Spherical nanometer-sized diamond obtained from detonation

Abstract

Ž. Ultrafine diamond UFD was synthesized under high pressure and high temperatures generated by explosive detonation. The structure, composition, surface and thermal stability of UFD were studied by use of XRD, TEM, Raman Spectroscopy, FTIR, etc. The influences of the synthesis conditions and purification conditions on the properties of UFD were analyzed. The UFD had an average size of 4᎐6 nm, commonly exhibiting a spherical shape. The highest yield was of up to 10 mass% of the explosive. Attempts were made to use UFD as an additive to metal᎐diamond sintering and as crystallite seeds of CVD diamond films. The results show that UFD can decrease the coefficient of friction of the composite by 30%, and raise the nucleation density in CVD diamond films by 2᎐3 times. ᮊ 2000 Elsevier Science S.A. All rights reserved.

Analysis of the nanodiamond particle fabricated by detonation

“…The Raman peak observed in the vicinity of 1580 cm À1 is the sp 2 structural nanographite. The Raman scattering cross-section of the nanodiamond is 1/30 of the nanographite, which indicates that there is still a small amount of sp 2 structural nanographite residue in the nanodiamond [21]. This result agrees with the XRD results that in the vicinity of 2 ¼ 20 -30 , there is a small peak corresponding to the graphite (0 0 2) surface.…”

Preparation and Behavior of Brownish, Clear Nanodiamond Colloids

“…This finding affords us access to the individual primary diamond nanoparticles and their surfaces, providing the most important step toward utilization in various applications, such as quantum dots, [13] diamonds casting/coating, and mechanical reinforcement of other materials, [14,15] as well as toward chemical functionalization of surfaces [16,17] for biological and medical applications. Here, we report the dispersion properties of de-agglutinated detonation nanodiamonds in various nonaqueous solvents, and the pH-dependent dispersion-precipitation behavior of the hydrosols, in addition to a new, facile de-agglutination method via high-power sonication.…”

Confirmation of the electrostatic self-assembly of nanodiamonds

“…Conventional HRTEM operating at medium voltage (100 -300kV) has been used in the past to characterise the structure of diamond nanoparticles [23,24]. However, due to the weak scattering power of single particles, and the effect of 120 delocalisation due to aberrations introduced by the objective lens, interpretation of such HRTEM images has been difficult.…”

“…Here, we use aberration-corrected TEM operated at 80kV to image the diamond nanoparticles, particularly in an attempt to identify their interfacial structures. The advantage of using 125 such an instrumental setup is that the aberration-corrector greatly reduces the delocalisation in HRTEM images [24], and operating at 80kV minimises the radiation damage to the sample, and increases the image contrast due to a stronger effective interaction at such accelerating voltage [25]. 130 Nevertheless, it is still expected that TEM specimen preparation and exposing the sample under electron beam characterisation of agglutinates and agglomerates is still challenging, due to the three-dimensional nature of the aggregated superstructures, the co-existence of CICI and IICI within the one sample, and the existence of more than one allotrope.…”