Detonation nanodiamond (DND), also known as ultradispersed diamond (UDD), is

diamond Diamond is a Allotropes of carbon, solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Diamond is tasteless, odourless, strong, brittle solid, colourless in pure form, a poor conductor of e ...

that originates from a

detonation Detonation () is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations propagate supersonically through shock waves with ...

. When an oxygen-deficient explosive mixture of

TNT Troponin T (shortened TnT or TropT) is a part of the troponin complex, which are proteins integral to the contraction of skeletal and heart muscles. They are expressed in skeletal and cardiac myocytes. Troponin T binds to tropomyosin and helps ...

RDX RDX (Research Department Explosive or Royal Demolition Explosive) or hexogen, among other names, is an organic compound with the formula (CH2N2O2)3. It is white, odorless, and tasteless, widely used as an explosive. Chemically, it is classified ...

is detonated in a closed chamber, diamond particles with a diameter of are formed at the front of the detonation wave in the span of several microseconds.

Properties

The diamond yield after detonation crucially depends on the synthesis condition and especially on the heat capacity of the cooling medium in the detonation chamber (water, air, CO₂, etc.). The higher the cooling capacity, the larger the diamond yield, which can reach 90%. After the synthesis, diamond is extracted from the soot using high-temperature high-pressure (

autoclave An autoclave is a machine used to carry out industrial and scientific processes requiring elevated temperature and pressure in relation to ambient pressure and/or temperature. Autoclaves are used before surgical procedures to perform steriliza ...

) boiling in acid for a long period (). The boiling removes most of the metal contamination, originating from the chamber materials, and non-diamond carbon. Various measurements, including

X-ray diffraction X-ray diffraction is a generic term for phenomena associated with changes in the direction of X-ray beams due to interactions with the electrons around atoms. It occurs due to elastic scattering, when there is no change in the energy of the waves. ...

and high-resolution transmission electron microscopy, revealed that the size of the diamond grains in the soot is distributed around 5 nm. The grains are unstable with respect to aggregation and spontaneously form micrometre-sized clusters (see figure above). The adhesion is strong and contacts between a few nano-grains can hold a micrometre-sized cluster attached to a substrate. Nanosized diamond has extremely large relative surface area. As a result, its surface spontaneously attaches water and hydrocarbon molecules from the ambient atmosphere. However, clean nanodiamond surface can be obtained with appropriate handling. The detonation nanodiamond grains mostly have

diamond cubic In crystallography, the diamond cubic crystal structure is a repeating pattern of 8 atoms that certain materials may adopt as they solidify. While the first known example was diamond, other elements in group 14 also adopt this structure, in ...

lattice and are structurally imperfect. The major defects are multiple twins, as suggested by high-resolution transmission electron microscopy. Despite the carbon source for the diamond synthesis—TNT/RDX explosive mixture—being rich in nitrogen, concentration of paramagnetic nitrogen inside diamond grains is below one part per million (ppm). Paramagnetic nitrogen (neutral nitrogen atoms substituting for carbon in the diamond lattice) is the major form of nitrogen in diamond, and thus the nitrogen content in DND is probably very low.

Alternative synthesis methods

Diamond nanocrystals can also be synthesized from a suspension of graphite in organic liquid at atmospheric pressure and room temperature using ultrasonic cavitation. The yield is approximately 10%. The cost of nanodiamonds produced by this method are estimated to be competitive with the

HPHT A synthetic diamond or laboratory-grown diamond (LGD), also called a lab-grown, laboratory-created, man-made, artisan-created, artificial, or cultured diamond, is a diamond that is produced in a controlled technological process, in contrast to ...

process. An alternative synthesis technique is irradiation of graphite by high-energy laser pulses. The structure and particle size of the obtained diamond is rather similar to that obtained in explosion. In particular, many particles exhibit multiple twinning. A research group from

Case Western Reserve University Case Western Reserve University (CWRU) is a Private university, private research university in Cleveland, Ohio, United States. It was established in 1967 by a merger between Western Reserve University and the Case Institute of Technology. Case ...

produced nanodiamonds 2–5 nm in size at near-ambient conditions by a microplasma process. The nanodiamonds are formed directly from a gas and require no surface to grow on.

Applications

Commercial products based on nanodiamonds are available for the following applications: #

Lapping Lapping is a machining process in which two surfaces are rubbed together with an abrasive between them, by hand movement or using a machine. Lapping often follows other subtractive processes with more aggressive material removal as a first ste ...

and

polishing Polishing is the process of creating a smooth and shiny surface by rubbing it or by applying a chemical treatment, leaving a clean surface with a significant specular reflection (still limited by the index of refraction of the material accordi ...

(e.g. Sufipol); #

Additives Additive may refer to: Mathematics * Additive function, a function in number theory * Additive map, a function that preserves the addition operation * Additive set-function see Sigma additivity * Additive category, a preadditive category with fin ...

to engine oils (e.g. ADDO); # Dry lubricants for metal industry (Drawing of W-, Mo-, V-, Rh-wires); # Reinforcing fillers for

plastic Plastics are a wide range of synthetic polymers, synthetic or Semisynthesis, semisynthetic materials composed primarily of Polymer, polymers. Their defining characteristic, Plasticity (physics), plasticity, allows them to be Injection moulding ...

and

rubber Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Types of polyisoprene ...

, to modify the mechanical and thermal properties; # Thermal fillers for

and

, to create thermally conductive but electrically insulating materials for electronics) ; # Additives to

electroplating Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the redox, reduction of cations of that metal by means of a direct current, direct electric cur ...

electrolyte An electrolyte is a substance that conducts electricity through the movement of ions, but not through the movement of electrons. This includes most soluble Salt (chemistry), salts, acids, and Base (chemistry), bases, dissolved in a polar solven ...

(e.g. DiamoSilb, DiamoChrom, Carbodeon uDiamond) # Refined Diamonds added to ceramic coatings for paint (e.g. C6 Ceramics );

Use in medicine

Nanomaterials can shuttle chemotherapy drugs to cells without producing the negative effects of today's delivery agents. Clusters of the nanodiamonds surround the drugs ensuring that they remain separated from healthy cells, preventing unnecessary damage; upon reaching the intended targets, the drugs are released into the cancer cells. The leftover diamonds, hundreds of thousands of which could fit into the eye of a needle, do not induce inflammation in cells once they have done their job.

Ig Nobel 2012 Peace Prize

In 2012 the SKN Company was awarded the Ig Nobel Peace Prize for converting old Russian ammunition into nanodiamonds.The 2012 Ig Nobel Prize Winners
improbable.com

References

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External links

* http://pubs.acs.org/cgi-bin/sample.cgi/jpcbfk/asap/pdf/jp066387v.pdf * http://www.udayton.edu/News/Article/?contentId=2234 * http://research.ncl.ac.uk/nanoscale/research/nanodiamond.html Nanodiamond research at

Newcastle University Newcastle University (legally the University of Newcastle upon Tyne) is a public research university based in Newcastle upon Tyne, England. It has overseas campuses in Singapore and Malaysia. The university is a red brick university and a mem ...

* http://www.ioffe.rssi.ru/nanodiamond/ Ioffe Physico-Technical Institute of the Russian Academy * http://www.cnn.com/2007/TECH/science/10/19/nanodiamonds.drugs/index.html * http://www.carbodeon.com * http://www.plasmachem.de/overview-powders.html#diamond Synthetic diamond Carbon nanoparticles Russian inventions Soviet inventions Diamond industry in the Soviet Union