Fluorine is a non-metallic chemical element with the chemical symbol F and atomic number 9. Fluorine is one of the halogen elements, belonging to the periodic VII.A group, which is located in the second cycle in the periodic table. The element of fluorine is F, which is a pale yellow and highly toxic gas. Fluorine gas is very corrosive, the chemical properties are extremely active, is one of the most oxidizing substances, and can even react with some inert gases under certain conditions. Fluorine is a key element in special plastics, rubber and freezers (fluorochlorine). Due to the special chemical properties of fluorine, fluorine chemistry has an important position in the history of chemical development.
Elemental fluorine
As early as 1529, the German mineralogist Agrikla recorded that miners had used fluorite (a fluorine-containing ore) as a casting flux for steelmaking.
Fluorite is also known as fluorite. One of the more common minerals in nature can coexist with many other minerals, and is produced in many parts of the world, with 5 effective varieties. Isometric crystal system, the main component is calcium fluoride (CaF). Crystals are octahedral and cubic. The crystal is glassy luster, bright and changeable in color, brittle, Mohs hardness of 4, melting point 1360 °C, with fully cleavage properties. Some samples emit light under conditions of friction, heating, ultraviolet radiation, etc.
The mineral comes from volcanic magma, in the magma cooling process, the gas aqueous solution separated by the magma contains fluorine, in the process of the solution rising along the fissure, the fluorine ions in the gas-aqueous solution combine with the calcium ions in the surrounding rocks to form calcium fluoride, and after cooling the crystallization, fluorite is formed.
Fluorite Source: Baidu Encyclopedia
In 1670, the German glassman Schwahad occasionally came into contact with fluorite with sulfuric acid, producing a gas that cast a mist over the glasses he wore, which he realized could corrode glass. So he used wax to protect some parts of the glass, so that other parts were corroded by this gas, so that the surface of the glass formed a pattern. The patterned glass was appreciated by the royal court, and this technique of using hydrogen fluoride to etch the glass made him a lot of money.
In 1780, the Swedish chemist Carl Wilheim Scheler was fascinated by this phenomenon, imagining that the gas produced by fluorite's contact with sulfuric acid might contain some unknown, more reactive element. To this end, he conducted this reaction experiment several times. Due to the lack of chemical testing methods at that time, chemists often used the method of sniffing and tasting to identify, resulting in his premature death due to poisoning at the age of 43. Persistence leads chemists to pursue knowledge one after another.
Karl Wilheim Scheler
In 1836, the Irish Knox brothers attempted to react chlorine with mercury fluoride to produce elemental fluoride without success, but they were poisoned and suffered from long-term illness. Belgian chemist Lloyd then repeated the experiment, and the result was that he was also killed by hydrogen fluoride poisoning.
Fleming, a student at Lloyd,000, summed up the experience of his predecessors' failures, arguing that fluorine is very active and difficult to succeed with chemical methods. In 1885, he experimented with the electrolysis methods that were already in place, but the dry gas hydrogen fluoride did not conduct electricity, and his experiments failed, but he accumulated a lot of experience.
The research was passed on to Fleming's student Henry Moissan (1852-1907), who continued to work on the subject. The young Moissan saw that the research topic of preparing elemental fluoride had overwhelmed so many chemists, and instead of being discouraged, he made a great determination to overcome this difficulty. Mosan himself designed a platinum U-shaped tube device, on the platinum electrode to electrolyze the current "anhydrous hydrofluoric acid", in order to prevent the formation of high-temperature gas corrosion of the container, but also the use of refrigerant for the experimental device to cool, the resulting yellow gas is his dream of fluorine.
Henry Moissan
Moissan was the first chemist to produce many new fluorides, preparing gaseous fluoromethane, fluoroethane, isobutyl fluorine. In 1890, many fluorocarbons were prepared by the reaction of carbon with fluorine, the most notable of which was tetrafluoromethane CF, which was prepared by using the action of fluorine with methane or chloroform or carbon tetrachloride, with a boiling point of only -15 °C. Moissan's work arguably made Moissan a pioneer in the twentieth century in synthesizing a range of fluorocarbons (Freon) that act as highly effective refrigerants.
In 1900, a gaseous sulfur hexafluoride was prepared, which is chemically very similar to nitrogen, and does not decompose when heated to a relatively high temperature, nor does it react with molten alkali. Due to the inertness and chemical stability of sulfur hexafluoride, it has become an excellent gas insulation material. He also synthesized platinum, alkaline earth metals, iridium, magnesium fluoride, iodine pentafluoride and nitroyl fluoride. He compiled the results of his research on fluorine into a book called "Fluorine and Its Compounds", which is an important material for the study of the preparation and properties of fluorine and its compounds.
Moissan found fluorine in the device and his Nobel Prize certificate
Henry Mossan "knew that there were tigers in the mountains, preferring to go to the tiger mountains", and in order to dedicate himself to science, he was poisoned 4 times in experiments. For this he was awarded the 1906 Nobel Prize in Chemistry. Because of the serious damage to his health, he died at the age of 54, the second year after winning the award.
The discovery of fluorine elements has been more than 100 years, and many fluorine-containing compounds have made significant contributions to human life and production, such as the excellent performance of PTFE is an indispensable material for atomic energy and aerospace technology, the refrigerant Freon, fluorine-containing fibers, coatings, anti-cancer agents, the electrolyte lithium hexafluorophosphate in lithium-ion batteries, etc., and the fluorine elements in them have played an important role. We should have a deep respect for the pioneers of fluorine chemistry led by Mosan.
Synthesized from "Revelation of Scientific and Technological Innovation: Anecdotes of Innovation and Invention Masters", Baidu Encyclopedia
Book Author: Jin Yong
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