Application of boron trifluoride BF3

Boron trifluoride is an important catalyst widely used in organic synthesis and petrochemicals, and has applications in many organic chemical reactions such as alkylation, polymerization, isomerization, addition, synthesis and decomposition. The reason why it has such a wide range of applications in catalytic reactions such as is due to the strong tendency of the boron electron layer structure to generate complexes, which are important in acidic catalysis to produce catalytically active structures. In many reactions, boron trifluoride based catalysts are more active than inorganic acid metal halides in terms of catalytic efficacy and do not cause unfavorable side reactions. As a catalyst, BF3 can be used in a variety of forms, for example, as a stand-alone gas, or with many types of inorganic and organic additives and in its complexes. BF3 and its compounds are used as curing agents in epoxy resins and also have a wide range of applications in the dyeing of polyase fibers and the manufacture of alcohol-soluble phenolic resins.

1. Organic synthesis catalyst

BF3 plays a catalytic role in many organic syntheses. For example, in the industrial production of medium molecular weight PIB, BF3 catalytic system can not only simplify the production equipment, shorten the production cycle, reduce labor intensity, and can significantly improve the yield of PIB.

2. ion boron penetration

The term "boronization" first appeared in the literature in 1917, but detailed information about the boronization treatment and the properties of the boron layer appeared more than fifty years later. Boriding, or boronizing, is an austenitic chemical heat treatment applied to ferrous and non-ferrous materials to produce a hardened layer of borides on their surfaces. The boronized layer has a hardness of up to 2000 HV and provides good wear and corrosion resistance. Because boron trifluoride is easier to operate, no need to heat on the gas path, more uniform distribution in the furnace chamber, and because of its high boron content, it is often used as the carrier gas for boron in ion boriding.

3. used as room temperature fast curing agent

BF3 is epoxy resin room temperature fast curing agent. bf3 as a curing agent must be packaged separately from the epoxy resin, with the use of the matching. Operation ratio error affects the bonding quality, the process is cumbersome. Now we choose solid material with different melting point as wrapping material, and make BF3 into micro-capsules, blocking the epoxy resin and BF3 through the capsule wall, so as to make single-component products and stable storage, and select the release temperature through the melting point of capsule material, at which the capsule material releases BF3 curing agent and mixes with epoxy resin to promote its rapid curing. And the viscosity and molecular chain length of the capsule material can be selected to improve the flexibility of the cured epoxy resin.

4. Nuclear technology field application

Boron trifluoride-10-ether complex is reacted with calcium chloride to form trimethyl borate, then hydrolyzed, and after evaporation and concentration, the high purity boric acid obtained can be used as neutron moderator in nuclear reactors.

Some complexes of BF3 are enriched with 10B in the form of 10 BF3, which can be used to separate isotopes of boron. And 10BF3 can be used as a neutron absorbing medium within a proportional neutron counter in nuclear technology and for nuclear reactor control.

5. Ion injection source for semiconductor device manufacturing process

Boron trifluoride is used as an ion injection source in the semiconductor device manufacturing process to improve the performance of semi-heterodyne devices.

When Group V atoms are doped in a crystal of Group IV silicon atoms in the periodic table, they are able to conduct electricity because of an extra free electron in the outer electron. We call the group V impurity an N-type impurity and the atom that generates the free electron a giving body. When group III atoms are doped, in contrast to the above, a hole appears due to the absence of an electron. In this hole, neighboring electrons can jump in and can move in a sequential manner. This group III impurity is called a P-type impurity, and the atom that creates the hole is called an acceptor.

Usually, phosphorus and arsenic are used as N-type impurities, and boron is used as a P-type impurity. This impurity is called dopant, and the process of adding dopant is called dopant mass. Usually, the proportion of dopant is 106-107 silicon atoms doped with 1 impurity to form a conductive region.