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1.
Structure of the dispersive medium and sedimentation resistance of suspensions of detonation nanodiamonds 总被引:1,自引:0,他引:1
A. Yu. Neverovskaya A. P. Voznyakovskii V. Yu. Dolmatov 《Physics of the Solid State》2004,46(4):662-664
The specific features of the stabilization of suspensions formed by detonation nanodiamonds in polar and nonpolar media are investigated. It is demonstrated that the polydispersity of nanodiamond particles in an aqueous medium periodically changes in an ultrasonic field. The conditions are determined under which the optimum dispersity can be maintained for a long time. A technique is devised for chemical modification of the nanodiamond surface through the grafting of organosilyl groups. This technique makes it possible to prepare finely dispersed suspensions of nanodiamonds in nonpolar organic media. A model is proposed for an aggregate that consists of detonation nanodiamond particles and is stabilized through hydrogen bonds formed by functional groups of different types. 相似文献
2.
Nanometer-sized diamond grains are commonly found in primitive chondritic meteorites, but their origin is puzzling. Using evidence from atomistic simulation, we establish a mechanism by which nanodiamonds form abundantly in space in a two-stage process involving condensation of vapor to form carbon onions followed by transformation to nanodiamond in an energetic impact. This nonequilibrium process is consistent with common environments in space and invokes the fewest assumptions of any proposed model. Accordingly, our model can explain nanodiamond formation in both presolar and solar environments. The model provides an attractive framework for understanding noble gas incorporation and explains all key features of meteoritic nanodiamond, including size, shape, and polytype. By understanding the creation of nanodiamonds, new opportunities arise for their exploitation as a powerful astrophysical probe. 相似文献
3.
The article reports techniques that we have devised for immobilizing and allocating a single nanodiamond on the electron beam (E-beam) lithography patterned semiconductor substrate. By combining the E-beam patterned smart substrate with the high throughput of a confocal microscope, we are able to overcome the limitation of the spatial resolution of optical techniques (~1 μm) to obtain the data on individual nano-object with a size range between 100 and 35 nm. We have observed a broad photoluminescence centered at about 700 nm from a single nanodiamond which is due to the defects, vacancies in the nanodiamonds, and the disordered carbon layer covered on the nanodiamond surface. We also observe red-shift in energy and broadening in linewidth of the sp3 bonding Raman peak when the size of the single nanodiamond is reduced due to the phonon-confinement effects. 相似文献
4.
Surface chemistry of nanodiamonds 总被引:2,自引:0,他引:2
I. I. Kulakova 《Physics of the Solid State》2004,46(4):636-643
The experimental data available in the literature and the results obtained by the author in research into the structure of nanodiamonds and the physicochemical and chemical properties of their surface are generalized. An account is given of the problems concerning the chemical state and modification of the nanodiamond surface in gaseous and liquid media and the infiuence of modification on the sorption and catalytic properties of nanodiamonds, their compactibility, and sintering. The similarity and difference in the behavior of nanodiamonds and diamond macrocrystals in oxidation processes are discussed. The activation energies of oxidation of nanodiamonds by different reagents are determined in the absence and presence of catalysts. 相似文献
5.
A. S. Chiganov 《Physics of the Solid State》2004,46(4):620-621
The effect of selective inhibition of nanodiamond oxidation upon heating of detonation carbon in air is used to extract nanodiamonds from the detonation products. The methods for cleaning nanodiamonds from nondiamond carbon modifications are described depending on the synthesis conditions. 相似文献
6.
G. Dantelle A. Slablab F. Lainé Ph. Bergonzo T. Gacoin J.-F. Roch 《Journal of luminescence》2010,130(9):1655-3095
Nanodiamond powders with an average size of 50 nm have been irradiated using high-energy electron beam. After annealing and chemical treatment, nanodiamond colloidal solutions were obtained and deposited on silica coverslips by spin-coating. The fluorescence of nanodiamonds was studied by confocal microscopy together with atomic force microscopy. We evaluated the proportion of luminescent nanodiamonds as a function of the irradiation duration and showed that large quantities, exceeding hundreds of mg, of luminescent nanodiamonds can be produced within 1 h of electron irradiation. 相似文献
7.
Multiscale glass fiber epoxy matrix composites containing nanodiamonds were fabricated using vacuum bagging technique. Three different loadings of nanodiamonds were incorporated in epoxy resin after their functionalization through ozone-treatment, i.e., 0.1, 0.3 and 0.5 wt%. The functionalization of nanodiamonds was confirmed by infrared spectroscopy, which improved the dispersion of nanodiamond in epoxy resin thus improving the mechanical properties. Tensile, compression, flexural and interlaminar shear properties of the composites were improved. The tensile, compression and flexural strengths improved up to 36, 56 and 30% by the addition of 0.5 wt% nanodiamonds while the corresponding moduli increased to 30, 125 and 46%, respectively. An improvement of 38% in interlaminar shear strength was observed. The microscopy of the composites was performed using optical and electron microscopy and proper impregnation of glass fibers and the absence of the agglomerates of nanodiamonds were ensured. The homogeneous dispersion of nanodiamonds and their adhering role at fiber/matrix interface improved the mechanical properties of the composites. The developed composites are ideal candidate materials for engineering applications demanding high specific mechanical properties. 相似文献
8.
Sonnefraud Y Cuche A Faklaris O Boudou JP Sauvage T Roch JF Treussart F Huant S 《Optics letters》2008,33(6):611-613
Diamond nanocrystals containing highly photoluminescent color centers are attractive, nonclassical, and near-field light sources. For near-field applications, the size of the nanocrystal is crucial, since it defines the optical resolution. Nitrogen-vacancy (NV) color centers are efficiently created by proton irradiation and annealing of a nanodiamond powder. Using near-field microscopy and photon statistics measurements, we show that nanodiamonds with sizes down to 25 nm can hold a single NV color center with bright and stable photoluminescence. 相似文献
9.
Dmitry Medvedev Dmitry Sapunov Boris Potapkin Sergey Korobtsev 《Applied Physics A: Materials Science & Processing》2012,108(2):275-281
A novel type of high voltage pulsed electric discharge in water flow in a Venturi tube is proposed. The influence of the novel discharge on sizes and properties of nanodiamond particles has been studied. Experiments were carried out in water media with purified detonation nanodiamonds made impure by non-diamond carbon material. The ability of high voltage pulsed electric discharge in water to modify nanoparticle conglomerates in water solution and to relieve spherically shaped nanodiamond conglomerates from the initial mixture with non-diamond material can be seen. Prolonged treatment of the suspension made it possible to relieve primary nanodiamond crystals from conglomerates. Formation of ordered and unordered structures from primary (3?C5 nm) nanodiamond crystals has been observed. Study of the electric discharge in water was carried out at the pressure region from atmospheric down to 0.02 atm to reproduce conditions which are typical for the discharge in the Venturi tube in liquid flow and different gap lengths. Two ??types?? of discharge behavior depending on the geometry of the discharge system and other external parameters have been observed. Characteristics that are critical for understanding the behavior of the discharge in the Venturi tube in water flow have been investigated. 相似文献
10.
Philipp Reineck Leevan Fremiot Trindade Jan Havlik Jan Stursa Ashleigh Heffernan Aaron Elbourne Antony Orth Marco Capelli Petr Cigler David A. Simpson Brant C. Gibson 《Particle & Particle Systems Characterization》2019,36(3)
Fluorescent nanodiamonds (FNDs) are vital to many emerging nanotechnological applications, from bioimaging and sensing to quantum nanophotonics. Yet, understanding and engineering the properties of fluorescent defects in nanodiamonds remain challenging. The most comprehensive study to date is presented, of the optical and physical properties of five different nanodiamond samples, in which fluorescent nitrogen‐vacancy (NV) centers are created using different fabrication techniques. The FNDs' fluorescence spectra, lifetime, and spin relaxation time (T1) are investigated via single‐particle confocal fluorescence microscopy and in ensemble measurements in solution (T1 excepted). Particle sizes and shapes are determined using scanning electron microscopy and correlated with the optical results. Statistical tests are used to explore correlations between the properties of individual particles and also analyze average results to directly compare different fabrication techniques. Spectral unmixing is used to quantify the relative NV charge‐state (NV? and NV0) contributions to the overall fluorescence. A strong variation is found and quantified in the properties of individual particles within all analyzed samples and significant differences between the different particle types. This study is an important contribution toward understanding the properties of NV centers in nanodiamonds. It motivates new approaches to the improved engineering of NV‐containing nanodiamonds for future applications. 相似文献
11.
Although production of nanowires from various materials is proving very successful, the development of diamond nanowires has been slow. However, a significant amount of successful research has been conducted regarding zero-dimensional nanodiamond crystals, which may offer a basis for the development of one-dimensional diamond nanostructures. Observations of the structural transitions between nanodiamonds into carbon onions inevitably lead to questions as to whether a similar transformation occurs in one dimension and, if so, how it may be avoided. Presented here are ab initio investigations of dehydrogenated nanodiamond crystals and analogous diamond nanowires, to examine how the additional dimension effects structural properties. 相似文献
12.
K. V. Reich 《JETP Letters》2011,94(1):22-26
The optical properties of nanodiamond suspensions have been calculated. The main supposition is that carbon dimers, which
in many aspects are analogous to Pandey chains (2 × 1) on the surface of bulk diamond, are formed on the surface of nanodiamonds
due to the surface reconstruction. All experimentally observed features of the absorption of nanodiamond suspensions have
been explained on the basis of these ideas. Whereas the diamond nucleus does not absorb light in the visible spectral range,
dimers on the surface of the diamond core absorb light in the entire range of optical wavelengths. In addition, there are
two features at energies close to 1.5 and 5 eV in their absorption spectrum. 相似文献
13.
通过电子注入的方法制备了含氮空位色心单光子源的金刚石荧光纳米颗粒. 自旋回声测试结果表明, 纳米颗粒中氮空位色心的相干时间T2很短, 介于0.86 μs至5.6 μs之间. Ramsey干涉条纹测试结果表明, 氮空位色心NV1点的退相干时间T2* 最大, 为0.7 μs, 其电子自旋共振谱可分辨的最小线宽为1.05 MHz. 并且NV1点的电子自旋共振谱可分辨氮空位色心本身的14N核自旋与 氮空位色心电子自旋之间的2.2 MHz超精细相互作用, 这对于在金刚石纳米颗粒中实现核自旋的操控和多个量子比特的门操作具有重要意义.
关键词:
纳米颗粒
氮空位色心
电子自旋 相似文献
14.
V. S. Sedov I. I. Vlasov V. G. Ralchenko A. A. Khomich V. I. Konov A. G. Fabbri G. Conte 《Bulletin of the Lebedev Physics Institute》2011,38(10):291-296
A method of controlled diamond doping, consisting in introducing a solid-state silicon source into a CVD reactor chamber is
proposed and implemented. Such an approach is tested during diamond film and isolated nanocrystallite growth on silicon, molybdenum,
sapphire, copper, and quartz substrates. The approach to nanodiamond doping with silicon during CVD synthesis, developed in
this paper, is promising for developing stable highly efficient luminescent nanodiamonds. 相似文献
15.
Recombinant apoobelin and recombinant luciferase are separated from bacterial cells of Escherichia coli with the use of detonation nanodiamonds. The application of nanodiamonds has a number of points in its favor, namely, (i) simplifies the procedures for purifying the proteins, (ii) decreases the time of their separation to 30–40 min, (iii) eliminates the necessity of using special chromatographic equipment, and (iv) makes it possible to prepare high-purity apoobelin and luciferase materials with protein yields of 35–45 and 45–60%, respectively. The possible mechanisms of interaction of protein molecules and nanodiamond particles are analyzed. 相似文献
16.
V. A. Popov A. V. Egorov S. V. Savilov V. V. Lunin A. N. Kirichenko V. N. Denisov V. D. Blank O. M. Vyaselev T. B. Sagalova 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2013,7(6):1034-1043
On the basis of the results of investigations carried out by differential scanning calorimetry, X-ray diffraction, nuclear magnetic resonance, high-resolution transmission electron microscopy, and Raman spectroscopy, a scheme for the transformation of detonation nanodiamonds (which are agglomerates of smaller particles) into onion-like carbon nanoparticles during vacuum annealing is verified. At high temperatures, the transition of an individual nanodiamond occurs in a short period of time and may proceed via an amorphous state. 相似文献
17.
E. M. Baitinger E. A. Belenkov M. M. Brzhezinskaya V. A. Greshnyakov 《Physics of the Solid State》2012,54(8):1715-1722
The experimental results of a comprehensive investigation of the structure of detonation synthesis nanodiamonds by electron microscopy methods have been presented. The morphology of diamond nanoparticles has been investigated and the microdiffraction patterns have been analyzed. The method of characteristic fast electron energy loss spectroscopy in transmission electron microscopy has been used. The local density of structural components of a nanodiamond (diamond core and fullerene-like shell) has been obtained. The shape of the shell surrounding the nanocrystal has been determined using model calculations. A hypothesis explaining the charging of the nanodiamond surface has been proposed. 相似文献
18.
The intrinsic defects- and impurities-originated photoluminescence from nanodiamond particles of various sizes (5-500 nm) were observed. Luminescence spanning from 500 nm to 800 nm can be excited with 488 nm and 532 nm wavelengths lasers without any high-energy treatment to create the defects/impurities. The luminescence is found to be particle-size and laser-wavelength dependent, suggesting different kinds of defects/impurities predominantly sustain the luminescence from nanodiamonds of different sizes. 相似文献
19.
《Applied Surface Science》2002,185(3-4):321-325
We give evidence of nanometric size (5–15 nm) crystalline diamonds in carbon thin films obtained at low substrate temperature (15 °C) under the action of low pressure (0.1–0.3 Torr) 35 kHz excited CH4/Ar (80–95%) plasmas. The decrease in Ar concentration was found to lead to higher film hardness while crystalline nanodiamonds are observed in a wide interval (1–3.5 h) of deposition times but only for very high Ar concentration (95%). The polycrystalline nanodiamond grains are found over 10–20% within an amorphous carbon matrix. It is suggested that the distribution of nanodiamond grains might be connected to the nonuniform ion energy distribution in the Ar-rich plasma generated at 35 kHz. Morphological and structural features of the deposited films were also investigated. 相似文献
20.
Nanosized diamonds obtained by detonation of explosives are the subject of active studies in several scientific and technological fields. Besides their interesting peculiarities for solid-state physics studies, their presence in various circumstellar environments has been inferred from infrared (IR) spectra. Nanodiamonds are unique materials, allowing investigation of size-dependent properties of matter. We report measurements of IR properties of detonation nanodiamonds in reflectance at room temperature and in emissivity in a dedicated setup at temperatures up to 873 K. The spectra are characterized by the presence of sharp bands due to surface-bound functional groups. Thermal desorption of oxygen-containing groups leads to corresponding spectral changes. The maximal emissivity of nanodiamond powder reaches 0.985. 相似文献