共查询到20条相似文献,搜索用时 31 毫秒
1.
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. 相似文献
2.
A. P. Voznyakovskii B. M. Ginzburg D. Rashidov D. G. Tochil’nikov Sh. Tuichiev 《Polymer Science Series A》2010,52(10):1044-1050
The effect of modifying additives based on detonation nanodiamonds on the tribological characteristics of polyurethane rubber
is studied. Introduction of modifying additives based on detonation nanodiamonds (0.5 wt %) leads to a marked improvement
in the antifriction and wear-resistance characteristics under conditions of boundary sliding friction for steel and for lubrication
with water. The attained tribological characteristics (total energy loss for friction, weight loss of polymer during tribological
contact, maximum admissible working pressure) are well (∼300%) above the corresponding characteristics of foreign analogs.
Changes in the tribological characteristics of the formed nanocomposite material are observed, but the elastic and strength
characteristics remain unchanged. 相似文献
3.
The structure and properties of composite materials based on amorphous thermoplastics and detonation nanodiamonds are studied.
The conception of the “rheological method” is advanced for compatibilization of a polymer and a filler under the regime of
elastic turbulence (spurt) for preparation of composites with a high level of dispersion and a homogeneous distribution of
nanodiamond particles. As a rule, the dependences of strength and physicomechanical characteristics of the nanocomposites
on the content of the dispersed phase are described by curves with an extremum or saturation. The concentration of the filler
corresponding to the extremum or the approach to the plateau value for a specific parameter depends on the nature of the polymer
matrix and is attained at filler contents below 2.5 wt %. The elastic modulus monotonically increases as the content of nanodiamonds
is increased to 5 wt %. 相似文献
4.
A. P. Voznyakovskii A. V. Kalinin M. V. Mokeev L. V. Agibalova E. N. Vlasova 《Russian Journal of Applied Chemistry》2012,85(7):1090-1094
The method was developed for surface defunctionalization of detonation nanodiamonds by substitution of a perfluorinated organic radical for hydroxyl and carboxyl groups. Size-mass distributions of modified particles of detonation nanodiamonds in water and toluene were studied 相似文献
5.
V. Yu. Dolmatov A. Vehanen V. Myllymäki K. A. Rudometkin A. N. Panova K. M. Korolev T. A. Shpadkovskaya 《Russian Journal of Applied Chemistry》2013,86(7):1036-1045
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. 相似文献
6.
V. Yu. Dolmatov 《Russian Journal of Applied Chemistry》2006,79(12):1913-1918
Concepts concerning the structure of detonation nanodiamonds were generalized on the basis of data reported in previous publications. The pH value of the nanodiamonds in an aqueous suspension was determined. The mechanism of the longest stage, washing of nanodiamonds with water to remove excess acidity, was considered. A novel method for substantially improving the quality of nanodiamonds and the stability of aqueous suspensions of nanodiamonds was suggested. 相似文献
7.
K. A. Shashkeev O. V. Popkov G. Yu. Yurkov S. V. Kondrashov A. A. Ashmarin M. I. Biryukova 《Russian Journal of Applied Chemistry》2016,89(4):644-649
Tribological materials based on molybdenum disulfide nanoparticles localized on the surface of ultradispersed polytetrafluoroethylene were prepared. The composition and properties of the new composite materials were studied. Introduction of ultradispersed additives based on polytetrafluoroethylene with MoS2 and on polytetrafluoroethylene and nanodiamonds prepared by detonation synthesis (taken as reference samples) decreases the viscosity of MS-20 aviation oil. The dependence of the friction coefficient on the Sommerfeld number for the composites obtained was examined. Introduction of additives leads to a decrease in the friction coefficient with increasing linear sliding velocity, in contrast to the initial oil for which the trend is opposite. The dependence of the friction coefficient on the concentration of additives in the initial oil was demonstrated. Modification of polytetrafluoroethylene microgranules with 3 wt % MoS2 nanoparticles allows the amount of additive to the oil to be considerably reduced. 相似文献
8.
E. Yu. Mironova M. M. Ermilova M. N. Efimov L. M. Zemtsov N. V. Orekhova G. P. Karpacheva G. N. Bondarenko N. A. Zhilyaeva D. N. Muraviev A. B. Yaroslavtsev 《Russian Chemical Bulletin》2013,62(11):2317-2321
Physicochemical properties and catalytic performance of detonation nanodiamonds were studied. Original samples of nanodiamonds and nanodiamonds modified by hydrogen, oxygen, and nitric acid with hydrogen peroxide and infrared-treated were investigated. The catalyst structure and morphology were examined by transmission electron microscopy and IR spectroscopy. All the investigated catalysts were active in the steam reforming of ethanol. The correlation of catalytic properties with composition and structure of the described systems is discussed. The specific surface area of nanodiamonds is changed insignificantly upon modification. 相似文献
9.
V. A. Lapina G. S. Akhremkova T. M. Gubarevich Yu. Schreiber 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2010,84(2):267-271
The adsorption of benzene and water vapors on the surface of detonation nanodiamond powders that differed in particle size,
degree of their strong aggregation, and chemical state of their surface was studied. Specific features of the processes of
adsorption of polar and nonpolar molecules on chemically modified surfaces of nanodiamonds are analyzed. 相似文献
10.
G. A. Chiganova D. A. Chul’myakova L. E. Mordvinova T. I. Petrova 《Russian Journal of Applied Chemistry》2012,85(2):177-181
Adsorption of nickel (II) ions with nanodiamonds obtained by the detonation synthesis was studied. A nickel-substituted form
of nanodiamonds was obtained. The catalytic activity exhibited by nickel ions (II) in the form of the surface complexes with
nanodiamond functional groups in decomposition of hydrogen peroxide was determined. 相似文献
11.
Dorokhov A. O. Dolmatov V. Yu. Malygin A. A. Kozlov A. S. Marchukov V. A. 《Russian Journal of Applied Chemistry》2020,93(7):1083-1089
Russian Journal of Applied Chemistry - The process of detonation synthesis of nanodiamonds from ternary systems was developed with conversion tetryl as their main component. The dependence of the... 相似文献
12.
Postnov V. N. Mel’nikova N. A. Shul’meister G. A. Novikov A. G. Murin I. V. Zhukov A. N. 《Russian Journal of General Chemistry》2017,87(11):2754-2755
Russian Journal of General Chemistry - Nafion- and Aquivion-based composite solid polyelectrolytes containing deagglomerated detonation nanodiamonds were studied by the impedance spectroscopy... 相似文献
13.
A. P. Voznyakovskii A. O. Prokoshev A. V. Kalinin I. V. Shugalei 《Russian Journal of General Chemistry》2013,83(13):2745-2749
Composite membranes have been developed for media where accumulation of pathogenic microorganisms on the membrane surface is possible. It has been proposed to use as membrane skin layer a polymer nanocomposite modified with detonation nanodiamonds containing surface-bound dibutyltin dilaurate as biologically active substance, which should ensure self-cleaning of the membrane surface. 相似文献
14.
D. S. Volkov P. I. Semenyuk M. V. Korobov M. A. Proskurnin 《Journal of Analytical Chemistry》2012,67(10):842-850
Spectrophotometry and thermal lens spectrometry were used to study solutions of several commercial detonation nanodiamonds. It was found that the absorption spectra of solutions of all studied nanodiamond samples obey the Bouger-Lambert-Beer law, which ensures the precise determination of the total mass concentration of unknown nanodiamond solutions using a calibration plot. It was shown that the absorption spectra of nanodiamond solutions exhibit both absorption and scattering components, both significantly affecting signal formation. Conditions were proposed for the spectrophotometric determination of nanodiamonds at 250 nm (l = 1.0 cm). The detection limits were from 60 ng/mL to 2 ??g/mL, depending on the nanodiamond type. Limits of detection of SDND nanodiamonds by spectrophotometry and thermal lens spectrometry were calculated for identical conditions of sample preparation and measurements (488 nm, l = 1.0 cm). These were 10 and 0.6 ??g/mL for spectrophotometry and thermal lens spectrometry, respectively (power of excitation radiation 150 mW). 相似文献
15.
Ammonia borane (AB) is used as a combustion agent to improve the properties of high explosives. The detonation velocity (Dv) and detonation pressure (P) of raw high explosives and of samples containing AB were calculated and compared. The detonation properties, impact sensitivities, thermal sensitivities, and thermal decomposition characteristics of high explosives containing AB were also measured. The results indicated that when the AB content was 20 wt‐%, the optimal detonation velocity and detonation pressure were achieved. Both the detonation velocity and detonation pressure of the high explosives containing AB were clearly increased compared with those of the raw high explosives. Moreover, the detonation velocities of high explosives containing AB were 7078 to 7423 m · s–1 and their density ranged from 1.570 to 1.589 g · cm–3. The detonation pressure ranged from 34.5 to 37 GPa and the average heat of detonation was 6688 J · g–1. Furthermore, the impact and thermal sensitivities were 170 cm and 613 K, respectively, whereas a slight change occurred in the thermal decomposition characteristics. These results suggest that AB can serve as a powerful combustible agent in energetic materials and improve the detonation properties and sensitivities of high explosives. 相似文献
16.
《Mendeleev Communications》2022,32(2):143-151
This survey describes recent achievements in creating a new type of materials – nanodiamonds grafted with atoms of transition metals. Structural features of some selected chelate complexes studied by density functional theory, their scope and limitations as well as possible applications are discussed. Using the example of copper ions, their location relative to subsurface defects of detonation diamond is investigated by the method of electron paramagnetic resonance (EPR). 相似文献
17.
Yong Suk Choi Jong-Yun Kim Suk Bon Yoon Kyuseok Song Young Jin Kim 《Microchemical Journal》2011,99(2):332-338
A wavelength-dispersive X-ray fluorescence (WDXRF) technique that uses the scattered radiation of the X-ray tube lines and the fluorescence radiation of an element present in a powder sample is proposed as a non-destructive method for the determination of the water content in silica powder. Although direct X-ray fluorescence analysis of water using WDXRF is not adequate for the quantitative determination of water in powder, due to the very low fluorescence yield for hydrogen and oxygen, the fluorescence signal of silicon (Si) in silica powder is attenuated by water, and is shown to decrease in proportion to the water content in silica powder. In addition, it is demonstrated that the Compton- and Rayleigh-scattering of the X-ray tube lines is proportional to the water content. The coefficients of determination, R2, of the linear regression equations obtained from the calibration curves for all individual scattered radiations and for the fluorescence radiation of Si were > 0.90. The sum of the peak intensities of the four scattering signals, i.e. the Rayleigh-scattered Rh K–L2,3 and Rh K–M2,3 lines, and Compton-scattered Rh K–L2,3 and Rh K–M2,3 lines, also showed fairly good linearity and sensitivity over a very wide range of water content from 0 wt.% to 61.5 wt.%. However, porosity had a significant effect on the X-ray signal at low water content, in the range from 0 wt.% to 7.5 wt.%, where the sensitivity for the silica nanopowder with well-defined mesopores (~ 3 nm in diameter) decreased to 0.40 kcps/wt.%, from 0.99 kcps/wt.% for the non-porous silica nanopowder. The use of the Si fluorescence signal along with the scattered radiation of the X-ray tube lines expands the applicability of conventional XRF spectrometers to the quantitative determination of water content in silica powder. 相似文献
18.
Dr. Chunlin He Jiaheng Zhang Prof. Dr. Jean'ne M Shreeve 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(23):7503-7509
Fifteen iodo compounds and six iodyl compounds with an iodine content between 45.3 and 89.0 % were prepared. The mono, di, and triiodyl compounds were obtained from the corresponding iodo compound by employing Oxone. All the compounds were characterized by IR, 1H and 13C NMR, elemental analysis, and differential scanning calorimetry (DSC). The impact sensitivity was measured by using BAM (Bundesamt für Materialforschung) methodology. Based on the calculated heats of formation and experimental densities, the detonation properties and detonation products were predicted by employing Cheetah 6.0. A total percentage of iodine‐containing species in wt % (I2, HI, and I in gas phase) ranged from 46.7 ( 21 ) to 88.94 % ( 11 ) was found in the detonation products. The high concentration and easy accessibility of iodine and/or iodine‐containing species is very important in developing materials suitable as Agent Defeat Weapons (ADWs). 相似文献
19.
M. Kodama Junji Nakamura Takahiro Miyata Hiroyuki Aoki 《Journal of Thermal Analysis and Calorimetry》1998,51(1):91-104
Variation of the thermotropic behaviour of both lipid assemblies and associated water molecules with an increase in water
content was investigated for negatively charged phosphatidyl-glycerol (PG)-water system up to 90 wt.% water by DSC. The number
of water molecules existing in interbilayer regions of the present gel phase was estimated from a deconvolution analysis of
ice-melting DSC curves. On the basis of a result of the calorimetric analysis, a water-distribution diagram was constructed
over the water content range from 0 to 90 wt.%. The diagram presented a continuous incorporation of interlamellar water up
to 90 wt.% water, related to unilamellar-vesicle forming properties of charged lipids. Furthermore, similarly to a result
for neutral lipid systems previously reported by us, the present diagram also showed the existence of a specific water content
region (i.e., pre-region) where a structural change of planar to curved bilayers for multilamellar structures proceeds with
the aid of bulk-like water before finally reaching unilamellar vesicles. 相似文献
20.
E. A. Veretennikov I. V. Tselinskii M. V. Veretennikova 《Russian Journal of Applied Chemistry》2018,91(2):220-224
A qualitative and quantitative influence exerted by addition of detonation nanodiamonds on the formation selectivity of mononitrotoluene isomers in the heterophase nitration of toluene with a sulfuric-nitric acid mixture having low nitration activity was found. It is shown that the isomer ratio of the ortho-/paramononitrotoluenes can be varied within the range 1.00–2.7 at a temperature of 50°C by changing the stirring intensity within the range 300–5000 rpm. It was found that the strongest influence on the ortho-/para-ratio of the mononitrotoluene isomers is exerted by nanodiamonds having surface chemically modified via oxidation with a mixture of concentrated nitric and sulfuric acids. 相似文献