 . Ultradispersed diamonds in citrate copper-plating electrolyte shielded the surface of the steel sample, while reducing the total resistance of the passive layer of steel 3. Equivalent electrical circuits of the surface of steel samples immersed in citrate copper-plating electrolyte and its components are also presented.

Mathematical modeling of the sedimentation process for determining the fractional composition of suspensions

Exceptional prospects for use in science, technology and industry are opened by highly dispersed powders (ultradispersed diamonds, nanoceramics, medicinal powders) and materials based on them. The properties of such materials depend on the particle size determined by sedimentation analysis. An equation is proposed for processing sedimentation analysis data, which does not depend on the size distribution law of polydisperse system particles, and is used to describe the distribution functions of particles with radii for clay suspensions. A program in the Microsoft Visual Basic for Applications (VBA) language has been created for calculating the fractional composition of suspensions according to the proposed equation; the correctness of its operation on a model system has been checked and confirmed. Experimental research has confirmed that the use of the developed program and the "Search for a solution" add-on for the MS Excel environment makes it possible to determine the fractional composition of suspensions. It has been proven that the proposed method can be used to analyze polydisperse systems. It has been found that for the suspensions under consideration, as containing 25 fractions, it is possible to determine the integral curve of the distribution of the masses of the particles of the dispersed phase along the radii. This allows to assert the possibility of using the proposed equation for processing sedimentation analysis data, which does not depend on the law of mass distribution of polydisperse system particles by size. Thus, there is reason to assert about the possibility of a reasonable determination of the fractional composition of any polydisperse systems. It is possible to obtain certain effects from the introduction of sedimentation analysis data processing according to the proposed equation in production, where the fractional composition of dispersed phases is regulated.

Impregnation of Micro- and Ultradispersed Diamond Powders with Copper-Based Alloys for Grinding Tool Manufacture

Impregnation of Micro- and Ultradispersed Diamond Powders with Copper-Based Alloys for Grinding Tool Manufacture

Effect of Reinforcement with Micro- and Ultradispersed Diamond Powders on the Properties of Diamond Tubular Drills During the Processing of Some Non-Metallic Materials

The study presents the results of comparative laboratory tests of diamond tubular drills when drilling window glass, granite, and abrasive stones based on silicon carbide SiC. The tests were carried out in cold running water. Tin bronze containing micro- and ultradispersed diamond powders of ASM 40/28, ASM 10/7 (MDP), ASM 1/0 (UDDP) grades, and molybdenum powder were used as a matrix of the tool. Furthermore, the dependence of the hardness of specially prepared matrix samples on their composition was examined. With an increase in the ASM 1/0 concentration up to 5 wt.% in the reinforcement, the hardness of the matrix samples increased by one-third and reached a maximum of ~96.5 HRB. A further increase in the ASM 1/0 concentration led to a slight decrease in the hardness of the samples. The use of larger diamond powders required a higher concentration, providing high values of hardness. By adding ASM 10/7 in an amount of 10 wt.% and ASM 40/28 in the amount of 40–60 wt.% we managed to increase the hardness of the matrix to the same maximum. The introduction of a reinforcement in a bonding matrix of diamond tubular drills in amount ensuring its maximum hardness has significantly increased the efficiency of their operation. Thus, the wear of drills after glass processing decreased by 2–6 times, and the drilling speed increased by 3–4 times. Drill wear after granite processing has decreased by 50–84 times, and the drilling speed has increased 2.7–6 times, correspondingly. Finally, after processing of an abrasive stone based on silicon carbide SiC, the wear of diamond tubular drills decreased by 1.4– 2.9 times, and the drilling speed increased by 1.5–2.5 times. The effect of additives in the reinforcement of the tool depended on the choice of the diamond powder grade and their concentration. The best option was the introduction of ASM 1/0 (UDDP) powder in an amount of 5– 9 wt.%. The introduction of ASM 10/7, and especially ASM 40/28 (MDP), into the reinforcement required, firstly, their higher concentration (10–40 wt.%), and secondly, was not effective enough since the wear indicators of diamond tools were higher, and the drilling speed was lower.

Modified ultradispersed diamonds based catalytic systems in cross-coupling reactions

Methods for preparation of nanocomposites of modified detonation nanodiamonds (DND) with metallic palladium have been developed and their catalytic activity in the Suzuki-Miyaura cross-coupling reaction in various reaction media has been studied. Methods for the regeneration of palladium-containing nanocomposites from the reaction mixture have been developed. The high catalytic activity of nanocomposites is confirmed by kinetic analysis based on the results of chromatographic analysis of the reaction mixture and is comparable to the literature data about similar catalytic systems. Regenerated nanocomposites showed the retention of catalytic activity for 3 consecutive cross-coupling cycles on model systems.

Electrodeposition kinetics and surface morphology of Ni-B-UDD composite coating

The article presents the results of kinetic investigates of electrodeposition of a composite electrochemical coating based on a nickel-boron alloy. Current efficiency, polarization potentiodynamic researches had shown the joint participation in the electrodeposition process of finely dispersed compounds of nickel hydroxides, poorly soluble nickel and boron compounds present in the electrolyte or formed during electrolysis, and ultradispersed diamond introduced into the electrolyte. Comparison of 2D and 3D scans of the surfaces of the formed coatings confirmed the leveling effect of additives, as well as sparingly soluble nickel and boron compounds on the structure of coatings. The proposed composite electrochemical coatings can be used instead of chrome coatings when restoring parts and units of agricultural machinery.

Experimental Study of Transport Coefficients of Aqueous Suspensions of Nanodiamonds

This article presents experimental data on the coefficients of viscosity and thermal and electrical conductivities, as well as the absorption spectra, of suspensions of ultradispersed diamonds. Suspensions of UDA-S and UDP-A detonation nanodiamond particles, as well as UDP-AG diamond–graphite powder, are used in the experiments. The concentration of nanodiamonds in distilled water is varied within a range of 0.5–5 wt %. It is shown that the technology of purification diamond powders from side products of their synthesis substantially affects the physicochemical properties of aqueous suspensions of these powders.

Enhancing metal processing efficiency based on using a lubricating-cooling agent with ultradispersed diamond powder

The present study describes a new technological environment based on ultradispersed diamond graphite powder. The task is to further study effects of lubricating and cooling agent containing diamond nanopowder. The agent is fed into the zone of refinement or polishing of the part while affecting wear and durability of carbide tooling. The impact of the agent on the quality of the surface layer in the processing of heat-resistant steels and alloys is investigated. It also identifies the optimal agent composition when polishing a particular material. Experimental studies established a positive effect of the agent on the treated surface quality and other parameters of clean finishing and polishing of various metals.