Detonation Synthesis Nanodiamonds Research Articles

Detonation Synthesis Nanodiamond Soot as a Promising Filler for Polymer Composites

In this work, the results of a complex investigation of structure and properties of nanodiamond soot (NDS) of detonation synthesis are presented. Size distribution of NDS particles, dispersed in different liquid media, was investigated using dynamic light scattering and laser diffraction analysis methods. The results of the investigation, as well as the results of zeta-potential measurements, allowed us to characterize the agglomeration process of the NDS particles as independent of the medium, making NDS a good model filler for research of composite-modified nanosized particles. Additional data obtained using scanning electron microscopy, scanning tunneling microscopy, atomic force microscopy, X-ray diffraction, and Raman spectroscopy, demonstrated that in NDS the spherical nanodiamond (ND) particles with diameter ~5 nm are densely packed into strong-coupled aggregates with diameter ~300 nm, surrounded by graphite nanoribbons. X-ray diffraction analysis estimated the volume fraction of NDs in NDS as ~45 vol.%, simultaneously showing that the graphite is not defective, which was confirmed with the electron diffraction method. It was demonstrated that this structure of NDS allows to efficiently use NDS as a filler for polymer composites to increase polymer characteristics such as electrical conductivity or tribological characteristics, similarly to conventionally applied fillers such as carbon black.

Biodistribution of Detonation Synthesis Nanodiamonds in Mice after Intravenous Administration and Some Biochemical Changes in Blood Plasma.

Biodistribution of nanodiamonds in mice after intravenous administration, activities of AST and ALT, and the level of bilirubin in the blood plasma were studied in 2.5 h and 10, 35, and 97 days after injection of nanodiamonds. In 2.5 h after intravenous injection, nanodiamonds mainly accumulate in the lungs and liver. Then, redistribution of nanodiamonds from all organs to the liver was observed. Activities of AST and ALT and the level of bilirubin in the blood increased after 2.5 h and then decreased to the initial values.

Investigation of the Morphology and Atomic Structure of Nanopowder Particles Obtained by Grinding Natural Diamond and by the Method of Detonation Synthesis

By a complex of high-resolution methods, it has been shown that the nanopowder particles obtained by grinding natural diamonds have a wide range of sizes and are predominantly lamellar in contrast to the detonation synthesis nanopowder, which consists mainly of similar in size and isometric particles. The primary particles of the nanopowder obtained by grinding, as well as detonation synthesis nanodiamonds, consist of diamond cores with cubic crystal lattices surrounded by shells with complex structures formed from carbon atoms in the sp2 state and impurities. A noticeable increase in the interatomic distances in nanodispersed diamond crystals is observed compared to those for bulk diamond crystals.

Рентгеновская фотоэлектронная спектроскопия наноалмазов, полученных измельчением и детонационным синтезом

The chemical composition and surface state of nanopowder particles prepared by milling natural diamond and detonation synthesis were studied by the method of X-ray photoelectron spectroscopy. It has been shown that the primary particles of both nanopowders contain mainly carbon and oxygen atoms. The signals in the photoelectronic spectrum from atoms of nitrogen, sulfur, chlorine and metals do not exceed the noise level. It was found that in primary particles of detonation synthesis nanodiamond and nanopowder obtained by grinding natural diamond, the proportions of carbon atoms in the sp3 hybridization state are ~ 46.5 and ~ 67.8%, sp2 hybridization is ~ 26.8 and ~ 17.4% and in the composition of oxygen-containing functional groups ~ 26.7 and ~ 14.7%, respectively.

Core–Shell Composites Based on Partially Oxidized Blend of Detonation Synthesis Nanodiamonds

The results of a study on the production of graphite–diamond nanocompositions by partial oxidation of a detonation synthesis blend in aqueous solutions of nitric acid under pressure in the temperature range 120–230°C are presented. A part of the graphite shell was subjected to selective oxidation. According to the results of kinetic studies in a 400 mL autoclave, an oxidation process scheme is proposed, which is based on a radical chain reaction involving nitrogen dioxide and carbon of graphite/graphene shell on the surface of the particles. The synthesis conditions for the main types of graphite–diamond nanocomposites of various oxidation states are determined. On a pilot installation in a swinging titanium autoclave of a 12 L capacity, experimental batches of the product were accumulated, which made it possible to assess the possibility of scaling the developed laboratory process.

Inorganic Pyrophosphatase-Nanodiamond Conjugates Hydrolyze Pyrophosphate in Human Synovial Fluid.

The present work is focused on testing enzyme-based agents for the partial dissolution of calcium pyrophosphate (CaPPi) deposits in the cartilages and synovial fluid of patients with pyrophosphate arthropathy (CPPD disease). Previously, we suggested that inorganic pyrophosphatases (PPases) immobilized on nanodiamonds of detonation synthesis (NDs) could be appropriate for this purpose. We synthesized and characterized conjugates of NDs and PPases from Escherichia coli and Mycobacterium tuberculosis. The conjugates showed high enzymatic activity and resistance to inhibition by calcium and fluoride. Here, we tested the effectiveness of pyrophosphate (PPi) hydrolysis by the conjugates in an in vitro model system simulating the ionic composition of the synovial fluid and in the samples of synovial fluid of patients with CPPD via NMR spectroscopy. The conjugates of both PPases efficiently hydrolyzed triclinic crystalline calcium pyrophosphate (t-CPPD) in the model system. We evaluated the number of phosphorus-containing compounds in the synovial fluid, showed the possibility of PPi detection in it, and estimated the hydrolytic activity of the PPase conjugates. The soluble and immobilized PPases were able to hydrolyze a significant amount of PPi (1 mM) in the synovial fluid in short periods of time (24 h). The maximum activity was demonstrated for Mt-PPase immobilized on ND–NH–(CH2)6–NH2 (2.24 U mg–1).

Synthesis of Inorganic Pyrophosphatase-Nanodiamond Conjugates Resistant to Calcium and Fluoride.

Pyrophosphate arthropathy is the mineralization defect in humans caused by the deposition of microcrystals of calcium pyrophosphate dihydrate in joint tissues. As a potential therapeutic strategy for the treatment of pyrophosphate arthropathy, delivery of exogenous pyrophosphate-hydrolyzing enzymes, inorganic pyrophosphatases (PPases), to the synovial fluid has been suggested. Previously, we synthesized the conjugates of Escherichia coli PPase (Ec-PPase) with detonation synthesis nanodiamonds (NDs) as a delivery platform, obtaining the hybrid biomaterial retaining high pyrophosphate-hydrolyzing activity in vitro. However, most known PPases including Ec-PPase in the soluble form are strongly inhibited by Ca2+ ions. Because synovial fluid contains up to millimolar concentrations of soluble calcium, this inhibition might limit the in vivo application of Ec-PPase-based material in joint tissues. In this work, we proposed other bacterial PPases from Mycobacterium tuberculosis (Mt-PPase), which are resistant to the inhibition by Ca2+ ions, as an active PPi-hydrolyzing agent. We synthesized conjugates of Mt-PPase with NDs and tested their activity under various conditions. Unexpectedly, conjugates of both Ec-PPase and Mt-PPase with aminated NDs retained significant hydrolytic activity in the presence of well-known mechanism-based PPase inhibitors, fluoride or calcium. The incomplete inhibition of PPases by fluoride or calcium was found for the first time.

Морфология и структурное состояние частиц нанопорошков, полученных измельчением природного алмаза и методом детонационного синтеза

A complex of high-resolution methods has revealed that the nanopowder particles obtained by milling natural diamonds have a wider variety of sizes and predominantly of lamellar shape in contrast to detonation synthesis nanopowder, which consists mainly of similar-sized and isometric particles. The primary particles of the nanopowder obtained by milling, as well as detonation synthesis nanodiamonds, consist of diamond nuclei with cubic crystal lattices surrounded by shells with complex structures, which are formed from carbon atoms in the sp2-state and impurities. A noticeable increase in interatomic distances in nanodispersed diamond crystals has been established compared with those for large diamond crystals.

Comparison of morphological and structural characteristics of nanopowder particles obtained by natural diamond grinding and detonation synthesis

The study covers specific features of morphological and structural characteristics exhibited by nanopowder particles obtained by grinding a massive natural diamond and the method of detonation synthesis. High-resolution transmission and scanning electron microscopy, small-angle X-ray scattering demonstrated that natural diamond nanopowder particles obtained by grinding have a wider range of sizes and a plated appearance, unlike detonation synthesis nanopowders consisting of similar in size and isometric particles. X-ray diffraction analysis and Raman spectroscopy used in addition to the methods mentioned above showed that the structure of nanodiamond particles obtained from natural diamond is similar to the structure of a detonation synthesis nanodiamond. Each particle of natural nanopowder, as well as detonation synthesis nanodiamond, consists of a diamond core with a crystal lattice related to the cubic system and a shell containing mainly non-diamond carbon forms with sp 2 hybridization having a complex structure. The average particle size of nanopowders obtained from natural diamond and using detonation synthesis studied by three methods including BET showed results that are in satisfactory agreement with each other. The average nanoparticle size is about 24 nm for natural diamond powder and close to 5.6 nm for UDA-S-GO detonation synthesis nanodiamonds produced by the Federal Research and Production Center «Altai». An insignificant increase in the interatomic distances in diamond nanocrystals compared with a massive diamond crystal was shown experimentally. The study and analysis of a numerous images of natural and detonation synthesis diamond nanocrystals obtained by high-resolution transmission electron microscopy made it possible to establish that the most frequent defects in nanodiamonds are dislocations and point defects.

Caries preventive effect of toothpastes with detonation nanodiamonds on the dental enamel of rats

The aim of the study was to evaluate the abrasive effect of toothpaste with nanodiamonds of detonation synthesis of different concentrations on tooth enamel of experimental animals (rats). The analysis of microphotographs obtained by scanning electron microscopy from all studied groups showed different abrasive and polishing effects of nanodiamonds in all observed anatomical zones on the vestibular surface of rat tooth enamel. At all concentrations of pastes containing nanodiamonds, tightly attached nanodiamonds were observed on the vestibular surface of the enamel of the teeth under study, there was a tendency to the formation of depots. It is interesting to note that on the enamel of the teeth of rats, even after treatment with a paste with the lowest concentration of nanodiamonds 0.5%, except for single deposits of nanodiamonds, in some places there were clusters that combine into a layer in the form of a protective film.The study showed that toothpaste with nanolaser capable of reducing the porosity of the enamel on its surface to form a protective film, thereby increasing its microhardness, and resistance.

Bacteria Rhodococcus sp. as Potential Destructors of Detonation Nanodiamonds

The effect of detonation-synthesis nanodiamonds (NDs) on the viability of bacterium Rhodococcus sp. 2012B and its capability for ND biodegradation was determined. It was shown that NDs did not decrease the viability of bacterium Rhodococcus sp. 2012B. The bacterium remained resistant to all tested ND concentrations (0.25, 0.5, 5, and 10 mg/mL). It is found that Rhodococcus sp. 2012B is able to maintain its population size during the absence of alternative carbon sources in the presence of even small ND concentrations in the medium. It was determined that the number of viable cells of Rhodococcus sp. 2012B increased almost two times in the presence of high ND concentrations in the presence of an other available carbon source. Thus, bacterium Rhodococcus sp. 2012B can be considered a potential biodestructor of detonation nanodiamonds.

Effect of physicochemical action on the aggregative properties of detonation-synthesized nanodiamonds

The results of researches of physicochemical action on aggregate properties of nanodiamond are presented. The kinetics of aggregation of nanodiamond powder was studied as a function of time, temperature, and pH of the solution. The effect of the sp2–sp3 hybridization ratio of carbon in nanodiamond powders on their aggregation was studied. It is shown that the presence of non-diamond carbon in detonation synthesis nanodiamond powders leads to the increase of the mean diameters of particles, i.e., their agglomeration. The theoretical justification of the aggregation mechanism is proposed. It is shown that it is possible to control aggregative properties of nanodiamond powders by physicochemical influences, e.g., gas-phase thermal treatment to reduce the size of agglomerates and to create a well-developed reconstructed surface of diamond particles with a low content of functional groups on their surface.

The Structure and Main Characteristics of Diamond-Bearing Ni–P Coatings

The effect of detonation-synthesis nanodiamonds (extracted from detonation products by thermal treatment in air in the presence of boric anhydride) on the characteristics of chemical composite nickel–phosphorous coatings has been investigated. It has been established that the introduction of nanodiamonds results in formation of a finer structure of the obtained coatings, reduction in the size of the coherent-scattering region, and an increase in the size of the crystal-lattice parameter. The coatings’ microhardness increased by 30% on average. Application of nanodiamonds with a surface modified with nickel compounds has yielded an additional increment of the microhardness of composite coatings by 33%.

On the lubrication mechanism of detonation-synthesis nanodiamond additives in lubricant composites

The lubrication of detonation-synthesis diamond additives in lubricant composites has been discussed. The mechanism of interaction between nanodiamonds and friction surface has been shown to depend on the applied load. Two models of the lubrication of nanodiamonds and the conditions for their validity have also been proposed.

Spectroscopic properties of polycrystals of supramolecular europium complexes with bathophenanthroline

Nanostructured supramolecular complex of europium(III) with bathophenanthroline (bphen), with detonation synthesis nanodiamonds (NDs) used as a structure-forming element, has been synthesized for the first time. The characteristics of the Eu(bphen)2(NO3)3 complex and the supramolecular complex with NDs, ND–Eu(bphen)2(NO3)2, are studied and compared using scanning electron microscopy (SEM), luminescence spectroscopy, IR spectroscopy, and electron-spin resonance (ESR) spectroscopy. The luminescence quantum yields of the complexes are estimated by the relative method using a β-diketonate complex of europium (III) with tris(thenoyltrifluoroacetone) and 1,10-phenanthroline (Eu(TTA)3phen) as a reference. It is found that the ND–Eu(bphen)2(NO3)2 supramolecular complex has a higher photoresistance than the complex without NDs and no worse thermal stability (up to a temperature of +150°C).

Humic substances alter the uptake and toxicity of nanodiamonds in wheat seedlings

Detonation synthesis nanodiamonds (ND) are among the most widely applied nanoparticles due to their low cost of production and broad scope of applications. However, the fate and behavior of NDs in the environment are largely unknown. The behavior of NDs is greatly affected by humic substances (HSs), which comprise 50 to 80 % of natural organic matter in water and soil ecosystems. The uptake of detonation NDs by wheat seedlings and its toxicity were evaluated in the presence of seven HSs of different origins, including humic acids (HA, HS fraction soluble in alkali and insoluble in acid) and fulvic acids (FA, soluble in both alkali and acid). To monitor the uptake of NDs by plants, tritium-labeled NDs were produced. Liquid scintillation spectrometry and autoradiography were used to determine the amount of NDs absorbed by plants. The photosynthetic activity of the plants was measured using light response curves. After a 24-h exposure period, the ND content in the plant roots was 1720 μg g−1. The introduction of HSs decreased the ND contents in the plant roots to 680–1570 μg g−1 (except for peat FA, for which the ND content did not differ from the blank value). The observed phenomenon was probably related mainly to the influence of HSs on the zeta potential of the NDs, which shifted from positive to negative. Based on chlorophyll fluorescence evaluation, the toxicity of NDs did not inhibit photosynthesis during illumination in the physiological range. However, NDs were slightly toxic to wheat plants under excessive light, likely due to the inhibition of electron transport between Q A and Q B and the disruption of the formation of a thylakoid transmembrane potential. The introduction of HA in a suspension of NDs obviously reduced the inhibiting effect of the NDs; however, the mitigating activities of FA were not so apparent. Our results demonstrate the urgent need for further studies of the influences of NDs on plant growth and development.

Detonation-Synthesis Nanodiamonds in Compositions of Ultrahigh-Molecular-Weight Polyethylene

A study has been made of the influence of an ultradisperse carbonaceous product, i.e., detonation-synthesis nanodiamonds, on the structure and properties of nanocomposites based on ultrahigh-molecular-weight polyethylene using electron microscopy and acoustic, electrophysical, thermomechanical, and x-ray phase analysis methods It has been shown that a diamond blend is a structurally active filler of ultrahigh-molecular-weight polyethylene, which changes the crystalline and supermolecular structure of the polymer during its melt crystallization under the conditions of uniaxial plastic deformation. The developed polymer nanocomposites based on ultrahigh-molecular-weight polyethylene, which contain 0.5–0.25 wt.% of the diamond blend, possess higher than average indices of hardness, modulus of elasticity, and electrical conductivity manifested to a larger extent in the frequency range 1–10 kHz, a low friction factor (0.15–0.18), and high resistance to wear under dry-friction conditions (the wear rate is 10–4–10–5 mg/m).

Ethanol and methanol steam reforming on transition metal catalysts supported on detonation synthesis nanodiamonds for hydrogen production

In this paper we report the results obtained by the comparative study of catalytic activity of monometallic (Ni, Cu, Ru, Pt) and bimetallic (Pt–Ni, Pt–Cu, Pt–Ru) catalysts synthesized on a surface of detonation nanodiamond (DND) supports in steam reforming of methanol and ethanol for hydrogen production. All obtained catalysts (M/DND) were characterized by TEM, FTIR spectroscopy, X-ray diffraction. The specific surface area of DND-nanocomposites was also evaluated by using BET technique. The obtained M/DND catalysts demonstrated high activity in methanol and ethanol steam reforming reactions. It has been shown that the most active monometallic catalyst is ruthenium one, while Pt–Ru catalyst demonstrates the highest activity in comparison with other bimetallic samples.

Small-angle neutron scattering study of the mesostructure of bioactive coatings for stone materials based on nanodiamond-modified epoxy siloxane sols

The structure formation of sol-gel-derived epoxy siloxane compositions with different ratios of the main precursors (RTEOS/EPONEX 1510 = 16/38, 27/27, 38/16 wt %) and with different concentrations of detonation synthesis nanodiamonds (cDND = 0.05, 0.10, 0.20 wt %) has been investigated using small-angle neutron scattering (SANS). Based on the SANS data, it has been revealed that the synthesized epoxy siloxane xerogels are systems with a two-level fractal structure, in the formation of which the siloxane component plays a dominant role. It has been found that the fractal dimension Dm2 and the radius of gyration Rg2 of clusters in the epoxy siloxane compositions decrease with an increase in the content of the siloxane component. It has been established that the introduction of small additions of detonation synthesis nanodiamonds (less than 1 wt %) into the epoxy siloxane composition with an equal ratio of the main precursors RTEOS/EPONEX 1510 = 27/27 wt % leads to a transition from the two-level to three-level structure organization and affects the fractal dimension Dm and the radius of gyration Rg of the formed clusters.

Effect of the detonation nanodiamond surface on the catalytic activity of deposited nickel catalysts in the hydrogenation of acetylene

A comparative study is performed of the catalytic activity of nanosized nickel deposited on detonation synthesis nanodiamond (DND) and coal (CSUG) produced by burning sugar and crystalline quartz in the hydrogenation of acetylene. Nanosized nickel is obtained through the thermal decomposition of nickel formate under a dynamic vacuum. The catalysts are studied by means of scanning electron and transmission electron microscopy, X-ray fluorescence, IR-spectroscopy, X-ray diffraction, and pulse microcatalytic method. It is shown that Ni/DND is an active catalyst of acetylene hydrogenation, considerably surpassing Ni/quartz and Ni/CSUG. The apparent activation energy of the hydrogenation of acetylene is calculated, and the region of the reaction are determined for all catalysts. It is found that the influence of the structure and nature of a functional coating of nanodiamond on the catalytic activity of Ni/DND deposited catalyst in the hydrogenation of acetylene. The ability of Ni/DND to hold active hydrogen is detected.