The process of anodic oxidation of aluminum and its alloys in the presence of a diamond blend (DB) obtained by detonation of tetryl ( N -methyl-2,4,6-trinitrophenylnitramine) is studied. It is shown that the use of a DB is highly promising for the preparation of a corrosion-resistant wearproof high-hardness anodic oxidation coating, the parameters of which are 1.6 times higher than those of the coatings obtained by the standard process in a standard electrolyte. The concentration of the DB in the sulfuric acid electrolyte is 2–3 g/L.

In this study, an attempt is made to predict the yield of detonation nanodiamonds (DND) from explosives with still underestimated capabilities, such as trinitrobenzene, hexanitroazobenzene, tetranitrobenzotriazolobenzotriazole, trinitrotriaminobenzene, trinitrophenol, and benzotrifuroxan. Knowing the detonation velocity of explosives, one can determine the power density of explosives and then the yield of DNDs on the basis of previously determined dependences or directly determine the yield of DND in a narrow range for each explosive and subsequently verify the obtained values experimentally.

The possibility of formation of detonation nanodiamond (DND) protostructures in the plasma of a chemical reaction zone in the form of a fractal carbon network with spatially ordered carbon nuclei in its nodes is shown; the density of the nodes should be in the range of 2.5–3.2 g/cm3. Upon passing through the Chapman–Jouguet plane, the plasma carbon formations crystallize into DND or amorphize. Detonation nanodiamond is formed at a distance of one third to three quarters of the charge diameter from the detonation wave front. Under optimal conditions, around 20 wt % of total explosive carbon is utilized for the formation of DND.

The paper presents the results of studying the nickel electroplating process in the presence of nanodiamond additives. It shows that the use of detonation nanodiamonds (DND) and diamond explosive charge (DC) obtained by explosion of tetryl (N-methyl-2,4,6-trinitrophenylnitramine) can significantly improve the physicochemical properties of nickel platings: increase the microhardness up to 60 % (up to 448 kgf/mm2 – 4393 MPa), obtain a non-porous nickel plaiting and reduce wear up to 28 times. The most effective was the use of non-expensive nanodiamonds, but cheap diamond charge obtained by the explosion of tetrile.

A technology is developed for producing detonation nanodiamonds (DNDs) from individual compounds (tetryl and picric acid) and binary compositions with a tetryl content of ≥50 wt %. A DND yield of up to 7.5 wt % is achieved. The main trends in the dependence of the DND yield on the content of tetryl mixed with TNT, RDX, and picric acid are established. The dependences of the DND content in the diamond batch on the composition of the explosive and the pressure in the Chapman–Jouguet plane are determined.

To determine the dependence of the yield of detonation nanodiamonds (DNDs) on the power of explosives used, a new concept is introduced—the specific power of explosives (to which the detonation velocity of explosives and the pressure of gases in the Chapman-Jouguet plane are related), which is given by the ratio of the heat of explosion to the unit mass and time. The DNDs yield has been found to depend on the detonation velocity and pressure in the Chapman-Jouguet plane. The optimum yield of DNDs (> 5 wt %) is achieved when the specific power of explosives is 30000 to 60000 kJ/(kg·µs), the detonation velocity is 7250 to 8000 m/s, and the pressure in the Chapman-Jouguet plane is 21 to 28 GPa.

The use of modified detonation nanodiamonds in the most common gold-plating electrolytes—citrate and phosphate—makes it possible to increase microhardness by a factor of about 1.2 and wear resistance from 3.6 times up to that of a practically non-abradable coating, while keeping unchanged the electrolyte formulations, temperature, and current density which are typically used in the conventional technological process. The coating thickness is recommended to be reduced 2- to 3-fold.

Efficiency of using detonation nanodiamonds is strongly affected by the amount and elemental composition of impurities. The study considers the possibility of affecting the yield of detonation nanodiamonds and diamond-containing stock and the content and composition of incombustible impurities in the stock and diamonds by varying the composition of the water armor (shell) of the classical TNT–hexogen (50/50) charge. As compounds affecting the above parameters were used hydrazine, urotropin, ammonia, urea, Trilon B (disodium salt of ethylene diamine tetraacetic acid), aminotetrazole, and boric acid. It was found that using urotropin was the optimal as regards a whole set of parameters. In this case, the maximum yield of detonation nanodiamonds (6.9%) and diamond-containing stock (13.4%) was obtained. A close yield of the diamond-containing stock and detonation nanodiamonds was provided by using hydrazine and urea in the armor. Use of boric acid in the armor can substantially diminish the variety of impurity elements in the diamond-containing stock and detonation nanodiamonds at an acceptable yield of the diamond-containing stock (11.1%) and detonation nanodiamonds (6.13%). Use of pure water as the armor is inefficient.

The paper addresses the detonation synthesis factors that govern the yield of nanodiamonds and diamond-containing soot, and their quality. The effect of such an important factor as the composition of armor (shell) of the explosive charge is described. The authors discuss three different methods of initiating an explosive charge, which involve the use of gas, water, or ice, respectively, and their advantages and disadvantages. The influence of the composition of mixtures of aqueous solutions of various substances (organic and inorganic) on the outcome of the detonation synthesis is shown in detail.

The study of the kinetics of aluminum oxidation process in the presence of modified nanodiamonds and diamond-containing soot (DND-TAN and DCS-boron, respectively) shows their impact on the growth and quality of anodic films: the film thickness and the current efficiency have increased by 13 % at 2 A/dm2 and using DCS-boron; the number of pores has been reduced two-fold using nanodiamond additives; no pinholing has been detected; micro-hardness of the oxide coating has increased 1.5 to 1.6 times (up to 1020 kg/mm2).

The influence of detonation of nanodiamonds doped with boron during the detonation synthesis (DND-boron) on the process of electrochemical deposition of zinc from a zincate electrolytic solution is investigated. It is shown that the throwing power (the coating uniformity) increases 2to 4-fold depending on the DND–boron concentration, the electrolytic conductivity remains unchanged, the corrosion resistance (as measured by the corrosion currents) of the Zn–DND-boron coating grows 2.6 times when tested in the 3% NaCl solution and 3 times in the climatic chamber.

The effect of detonation nanodiamonds, doped with boron (boron-DND) in detonation synthesis on the process of zinc electrochemical deposition from zincate electrolyte is investigated. It is shown that the scattering power (coating uniformity) increases 2-4 times (depending on the concentration of DND-boron electrolyte conductivity does not change, the corrosion resistance of Zn- DND -boron coating increases 2.6 times in 3% NaCl solution (corrosion currents) and 3 times in the climatic chamber.

Samples of detonation nanodiamonds modified during the synthesis by adding doping elements in various ways have been studied by spectroscopic methods (electron paramagnetic resonance, Raman scattering, and X-ray diffraction). For the first time, the presence of P1 centers in detonation nanodiamond crystals has been indirectly demonstrated. The authors discuss the nature and distribution of spins as observed by the electron paramagnetic resonance, the composition of phases and size of the coherent scattering region, and crystal density (calculated by the X-ray method) of the detonation nanodiamond samples at hand.

The authors compare IR spectra of diamonds of different origins, both natural and synthetic ones—produced by detonation, dynamic, and static syntheses, and subjected to purifying treatment under various conditions. It is shown that in the IR-spectral range there are absorption bands at 421, 945, 1022, 2854, 2920, and 3368 cm–1, which are typical of the majority of the samples studied. Whatever the origin of diamonds, their IR spectra have been found to contain absorption bands of S–S, C–S bonds (upon treatment with sulfuric acid), and C–N bonds (after treatment with nitric acid). The presence of functional C–H and–OH groups has been confirmed.

The paper addresses the basic mechanism of deposition of electrochemical chromium-diamond coatings and shows the results of producing such coatings with detonation nanodiamonds of various types and static-synthesis nanodiamonds. The process kinetics and the state of nanodiamonds in a universal chromium plating solution are studied; the paper shows the influence of nanodiamonds on micro- and macrostructure, physical-mechanical properties of the chromium-diamond coatings and surface morphology of the coatings; usability of modified diamond-containing soot is demonstrated. Chromium plating processes involving detonation nanodiamonds from various manufacturers are compared; microhardness is shown to reach 1400 kgf/mm2, wear resistance to increase six-fold, corrosion resistance to increase by a factor of more than 8.

IR-spectra of a great number of samples of detonation nanodiamonds (DND) obtained under different conditions (with dopants added or with the use of reducing agents) have been analyzed for the first time. The quantity and type of incombustible impurities have been found to have no effect on the pattern of IR spectra. It is shown that in the IR-spectral range there exist some narrow frequency ranges where the majority of DND exhibit absorption regardless of the synthesis conditions (829, 1365, 1558, 1628, 1732, 2341, 2858, 2928 cm −1 ). IR-spectra confirm the presence of nitrogen impurity centers in new DNDs and of the functional groups NO 2 , CH, NO 3 , CH 2 , OH, C=O on the DND surface.

The paper presents new alternative procedures of chemical purification of detonation nanodiamonds and diamond-bearing detonation soot to remove water-insoluble metal-containing impurities through a high-temperature treatment using solutions of complexons of concentration 0.5 to 20 wt %, where the ratio between the detonation nanodiamond material and the complexon is above 0.2. The following substances can be used as complexons: sodium 2,3-dimercaptopropanesulfonate, disodium dihydrogen ethylenediaminetetraacetate (Trilon), thiocarbamide, potassium rhodanate, dicyandiamide, hexamethylenetetramine. Purification of detonation nanodiamonds can be also performed by exposing them to an ultrasonic action. A combination of the ultrasonic treatment and treatment with complexon solutions has proved most efficient, significantly reducing the amount of metal-containing impurities.

New procedures were developed for chemical treatment of detonation nanodiamonds and diamond- containing detonation blend to remove water-insoluble metal-containing impurities. The detonation nanodiamond material is treated with complexing agent solutions under cavitation conditions and at high temperature and pressure. Sodium 2,3-dimercaptopropanesulfonate (Unithiol), disodium dihydrogen ethylenediaminetetraacetate, thiourea, potassium thiocyanate, dicyandiamide, and hexamethylenetetramine are used as complexing agents. The com- plexing agent concentration in solution is 0.5-20 wt % at the nanodiamond material to complexing agent weight ratio higher than 0.2. The use of aqueous solutions of the complexing agents at high temperatures and pressures appeared to be the most effi cient.

New procedures were developed for chemical treatment of detonation nanodiamonds and diamond-containing detonation blend to remove water-insoluble metal-containing impurities. The detonation nanodiamond material is treated with complexing agent solutions under cavitation conditions and at high temperature and pressure. Sodium 2,3-dimercaptopropanesulfonate (Unithiol), disodium dihydrogen ethylenediaminetetraacetate, thiourea, potassium thiocyanate, dicyandiamide, and hexamethylenetetramine are used as complexing agents. The complexing agent concentration in solution is 0.5–20 wt % at the nanodiamond material to complexing agent weight ratio higher than 0.2. The use of aqueous solutions of the complexing agents at high temperatures and pressures appeared to be the most efficient.

A new mechanism of formation of nanodiamond particles during detonation synthesis has been put forward. It includes the following steps: (a) decomposition of trinitrotoluene (TNT) molecules into basic radicals-a radical-like dimer C2 and CO3, decomposition of hexogen molecules into C2 and of benzotrifuroxane molecules into C2; (b) formation of cyclohexane from C2 or immediately of radical adamantane molecules; (c) interaction of diamond-like core (adamantane radical) with methyl and other monocarbon radicals; and (d) growth of detonation nanodiamond particles like in a CVD process. It is shown that the nucleation of a radical-like adamantine molecule occurs within a range between the center of the chemical peak zone and the Chapman-Jouguet plane, the growth of diamond particles takes place at the same time and comes to an end at an early stage of isoentropic (Taylor) expansion of detonation gases entrapping solid carbon particles.