Nitrogen trifluoride NF3 NF3 is a colorless, toxic gas that is highly irritating and corrosive. It is an important compound with a wide range of applications in industry, military and scientific research. This article will introduce the properties, preparation methods, application fields and safety protection of nitrogen trifluoride in detail.
1. Properties of nitrogen trifluoride.
Nitrogen trifluoride is an inorganic compound with the chemical formula NF3, which is a colorless, toxic gas with strong irritation and corrosiveness.
1.Molecular weight: 71002
2.Melting point (101.)325kpa）：-206.79
3.Boiling point (101.)325kpa）：-129.0 degrees Celsius.
4.Liquid density (-129, 101.)325kpa）：1540kg/m3
5.Gas density (20, 101.)325kpa）：2.96kg/m3
6.Relative density (gas, air = 1, 20, 101325kpa）：2.46
7.Specific volume (21.)1℃，101.325kpa）：0.3371m3/kg
8.Gas-liquid volume ratio (15, 100kpa): 520L l
9.Critical temperature: -393℃
10.Critical pressure: 4530kpa
11.Critical density: 522kg m3
12.Critical compressibility factor: 0317
13.Heat of fusion (-209.)79℃，101.325kpa）：5.61kj/kg
14.Heat of gasification (-129, 101.)325kpa）：163.29kj/kg
15.Specific heat capacity (gas, 25, 101.)325kpa）：cp=751.68j/（kg·k）
16.Vapor pressure (-171): 1333kpa
17. （100℃）：470kpa
18. （60℃）：2200kpa
19.Viscosity (gas, 25, 101.)325kpa）：0.0183mpa·s
20.Refractive index: 10004416
2. Preparation method of nitrogen trifluoride.
At present, the main methods for preparing nitrogen trifluoride are chemical method and electrolysis method. The chemical method is to prepare NF3 gas by chemical reaction, and the commonly used reactants are NF4NO3, NH4F, N2F2, etc. The chemical method is simple to operate, but the prepared NF3 gas has low purity, and post-processing is required to obtain high-purity NF3. The electrolysis method is to prepare NF3 gas by electrolysis of molten salts or metal oxides, and the commonly used electrolytes are KF, NAF, etc. The electrolysis method can produce high-purity NF3 gas, but the energy consumption is high, and it is not suitable for large-scale production.
3. Application fields of nitrogen trifluoride.
As an important compound, nitrogen trifluoride has a wide range of applications in industrial, military and scientific research fields. The following are the main application areas of nitrogen trifluoride:
1.Plasma etching: In the microelectronics industry, plasma etching has become an important method for the preparation of microelectronic devices. As an important plasma etching agent, nitrogen trifluoride can be used for etching of silicon, silicon dioxide, silicon nitride and other materials.
2.High-energy fuels: Nitrogen trifluoride can react with other fuels, such as hydrogen, to produce large amounts of energy, so it can be used as a high-energy fuel.
3.Rocket propellant: In rocket propellant, nitrogen trifluoride can act as an important oxidizing agent, reacting with fuel to produce a large amount of energy to propel the rocket to flight.
4.Electronic refrigeration: Nitrogen trifluoride is also widely used in the field of electronic refrigeration. By taking advantage of the high vapor pressure and low thermal conductivity of nitrogen trifluoride at room temperature, the heat generated by electronic devices can be quickly discharged and rapid cooling of electronic devices can be realized.
5.Chemical vapor deposition: In chemical vapor deposition, nitrogen trifluoride can be used as one of the reactants for the preparation of nitrides, fluoride and other materials.
6.Nuclear industry: In the nuclear industry, nitrogen trifluoride is used to produce nuclear fuel and nuclear control rods.
7.Scientific research field: Nitrogen trifluoride is also widely used in scientific research, such as for the study of plasma physics and chemical reaction kinetics.
Fourth, the safety protection of nitrogen trifluoride.
Since nitrogen trifluoride is highly irritating and corrosive, safety precautions need to be taken during use. The following are the safety precautions for nitrogen trifluoride:
1.Wear protective clothing and gloves: When exposed to nitrogen trifluoride, protective clothing and gloves should be worn to avoid **contact and eye contact.
2.Maintain good ventilation: When using nitrogen trifluoride, good ventilation should be maintained to reduce the concentration of nitrogen trifluoride in the air.
3.Avoid contact with water: Nitrogen trifluoride reacts violently with water, producing large amounts of heat and toxic corrosive gases. Therefore, contact with water should be avoided during use.
4.Storage and handling: Nitrogen trifluoride should be stored in a cool, dry and well-ventilated place, away from fire and heat sources. Contact with organic matter should be avoided during use to avoid violent reactions. Exhaust gases should be treated by special treatment devices to avoid harm to the environment and human health.