What is the difference between the use of silicon and silicon dioxide?
1γ Silicon
1. High purity monocrystalline silicon is an important semiconductor material. A small amount of IIIA group elements are doped into monocrystalline silicon to form a p-type silicon semiconductor; Doped with trace VA group elements to form n-type semiconductor. The p-n junction formed by the combination of p-type semiconductor and n-type semiconductor can be made into a solar cell to convert radiant energy into electrical energy. It is a promising material in the development of energy. In addition, widely used diodes, triodes, thyristors, field effect transistors and various integrated circuits (including chips and CPUs in people's computers) are made of silicon.
2. Cermets, important materials for space navigation. Ceramic and metal are mixed and sintered to make cermet composite material, which is high-temperature resistant, tough and can be cut. It not only inherits the respective advantages of metal and ceramic, but also makes up for their congenital defects. It can be applied to the manufacture of military weapons. The first space shuttle "Columbia" can withstand the high temperature generated by friction when traveling through the dense atmosphere at high speed. It depends on its shell made of 31000 silicon tiles.
3. Optical fiber communication, the latest modern means of communication. High transparency glass fiber can be drawn from pure silica. The laser can transmit forward through countless total reflections in the path of glass fiber, replacing the bulky cable. The optical fiber communication capacity is high. A glass fiber as thin as a hair can transmit 256 lines of telephone at the same time; Moreover, it is not subject to the interference of electricity and magnetism, is not afraid of eavesdropping, and has a high degree of confidentiality. Optical fiber communication will revolutionize human life in the 21st century.
4. Silicone organic compound with excellent performance. For example, silicone plastic is an excellent waterproof coating material. Spraying silicone on the four walls of the subway can solve the problem of water seepage once and for all. A thin layer of organosilicon plastic can be coated on the surface of ancient relics and sculptures to prevent the growth of moss and resist the wind, rain and weathering. The Monument to the People's Heroes on Tiananmen Square is made of silicone plastic, so it is always white and fresh.
5. Due to the unique structure of organic silicon, which combines the properties of inorganic materials and organic materials, it has the basic properties of low surface tension, low viscosity-temperature coefficient, high compressibility, high gas permeability, and has the excellent characteristics of high and low temperature resistance, electrical insulation, oxidation stability, weather resistance, flame retardant, water repellent, corrosion resistance, non-toxic and odorless, and physiological inertia, and is widely used in aerospace, electronics, construction, transportation, chemical industry In textile, food, light industry, medical and other industries, organosilicon is mainly used in sealing, bonding, lubrication, coating, surface activity, demoulding, defoaming, foam suppression, waterproof, moisture-proof, inert filling, etc. With the continuous growth of the quantity and variety of organosilicon, the application field has been broadened, forming a unique and important product system in the field of new chemical materials. Many varieties are irreplaceable and indispensable for other chemicals.
6. Silicon can improve the hardness of plant stems and increase the difficulty of feeding and digestion of pests. Although silicon is not an essential element in plant growth and development, it is also a necessary chemical element for plants to resist adversity and regulate the relationship between plants and other organisms.
Silicon plays an important role in improving the resistance of plants to abiotic and biological stresses, such as drought, salt stress, ultraviolet radiation, diseases and pests. Silicon can improve the resistance of rice to rice leaf roller. After applying silicon, the defense response of rice to insect feeding is rapidly improved, and silicon plays a warning role in plant defense.
When rice is attacked by pests, silicon can alert rice to quickly activate the jasmonate pathway related to stress resistance. The jasmonate signal in turn promotes the absorption of silicon. The interaction between silicon and jasmonate signal pathway affects the resistance of rice to pests.
2γ Silica
Silica is the raw material for manufacturing glass, quartz glass, water glass, optical fiber, important components of electronic industry, optical instruments, handicrafts and refractories, and is an important material for scientific research.
Uses of silica: flat glass, glass products, casting sand, glass fiber, ceramic glaze, sand blasting for rust prevention, sand for filtration, flux, refractory materials and the manufacture of Autoclaved Lightweight Concrete. Silica has a wide range of uses. Rare crystals in nature can be used to manufacture important parts, optical instruments and handicrafts of electronic industry. Silicon dioxide is an important raw material for manufacturing optical fiber. Generally pure quartz can be used to make quartz glass. The expansion coefficient of quartz glass is very small, which is equivalent to 1/18 of ordinary glass. It can withstand sharp changes in temperature and has good acid resistance (except HF). Therefore, quartz glass is often used to manufacture high-temperature resistant chemical instruments. Quartz sand is often used as glass raw material and building material.
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