I. Characteristics of Nano Diamond
Diamond is the hardest substance on earth and the most valuable diamond material. Among all natural and synthetic materials, diamond has the highest hardness and thermal conductivity, the widest range of optical through the range of frequency response, the highest refractive index, the best wear-resistant properties, its acoustic properties, radiation resistance and corrosion resistance and other properties are also the best. It can be said that diamond is the most perfect functional material in the material world so far. Since diamond powder has potential application prospect in military and national economy, its preparation technology has been paid more and more attention.
Nano diamonds are spherical nano-scale materials synthesized instantaneously using TNT and RDX blasts at high pressure (200,000 atmospheres) and high temperature (3000k), with the dual properties of nano particles and super-hard materials, and are the most thermodynamically stable nano-structural units. It is the most thermodynamically stable nano-structural unit. It can be added to many materials to stabilize their existence and change the nature of the original material, constituting a brand-new nano-material. Nano diamonds are the finest diamond powder obtained by any method, which does not exist in nature and can only be synthesized by artificial methods. They have unparalleled hardness and corrosion resistance, and at the same time, due to the small grain size (can be done up to 10 nm, 1 nm is one billionth of a meter), large specific surface area and has a high physical activity and microscopic adsorption, in the solution of the problem of nanoscale assembly, can completely eliminate the interfacial tension problem, to solve the problem of agglomeration. It is suitable for the application in the field of anti-wear and friction reduction as well as the modification and enhancement of laminating materials.
II,Domestic and Foreign Development of Nano Diamonds
The production of nano diamonds are to take graphite bombardment method is completed, the traditional crushing and grinding technology functions to diamond powder processing to 200 nm, can not become a structural unit of the nanometer scale. This method is simple to operate, our country in the detonation synthesis of nanodiamond technology and application of the development of an early start, has developed a number of products, with the international advanced level.
1.national defense
(1) It has great transmittance and absorption of radar wave and infrared ultraviolet light, and can be coated on aircraft, tanks, missiles and warships for invisibility and anti-corrosion;
(2) Adding nanodiamonds to explosives can greatly increase the explosive power of the explosives.
(3) Nano diamond brush plating can be applied to the protective armor of armored vehicles and tanks, and plated into gun barrels and gun tubes.
(4) By adding nanodiamonds to fabric fibers, wear-resistant, self-cleaning, UV-resistant, and invisible fabrics can be created.
2、Lubricating materials
Nano diamond particles processed by nano assembly technology can completely eliminate interfacial tension and make them evenly and thermodynamically stable suspended in the lubricating oil, which is equivalent to placing hundreds of millions of bearing beads in the lubricating oil. When working, it can generate a never-wear diamond ball bearing structural film between the cylinder liner and piston, and change the sliding friction into rolling friction. It can also make up for worn or rough recesses, which can greatly extend the life of the engine;
3、Machinery
(1) Preparation of nano-diamond-containing nickel-plated, chromium-plated, copper-plated, zinc-plated, cobalt-phosphorus-plated and other overlaying plating solution for various cutting tools, punching, extrusion, drawing and pressing molds, gears, shafts, cylinders, cylinder liners, nozzles, and overlaying plating, which can increase abrasion resistance by 2–4 times, and increase the apparent micro-hardness by 1–4 times.
(2) Together with other metal particles, nano-diamonds can be used to produce high-strength and wear-resistant over-alloyed metals in a hydrogen environment, which can be widely used in the manufacture of engine cylinders, pistons and petroleum drills.
4、electronic
(1) Explosive bombardment method can be made of nano-diamond semiconductor materials, which has a wide band, high electron and hole mobility, bandwidth of 5.5ev, 5 times higher than the commonly used semiconductor silicon materials; hole mobility is four times that of silicon, circuit operation speed is greatly improved. Since the carriers caused by radiation do not easily accumulate on diamond semiconductors and do not affect the characteristics of the device, it is an ideal material for the production of highly reliable, radiation-resistant semiconductor devices.
(2) By doping boron and aluminum with nanodiamonds, the resistance decreased from 7.7*107 ohm-cm to 0.1-2 ohm-cm, which broadened the way for the preparation of nanodiamond semiconductor materials and electrode materials.
(3) With excellent cold cathode field emission effect, it is an ideal material for high-definition, low-energy, large-viewing-angle ultra-thin flat panel displays that can replace liquid crystals;
(4) Nano diamond film, can be used as integrated circuits, magnetic disks, magnetic heads and other high-grade protective film.
5. Laminating materials
There are many carboxyl, hydroxyl, carbonyl and other functional groups on the surface of nanodiamonds, which can easily bond with metals, rubbers, plastic polymers and fabrics. Adding a small amount of nanodiamond can make them have special affinity and wear-resistant, anti-corrosion properties.
(1) A small amount of nanodiamonds suspended in paint and sprayed on the surface of automobile can resist scratches, UV protection, non-absorption of water, self-cleaning, and improve the uniformity, firmness, and weather resistance of automobile paint. It can be coated on ships to resist sea water corrosion.
(2) Adding nanodiamonds to rubbers and polymers can greatly improve their performance. It can improve tire burst strength (from 53Mpa to 154Mpa); improve the elasticity of rubber products by 2 times, and improve abrasion resistance by 2-2.5 times; add it to fluorine rubber to make rubber devices for engines, and add it to acrylic rubber to make seals that can greatly improve the elasticity at low temperatures; and add it to epoxy resin-based polymers to improve the strength of the connection by 2-2.5 times.
(3) By adding a small amount of nano diamond powder to laminated ceramic products, the toughness can be greatly increased, brittleness can be reduced, and wear resistance can be improved.
6. Biomedical materials
Coated with Nano Diamond on surfaces such as teeth, jawbone, leg joints, etc., it is biocompatible, wear-resistant, and has a wide range of biomedical applications.
7. Other
(1) Use nano diamond powder to formulate fine polishing solution and polishing paste, which can be used for the fine polishing of ruby and sapphire jewelry and high-grade optical lenses.
(2) The extremely large specific surface area of nanodiamonds provides a strong ability to absorb and store hydrogen. It can be used as a substrate for fuel cells, which is of great use in developing new types of energy and reducing pollution.
All in all, nanodiamonds are the crystallization of modern technology with a wide range of market applications.
