Papers by Keyword: Nanodiamond

Abstract: Operation of elastomeric materials in the extreme climatic conditions of the North is a complex and expensive, since not always existing materials can provide the required level of low-temperature characteristics (down to-60 ° C). This leads to failure of machines and mechanisms, equipment downtime, additional costs for repair or replacement of rubber parts. The need for such materials is continuously growing due to the intensive development of the northern territories, the need to develop new mineral deposits and development of offshore hydrocarbon production. Propylene oxide rubber (T_g = -73 °С) and epichlorohydrin rubber Hydrin T6000 (T_g = -60 °С) have unique frost resistance, but there is a need to improve aggressive media resistance, wear resistance and relaxation properties (the ability to restore its shape after relieving the load). For the modification of rubbers, additives of both organic and inorganic nature were chosen: ultrafine polytetrafluoroethylene, single-walled and multi-walled carbon nanotubes, nanodiamond-containing carbon charge obtained by detonation synthesis, shungite, natural zeolites and bentonite clays. The operating properties of rubber were studied in accordance with standard methods. The structure of the obtained materials was studied by means of DSC, XRD, electron and atomic force microscopy. All developed materials are recommended for use in various industries (oil and gas, road, rail) in the Arctic regions with extreme climatic conditions.

Abstract: In this work we report the potential of nanostructured fibers consisting of nanodiamond particles (NDPs) and fish gelatin (FG) to modulate the mechanical properties of fish gelatin hydrogels, in the aim of developing bioinspired ECM analogues. NDPS-loaded FG fibers were obtained by electrospinning. The biocomposites were obtained through the enzymatic crosslinking of gelatin in the presence of NDPs-loaded FG fibers. The mechanical behavior was assessed at different preparative stages (precursors, fibrous mesh, biocomposite scaffolds).

Abstract: nanoDiamond was mixed with ethylic cellulose and other Material to form to paste. A series of sol-gel nanoDiamond film with different proportions were designed test intentionally. nanoDiamond film was fabricated on Aluminum substrates using two-steps sintering process. The moving terminal of the variable super-capacitor was the shaft which throughout each of monolithic capacitor plate. The low melting point glass powder possesses giant permittivity, low dielectric loss, good thermal stability and dielectric constant in a wide temperature range which applied very broad prospects in microelectronics. The low melting point glass powder was mixed with carboxymethyl cellulose and deionized water to paste. The low melting point glass powder insulation thick-film was fixed on nanoDiamond film .In this paper, the insulation thick-film preparation: sintering at 578K to 588K and keeping 11.5 h to 12.5 h. A variable super-capacitor was designed based on nanoDiamond film electrode and low melting point glass powder insulation thick. Insulation thickness was prepared on uniform nanodiamond film to increase insulation super-capacitor between the two plates.

Abstract: In this paper we have proposed a modified expression for the fitting M(T) data in Co-P powders with nanocorundum and nanodiamond precipitates. The expression for M(T) takes into account the effects from both thermal magnetic excitations – Bloch’s T ^3/2 law and temperature dependence of the magnetic anisotropy. The fitting parameters are spontaneous magnetization at absolute zero temperature, Bloch constant and order of magnetic anisotropy constant. The obtained Bloch constant is in good agreement with literature data. The order of magnetic anisotropy constant is found to be about 3 that is surprising result and supposedly comes from multiphase nature of the investigated Co-P powder.

Abstract: Magnetorheological finishing (MRF) is an advanced machining technology can achieve high efficiency and smoother surfaces. This study discusses the material removal mechanism of MRF, and proposes a kind of magnetorheological fluid with the nano-diamond abrasives. A series of experiments on the BK7 optical glass were conducted to investigate effects of the concentration of nano-diamond abrasives on surface quality and removal efficiency.

Abstract: The test of nano-diamond cathode field emission characteristics was conducted by changing the vacuum, the influence of vacuum change on nano-diamond field emission characteristics was also explored. It was found that under the condition of low vacuum, nano-diamond field emission turn-on field is relatively high, as the vacuum increases, turn-on field decreases gradually, and current density increases. When system vacuum reaches to above 10^-4 Pa level, turn-on field becomes stable, the stable value is 4.5 V/μm; and current density also becomes stable, the stable value is 117 μA/cm²; the luminescence effect of anode which is 200μm distant from the cathode in the vacuum chamber also becomes stable. Results show that 10^-4 Pa is system vacuum limit parameter of stable working of field emission display, the experiment provides a basis to the design and manufacture of nano-diamond field emission display.

Abstract: Cathode samples of titanium-based nanodiamond field emission were prepared by electrophoresis dispersed solutions in different formulas. Observe the surface and structure of the coating by using metaloscope, microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD); Test the field emission characteristic after annealing; Analyze the relation between the samples’ light photos and the uniformity of coating; Discuss the mechanism of the improved field emission characteristic after annealing. Under the same conditions the surface uniformity of diamond coating prepared by isobutyl alcohol is best,it is the minimum threshold electric field emission, 5.5 V/μm, the current density can reach to 85μA/cm² at the field of 15V/μm. Field emission characteristic and luminescence could be best after annealing.

Abstract: The synthesis of nanodiamonds by pulsed-laser ablation in liquid (PLAL) is an attractive research field in developing well-dispersed fluorescent nanodiamonds for bioimaging and life science. However, nanodiamonds are quite different from their widely pursued carbon allotropes both in synthesis conditions and physical properties. It is a great challenge to synthesize metastable phase nanodiamonds that prefer high temperature and high pressure. Despite the progress in the synthesis of nanodiamond by pulsed-laser ablation of graphite target using different laser power densities under room conditions, the transformation from graphite to nanodiamonds are not yet well explained. In order to have a better understanding to the formation of metastable nanodiamonds upon PLAL, the formation of nanodiamond has been elucidated from both the aspects of thermodynamics and kinetics. Due to low laser intensity and long wavelength, synthesis of nanodiamonds is the result of high cooling velocity of high-pressure and high-temperature carbon vapor condensation formed under laser vaporization of graphite particles. When diamond nuclei grow into the right size, they cannot increase and the graphite nucleation begins to form and grow on the diamond at given conditions due to long pulse width for ms-pulsed laser. In fact, the diamond particles enwrapped several layers of graphite have obtained. Moreover, the reasons related 3~6nm diamonds prepared by this new process and having narrow size distribution are also discussed.

Abstract: Starch-based nanocomposite films were fabricated by the incorporation of different amounts of nanodiamond (ND) particles. These films were characterized by SEM, FT-IR, TGA, tensile testing and water vapor permeability measurement. It was observed that at low loadings, ND dispersed well in starch matrix. However, as the loading amount increased, aggregates as large as several micrometers appeared. The physical blending of ND with starch didnt change the thermal degradation mechanisms of starch films, only increased the char residues. As the ND loading increased, the tensile strength of composite films increased but the elongation at break decreased. However, the water vapor permeability increased as the loading of ND increased due to the increased microspores in films. With further modifications, ND may be considered as a novel of biocompatible nanofillers for reinforcement of biopolymers for food packaging applications.

Abstract: CP2 polyimide (prepd. from 6FDA and 1,3-bis (3-aminophenoxy) benzene) was blended with (1-50 wt.%) detonation nanodiamonds (DND, pristine, acetone-washed, and 4-(2,4,6-trimethylphenoxy) benzoic acid-functionalized), and the blends were evaluated as thin films for its potential utility in high-energy-density capacitors that would have stable dielectric properties over a wide temperature range (-55 to 300°C) and at frequencies up to or greater than 100 kHz. Both the dielectric storage and loss increased substantially with DND content. Surface functionalization (with the above benzoic acid derivative) significantly reduced the dielectric loss, while the use of acetone-washed DNDs had no effect on the dielectric loss. DND was also blended with CP2 via in-situ polymerization and found to have little effect on the dielectric properties.