Modern chemical technologies and artificial materials. Chemical technology. Fundamentals of chemical technology in domestic education

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FEDERAL EDUCATION AGENCY

VOLGA POLYTECHNICAL INSTITUTE (BRANCH) OF THE VOLGOGRAD STATE TECHNICAL UNIVERSITY

DEPARTMENT OF GENERAL CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY.

INDIVIDUAL WORK

Topic: New materials in chemistry and the possibilities of their application

Completed:

student gr. VE-111

O. V. Kuznetsova

Checked:

Ivankina. O. M.

Volzhsky, 2008

Introduction

1. Polymer materials

2. Synthetic fabrics

3. Preservation and replacement of materials

6. Optical materials

Bibliography

Introduction

Materials are substances from which various products are made: products and devices, cars and airplanes, bridges and buildings, spacecraft and microelectronic circuits, charged particle accelerators and nuclear reactors, clothes, shoes, etc. Each type of product requires its own materials with well-defined characteristics. High requirements have always been and are being made on the properties of materials.

Modern technologies make it possible to produce a wide variety of high-quality materials, however, the problem of creating new materials with better properties remains relevant to this day.

When looking for a new material with desired properties, it is important to establish its composition and structure, as well as to provide conditions for their management.

In recent decades, materials have been synthesized with amazing properties, for example, materials for thermal shields for spacecraft, high-temperature superconductors, etc. It is hardly possible to enumerate all types of modern materials. Over time, their number is constantly growing.

Many structural elements of modern aircraft are made of composite polymer materials. One of these materials, Kevlar, surpasses many materials, including the highest quality steel, in terms of an important indicator - strength / weight ratio.

1. Polymer materials

polymer synthetic fabric

Plastics are materials based on natural or synthetic polymers that can take a given shape when heated under pressure and stably retain it after cooling. In addition to the polymer, plastics can contain fillers, stabilizers, pigments and other components. Sometimes other names for plastics are used - plastics, plastics.

Polymers are built from macromolecules composed of numerous small basic molecules - monomers. The process of their formation depends on many factors, variations and combinations of which make it possible to obtain many varieties of polymer products with different properties. The main processes for the formation of macromolecules are polymerization and polycondensation.

By changing the structure of molecules and their various combinations, it is possible to synthesize plastics with desired properties. An example is the synthesis of plastics with desired properties. An example is ABS - polymer. It contains three main monomers: acrylonitrate (A), butadiene (B) and styrene (C). The first provides chemical resistance, the second provides impact resistance and the third provides hardness and ease of thermoplastic processing. The main value of these polymers is the replacement of metals in various structures.

The most promising materials with high thermal stability turned out to be aromatic and heteroaromatic structures with a strong benzene ring: polyphenylene sulfide, aromatic polyamides, fluoropolymers, etc. These materials can be operated at temperatures of 200-400 degrees. The main consumers of heat-resistant plastics are aviation and rocketry.

2. Synthetic fabrics

Since the beginning of the twentieth century. chemical technologies began to focus on the creation of new fibrous materials. To date, a variety of artificial fibers are made mainly from 4 types of chemical materials: cellulose (viscose), polyamide, polyacrylonitrile and polyesters.

The volume of production of synthetic materials for a clothing manufacturer is driven by consumer demand, which has shown a downward trend in recent years. In this regard, one of the most important tasks of chemists is to bring artificial materials closer in properties and quality to natural ones.

Today's innovations have affected the geometry of the fibers. Manufacturers of textile raw materials strive to make the yarns as thin as possible.

Hollow fibers also appeared. They resist cold better. If such a fiber in cross section is not round, but oval, then the fabric from it more easily removes sweat from the skin.

One of the varieties of synthetics is Kevlar. It is 5 times more tear-resistant than steel and is used to make bulletproof jackets. The favorite material of fashion designers - elastic - is comfortable not only in sportswear, but also in everyday suits. There is a fabric based on tiny glass balls that reflect light. Clothes made of it - good protection for those who are on the street at night.

The technology of making fabrics for the astronaut's clothes is original, which is able to protect him outside the atmosphere from the freezing cold of space and the scorching heat of the Sun. The secret of such clothes is in millions of microscopic capsules embedded in fabric or foam - a mass.

Modern fabrics often consist of multiple layers, such as metal foil, yarn and fiber, to remove perspiration.

The latest fabrics have paved the way for modern clothing technology.

3. Replacement of materials

Old materials are replaced by new ones. This usually happens in 2 cases: when there is a shortage of old material and when new material is more effective. The substitute material should have better properties. For example, plastics can be classified as substitute materials, although it is hardly possible to consider them as definitely new materials. Plastics can replace metal, wood, leather and other materials.

The problem of replacing non-ferrous metals is no less difficult. In many countries, they follow the path of economical, rational consumption. The advantages of plastics for many applications are clear: one ton of plastics in mechanical engineering saves 5 to 6 tonnes of metals. In the production of, for example, plastic screws, gear wheels, etc., the number of processing operations is reduced, and labor productivity is increased by 300-1000%. When processing metals, the material is used by 70%, and in the manufacture of plastic products - by 90-95%.

The replacement of wood began in the first half of the 20th century. First of all, plywood appeared, and later - fibreboard and particle boards. In recent decades, wood has been replaced by aluminum and plastics. Examples include toys, household items, boats, building structures, and the like. At the same time, there is a trend towards an increase in consumer demand for goods made from wood.

In the future, plastics will be replaced by composite materials, the development of which is given great attention.

4. Heavy duty and heat resistant materials

The range of materials for various purposes is constantly expanding. The last decade has created a natural - scientific base for the development of fundamentally new materials with desired properties. For example, steel containing 18% nickel, 8% cobalt and 3-5% molybdenum is characterized by high strength - the ratio of strength to density for it is several times higher than for some aluminum and titanium alloys. Its main area of application is aviation and rocketry.

The search for new high-strength aluminum alloys continues. Their density is relatively low and they are used at relatively low temperatures - up to about 320 degrees. Titanium alloys with high corrosion resistance are suitable for high temperature conditions.

Further development of powder metallurgy is underway. Compression of metal and other powders is one of the promising ways to increase the strength and improve other properties of compacted materials.

In the last decade, much attention has been paid to the development of composite materials, i.e. materials consisting of components with different properties. Such materials contain a base in which reinforcing elements are distributed: fibers, particles, etc. Composites can include glass, metal, wood, artificial substances, including plastics. The large number of possible combinations of components allows you to obtain a variety of composite materials.

When combining poly - and monocrystalline threads with polymer matrices (polyesters, phenolic and epoxy resins), materials are obtained that are not inferior in strength to steel, but they are 4 - 5 times lighter.

The material of the future will be one that will be not only super-strong, but also resistant to prolonged exposure to an aggressive environment.

The creation of heat-resistant materials is one of the most important tasks in the development of modern chemical technologies.

To date, promising methods for the manufacture of heat-resistant materials have been developed. These include: implantation of ions on any surface; plasma synthesis; melting and crystallization in the absence of gravity; spraying on polycrystalline, amorphous and crystalline surfaces using molecular beams; chemical condensation from the gas phase in a glow plasma discharge, etc.

With the use of modern technologies, for example, silicon nitride and tungsten silicide, heat-resistant materials for microelectronics, have been obtained. Silicon nitride has excellent electrical insulating properties even with a small layer thickness of less than 0.2 microns. Tungsten silicide has a very low electrical resistance. These materials are deposited in the form of a thin film on the elements of integrated circuits. The deposition is carried out by the method of plasma deposition on a less heat-resistant substrate without a noticeable change in its properties.

Of practical interest is a method for producing new ceramic materials for manufacturing, for example, an all-ceramic engine block. internal combustion. This method consists in casting a silicon-containing polymer into a mold of a given configuration, followed by heating, in which the polymer is converted into a heat-resistant and durable silicon carbide or nitride.

New technologies make it possible to synthesize more heat-resistant materials.

5. Materials with unusual properties

Nitinol is nickel - titanium alloy, which has an unusual property - to retain its original shape. Therefore, it is sometimes called the memory metal, or the metal with memory. Nitinol is able to retain its original shape even after cold forming and heat treatment. It is characterized by super - and thermoelasticity, high corrosion and erosion resistance.

Initially, nitinol products served as an advantage for military purposes - they were used to connect various pipelines in combat aircraft, to which access is limited.

A unique design using nitinol couplings was assembled six years ago in space. Mounting a relatively long motor mount traditional methods would require astronauts to stay in space for a long time, which could expose him to excessive cosmic radiation. The thread couplings made it possible to quickly and easily assemble the 14 meter mast.

The greatest benefit can be brought by the use of nitinol couplings not for solving one-time space and narrowly directed military tasks, but for national economic purposes. These are gas pipelines, oil pipelines, gas pipelines, water pipelines. Gas, oil and petrol pipelines filled with flammable gas, oil and gasoline, respectively, present an increased fire hazard, and therefore they cannot be welded during repairs, and all restoration work has to be performed using threaded connections and fasteners. This task It is much easier with the use of corrosion-resistant nitinol couplings that operate when a relatively small current is passed through them, and no open fire is required.

Nitinol clamps, couplings, spirals are used in medicine. With the help of nitinol fixators, the broken parts of the bones are more efficiently connected. Due to the shape memory, the thread sleeve is better fixed in the gum, protecting the joints from overload. Nitinol, having the ability to resiliently deform by 8-10%, smoothly perceives the load, like a living tooth, and as a result, it injures the gums less. The nitinol coil is able to restore the cross-section of a vessel affected by a particular disease in the human body.

Undoubtedly, nitinol is a promising material, and many other examples of its successful application will become known in the near future.

Liquid crystals are liquids that, like crystals, have anisotropy of properties associated with the ordered orientation of molecules. Due to the strong dependence of the properties of a liquid crystal on external influences, they find various applications in technology (in temperature sensors, indicator devices, light modulators, etc.). Today, in the world market of display technologies, liquid crystal devices are inferior only to CRTs, and in terms of energy efficiency in displays with a relatively small screen area, they have no competitors.

A liquid crystal substance consists of organic molecules with a predominantly ordered orientation in one or two directions. Such a substance has fluidity like a liquid, and the crystalline ordering of molecules is confirmed by its optical properties. There are three main types of liquid crystals: nematic, smectic and cholesteric.

One of the promising directions in the chemistry of liquid crystals is the implementation of these structures in the synthesis of polymers. Molecular ordering characteristic of nematic liquid crystals. It is this principle that underlies the production of artificial fibers with extremely high tensile strength, which can replace materials for the manufacture of aircraft fuselages, body armor, etc.

6. Optical materials

The electrical signal sent through the copper wire is gradually being replaced by a much more informative light signal propagating along the light-conducting fibers.

Improvement of technologies for the production of quartz filaments has made it possible to reduce the loss of luminous flux by about 100 times in less than ten years. Even more transparent fibers can be made from new optical materials such as fluoride glasses. Unlike conventional glasses, which are composed of a mixture of metal oxides, fluoride glasses are a mixture of metal fluorides.

Fiber optics offers tremendous opportunities for transmitting large amounts of information over long distances. Already today, many telephone exchanges, television, etc. use fiber-optic communication with success.

Modern chemical technology has played an important role not only in the development of new optical materials - optical fibers, but also in the creation of materials for optical devices for switching, amplifying and storing optical signals. Optical devices operate on new time scales for processing light signals. Modern optical devices use lithium niobate and gallium-aluminum arsenide.

Experimental studies show that organic stereoisomers, liquid crystals, and polyacetylenes have better optical properties than lithium niobate and are very promising materials for new optical devices.

7. Materials with electrical properties

At the beginning, such materials were mainly silicon and germanium single crystals with a relatively low concentration of impurities. After a while, the developers focused on single crystals of helium arsenide grown on single crystal indium phosphide substrates. Modern technology makes it possible to obtain several layers of gallium arsenide of various thicknesses with different impurity contents. Working units of lasers and laser display devices used in long-wave optical communication lines are made from gallium arsenide materials.

During the development of new semiconductor materials, the semiconducting properties of amorphous (non-crystalline) silicon were unexpectedly discovered.

By now, completely new groups of materials with electrical conductivity have been discovered. Their physical properties largely depend on the local structure and molecular bonds. Some of these materials are inorganic, others are organic.

In polymer conductors, large planar molecules serve as elements of a conducting column and form metal microcycles, which are connected to each other through covalently bound oxygen atoms. Such a chemically engineered molecule is electrically conductive, and it is a real sensation. The atoms of the metal and the group surrounding it in the planar macrocycle can be replaced and modified different ways... As a result, it is possible to obtain a polymer with desired electrical conductive properties.

The technology for manufacturing polymer conductors has already been mastered, and the number of varieties of such conductors is growing. Under the influence of certain reagents, polyparaphenylene, paraphenylene sulfide, polypyrrole, and other polymers acquire electrically conductive properties.

In some solid materials with an ionic mobile structure, the ion mobility is compared to the ion mobility in a liquid. Similar materials are used in memory devices, displays, sensors, and as electrolytes and electrodes in batteries.

When creating modern microelectronic technology and highly sensitive equipment, a variety of materials with anisotropic electrical, magnetic and optical properties are used. These properties are possessed by ionic crystals, organic molecular crystals, semiconductor and many other materials.

Modern technology makes it possible to obtain a material in the form of glass, but not with dielectric properties, but with metallic conductivity or semiconducting properties. This technology is based on the rapid freezing of a liquid, condensation of the gas phase on a very cold surface, or the implantation of ions on the surface of a solid.

Thus, with the use of modern technologies, it is possible to obtain new materials with an unusual set of properties.

8. High-temperature superconductors

Superconductors are substances that go into a superconducting state at temperatures below critical.

Many substances have superconducting properties: about half of the metals (for example, a nickel-titanium alloy with a critical temperature of 9.8 K), several hundred alloys and intermetallic compounds.

Superconductivity has also been found in polymeric substances. All this testifies to the fact that many minerals possess superconducting properties, but their critical temperature remained relatively low for a long time.

At the end of 1986. an important discovery was made: it was found that some solid compounds based on copper and oxygen go into a superconducting state at temperatures above 90K. This phenomenon is called high temperature superconductivity.

The use of refrigerants, even such as liquid xenon, inevitably leads to the complication of designs that include superconducting materials. This is one of the reasons for restraining the widespread adoption of high-temperature superconducting materials.

High-temperature conductivity, discovered over ten years ago, promised a lot of tempting prospects both in the field of fundamental science and in solving purely technical problems. The efforts of the world's leading researchers were aimed at obtaining ever new materials and studying their structure. Research continues, none of them has yet been able to solve the problem of superconductivity in general, but each helps to understand it. Discovered a lot of important and interesting substances in the crystal structure.

9. Dissociation materials of organometallic compounds

The results of recent experimental studies have shown that thermal dissociation of a number of organometallic compounds produces pure metals of various solid forms with unique properties. These organometallic compounds include:

Carbonyls - W (CO), Mo (CO), Fe (CO), Ni (CO),

Metal acetylacetonates -

Rhodium dicarbonylacetonate -

These compounds are highly volatile in the gaseous state. They decompose when heated to 100-150C. As a result of thermal dissociation, a pure metal phase can be obtained in various condensed forms: fine powders, metal whiskers, non-porous thin-film materials, cellular metals, metal fibers and paper.

Highly dispersed powders consist of small particles - up to 1 - 3 microns and are used for the production of cermets - metal compositions with oxides, nitrides, borides, obtained by powder metallurgy.

Metal vixels are whiskers with a diameter of 0.5 - 2.0 µm and a length of 5 - 50 µm. Metal whiskers are of practical interest for the synthesis of new composite materials with a metal or plastic matrix.

Non-porous thin-film materials are characterized by a high packing density of atoms. In terms of light reflection, this material approaches silver.

Cellular metals are formed during metal deposition as a result of the penetration of vapors of organometallic compounds into the pores of any material. In this way, a cellular metal structure is formed.

10. Thin-film materials for storage devices

Any electronic computer, including a personal computer, contains an information storage device - a storage device capable of accumulating and storing a large amount of information.

The manufacture of modern high-capacity magnetic drives is based on the use of thin-film materials. Thanks to the use of new magnetic materials and as a result of improving the manufacturing technology of all thin-film elements of the magnetic storage device, relatively short term the surface density of information recording has increased fivefold.

Recording with a high surface density is carried out on a medium, the working layer of which is formed from a thin-film cobalt-containing material.

A high recording density can be realized only with the help of transducers, the thin-film material of the magnetic circuit of which is characterized by a high saturation magnetic induction and high magnetic permeability. A highly sensitive thin-film element is used to reproduce the information recorded with a high density, the electrical resistance changes in a magnetic field. Such an element is called magnetoresistive. It is sprayed from a highly permeable magnetic material such as permalloy.

Thus, with the use of thin-film magnetic materials in the manufacture of high-capacity data storage devices, a rather high information recording density has already been realized. With the modernization of such storage devices and the introduction of new materials, a further increase in information density should be expected, which is very important for the development of modern technical means of recording, accumulating and storing information.

Bibliography

1.S.Kh. Karpenkov. Concepts of modern natural science. Moscow. 2001

2. Khomchenko G.P. Chemistry for university applicants. - Higher school, 1985 .-- 357 p.

3. Furmer I.E. General chemical technology. - M .: Higher school, 1987 .-- 334 p.

4. Lakhtin Yu.M., Leontyeva V.P. Materials Science. - M .: Mechanical Engineering, 1990

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Modern chemical technology

Modern chemical technology, using the achievements of natural and technical sciences, studies and develops a set of physical and chemical processes, machines and apparatus, the optimal ways of implementing these processes and managing them in the industrial production of various substances, products, materials.

The development of science and industry has led to a significant increase in the number of chemical industries. For example, now about 80 thousand different chemical products are produced on the basis of oil alone.

The growth of chemical production, on the one hand, and the development of chemical and technical sciences, on the other, made it possible to develop the theoretical foundations of chemical technological processes.

Technology of refractory non-metallic and silicate materials;

Chemical technology of synthetic biologically active substances, chemical pharmaceuticals and cosmetics;

Chemical technology of organic substances;

Polymer technology and processing;

Basic processes of chemical production and chemical cybernetics;

Chemical technology of natural energy carriers and carbon materials;

Chemical technology of inorganic substances.

Chemical technology and biotechnology includes a set of methods, methods and means of obtaining substances and creating materials using physical, physicochemical and biological processes.

CHEMICAL TECHNOLOGY:

Analysis and forecasts of the development of chemical technology;

New processes in chemical technology;

Technology of inorganic substances and materials;

Nanotechnology and nanomaterials;

Organic matter technology;

Catalytic processes;

Petrochemistry and oil refining;

Polymer and composite materials technology;

Chemical and metallurgical processes of deep processing of ore, technogenic and secondary raw materials;

Chemistry and technology of rare, trace and radioactive elements;

Reprocessing of spent nuclear fuel, disposal of nuclear waste;

Environmental problems. Creation of low-waste and closed technological schemes;

Processes and devices of chemical technology;

Technology medicines, household chemicals;

Monitoring of the natural and man-made sphere;

Chemical processing of solid fuels and natural renewable raw materials;

Economic problems of chemical technology;

Chemical cybernetics, modeling and automation of chemical production;

Toxicity problems, ensuring the safety of chemical production. Occupational Safety and Health;

Analytical control of chemical industries, product quality and certification;

Chemical technology of high molecular weight compounds

RADIATION-CHEMICAL TECHNOLOGY (RCHT) is a field of general chemical technology dedicated to the study of processes occurring under the influence of ionizing radiation (IR) and the development of methods for the safe and cost-effective use of the latter in the national economy, as well as the creation of appropriate devices (apparatus, installations).

RCT is used to obtain consumer goods and means of production, to impart improved or new operational properties to materials and finished products, to increase the efficiency of agricultural production, to solve some environmental problems, etc.

Chemistry in modern technologies

Elpatova Olga Ivanovna,

Chemistry teacher

The purpose of the work is to analyze the history of the creation of computers and show which chemical elements are used in the development of computer technologies.

Over the past several decades, computer technology has been developing along the path of an ever-increasing miniaturization of parts and an ever-increasing rise in the cost of their production. Microprocessors of the latest generations contain a huge number of transistors (10 million or more), measuring a tenth of a micron (10-7 meter). The next step towards the microworld will lead to nanometers (10-9 meter) and billions of transistors in one chip. A little more - and we will get into the range of atomic sizes, where the laws of quantum mechanics begin to operate.

Richard Feynman noted twenty years ago that the laws of physics will not prevent the reduction of the size of computing devices until "until the bits reach the size of atoms, and quantum behavior becomes dominant." Another problem indicating that modern technology for creating computers is becoming obsolete is the problem of approaching the speed limit. Thus, modern computer media are capable of containing millions of records that existing search algorithms can no longer cope with.

This has led to an increase in the productivity of computers as a whole. The starting point for all "technological breakthroughs" in computer science is discoveries in basic sciences such as physics and chemistry.

IN computing there is a periodization of the development of electronic computers. The computer belongs to one generation or another, depending on the type of the main elements used in it or on the technology of their manufacture.

Analysis of the history of the creation of computers showed that in the development of computer technologies there has been a tendency to reduce the size of key elements and increase the speed of their switching. We took as a basis the theory of five generations of computers instead of six, since we believe we are at the turn of the fourth and fifth generations.

One of the first chemical elements found in the history of computers is germanium. Germanium one of the most important elements for technical progress, since, along with silicon, germanium has become the most important semiconductor material.

By appearance germanium is not difficult to confuse with silicon. These elements are not only competitors claiming to be the main semiconductor material, but also analogues. However, despite the similarity of many technical properties, it is quite simple to distinguish a germanium ingot from a silicon one: germanium is more than twice as heavy as silicon.

Formally, a semiconductor is a substance with resistivity from thousandths to millions of ohms per cm.

The sensitivity of germanium is remarkable not only to external influences. The properties of germanium are strongly influenced by even trace amounts of impurities. The chemical nature of the impurities is no less important.

The addition of a group V element makes it possible to obtain a semiconductor with an electronic type of conductivity. This is how hydroelectric power plants are prepared (electronic germanium doped with antimony). By adding a group III element, we create a hole type of conductivity in it (most often it is GDH - hole germanium doped with gallium).

Let us recall that "holes" are places vacated by electrons that have passed to another energy level. The “apartment” vacated by the immigrant may be immediately occupied by his neighbor, but he also had his own apartment. The migrations take place one after the other, and the hole moves.

The combination of regions with electron and hole conduction formed the basis of the most important semiconductor devices - diodes and transistors.

The creation of diodes formed the basisfirst generation computersbased on vacuum tubes in the 40s. These are electric vacuum diodes and triodes, which are a glass bulb with a tungsten filament in the center.

Tungsten are usually ranked among rare metals. It differs from all other metals in its special weight, hardness and refractoriness.

At the beginning of the XX century. tungsten filament began to be used in electric bulbs: it allows you to bring the heat up to 2200 ° C and has a high luminous efficiency. And in this capacity, tungsten is absolutely irreplaceable today. The irreplaceability of tungsten in this area is explained not only by its refractoriness, but also by its plasticity. One kilogram of tungsten is drawn into a wire 3.5 km long,those. this kilogram is enough for the manufacture of filaments of 23 thousand 60-watt bulbs. It is due to this property that the global electrical industry consumes only about 100 tons of tungsten per year.

Electronic stuffing UNIVAC consisted of more than 5000 vacuum tubes. The memory on mercury flasks made it possible to store information up to one and a half kilobytes. The most notable element in the UNIVAC design was a special storage device that allowed information to be written to and read from magnetic tape. The use of a vacuum tube as the main element of a computer created many problems. Due to the fact that the height of the glass lamp is 7cm, the cars were huge. Every 7-8 minutes. one of the lamps was out of order, and since there were 15 - 20 thousand of them in the computer, it took a lot of time to find and replace the damaged lamp. In addition, they generated a huge amount of heat, and special cooling systems were required to operate the "modern" computer of the time.

The emergence of the first generation of computers was made possible by three technical innovations: electronic vacuum tubes, digital coding of information and the creation of artificial memory devices on electrostatic tubes.

In second generation computersinstead of vacuum tubes were used transistors, invented in 1948, it was a point-contact device in which three metallic "tendrils" were in contact with a bar of polycrystalline germanium. Polycrystalline germanium was obtainedby fusing indium on both sides of the hydroelectric power station plate. All areas need germanium of very high purity - physical and chemical. To achieve it, single-crystal germanium is grown: the entire ingot is one crystal.

The transistors were more reliable, durable, and had a lot of RAM.

With the invention of the transistor and the use of new technologies for storing data in memory, it became possible to significantly reduce the size of computers, make them faster and more reliable, and also significantly increase the memory capacity of computers.

Just as the advent of transistors led to the creation of the second generation of computers, the emergenceintegrated circuitsmarked new stage in the development of computing - the birthcars of the third generation.

An integrated circuit, also called a crystal, is a miniature electronic circuit etched onto the surface of a silicon crystal with an area of about 10 mm. 2 ... Until 1965, most semiconductor devices were made on a germanium base. But in subsequent years, the process of gradual displacement of germanium by itself began to develop. silicon ... This element is the second most abundant on Earth after oxygen. Not perfect, but just high-purity and ultra-pure silicon has become the most important semiconductor material. At a temperature other than absolute zero, intrinsic conductivity arises in it, and the carriers of the electric current are not only free electrons, but also the so-called holes - places left by electrons.

By introducing certain dopants into ultrapure silicon, one or another type of conductivity is created in it. The addition of elements of the third group of the Mendeleev table leads to the creation of hole conductivity, and the fifth - electronic.

Silicon semiconductor devicescompare favorably with germanium, first of all, better performance at elevated temperatures and lower reverse currents. A great advantage of silicon was the resistance of its dioxide to external influences. It was she who made it possible to create the most advanced planar technology for the production of semiconductor devices, consisting in the fact that a silicon wafer is heated in oxygen or a mixture of oxygen with water vapor, and it is covered with a protective layer of SiO 2 .

After etching the "windows" in the right places, doping impurities are introduced through them, contacts are connected here, and the device as a whole, meanwhile, is protected from external influences. For germanium, this technology is not yet possible: the stability of its dioxide is insufficient.

Under the onslaught of silicon, gallium arsenide and other semiconductors, germanium lost its position as the main semiconductor material. In 1968, the US produced many more silicon transistors than germanium ones.

A small plate of crystalline material approximately 1 mm in size 2 turns into a sophisticated electronic device, equivalent to a radio engineering unit of 50-100 or more conventional parts. It is capable of amplifying or generating signals and performing many other radio engineering functions.

The first integrated circuits (ICs) appeared in 1964. The advent of IC meant a true revolution in computing. After all, she alone is capable of replacing thousands of transistors, each of which, in turn, has already replaced 40 electronic tubes. The speed of the third-generation computer has increased 100 times, and the dimensions have significantly decreased. At the same time, semiconductor memory appears, which is still used in personal computers as operational memory.

The idea of an integrated microcircuit appeared - a silicon crystal on which miniature transistors and other elements are mounted. In the same year, the first sample of an integrated microcircuit appeared, containing five transistor elements on a germanium crystal. Scientists quickly learned to place on one integrated microcircuit, first dozens, and then hundreds or more of transistor elements. Third-generation computers ran at speeds of up to one million operations per second.

Since the mid-70s, there have been fewer and fewer fundamental innovations in computer science. Progress is mostly along the waydevelopment of what has already been invented and invented, primarily by increasing the power and miniaturization of the element base and the computers themselves.

In the early 70s. an attempt was made to find out if more than one integrated circuit could be placed on one chip. The development of microelectronics has led to the creationfourth generationcars and the emergencelarge integrated circuits... Now it is possible to place thousands of integrated circuits on a single crystal.

This made it possible to combine most of the computer's components in a single miniature part - which Intel did in 1971 with the release of the first microprocessor. It was possible to place the central processing unit of a small computer on a chip with an area of only a quarter of a square inch (1.61 cm 2 ). The era of microcomputers has begun.

Integrated circuits already contained thousands of transistors. What is the speed of a modern microcomputer? It is 10 times higher than the speed of a third-generation computer based on integrated circuits, 1000 times higher than the speed of a second-generation computer with transistors, and 100,000 times higher than the speed of a first-generation computer based on electronic tubes.

Therefore, computers with higher speed characteristics are needed. Therefore, experts around the world have tackled this problem by creating the computing system of the future. Experimental development of a quantum computer is currently underway,biocomputer, neurocomputer, optical computer, probabilistic computer of nanoelectronics, nanocomputer, nanorobots, molecular-mechanical automata, high-temperature semiconductor materials.

For a long time, everyday goods necessary for a person (food, clothing, paints) were produced by processing mainly natural raw materials of plant origin. Modern chemical technologies make it possible to synthesize from raw materials not only natural, but also of artificial origin, numerous and diverse products in their properties, which are not inferior to natural analogues. The potential for chemical transformations of natural substances is truly endless. Increasing flows of natural raw materials: oil, gas, coal, mineral salts, silicates, ore, etc. - turn into paints, varnishes, soaps, mineral fertilizers, motor fuels, plastics, artificial fibers, plant protection products, biologically active substances, medicines and various raw materials for the production of other necessary and valuable substances.

The rate of scientific and technical development of chemical technologies is growing rapidly. If in the middle of the XIX century. it took 35 years for the industrial development of the electrochemical process of aluminum production, then in the 50s of the XX century. large-scale low pressure polyethylene production was established in less than 4 years. At large enterprises in developed countries, about 25% working capital spent on research and development, the development of new technologies and materials, which allows in about 10 years to significantly update the range of products. In many countries, industrial enterprises produce about 50% of products that were not produced at all 20 years ago. At some advanced enterprises, its share reaches 75–80%.

The development of new chemicals is a laborious and costly process. For example, to find and synthesize only a few drugs suitable for industrial production, it is necessary to produce at least 4000 types of substances. For plant protection products, this figure can reach 10,000. In the recent past, in the United States, for each chemical product introduced into mass production, there were about 450 research and development projects, of which only 98 were selected for pilot production. After pilot industrial tests, only no more than 50% of the selected products found wide practical application. but practical significance the products obtained in such a complex way are so great that the costs of research and development pay off very quickly.

Thanks to the successful interaction of chemists, physicists, mathematicians, biologists, engineers and other specialists, new developments appear that have provided an impressive growth in the production of chemical products in the last decade, as evidenced by the following figures. If the total output in the world for 10 years (1950-1960) increased by about 3 times, then the volume of chemical production during the same period increased 20 times. Over a ten-year period (1961-1970), the average annual growth of industrial production in the world was 6.7%, and chemical production - 9.7%. In the 70s, the growth of chemical production, amounting to about 7%, ensured its increase by about two times. It is assumed that with such growth rates by the end of this century, the chemical industry will take the first place in terms of production.

Chemical technologies and associated industrial production cover all the most important spheres of the national economy, including various sectors of the economy. The interaction of chemical technologies and various spheres of human activity is conventionally shown in Fig. 6.1, where the notation is introduced: BUT- chemical and textile industry, pulp and paper and light industry, glass and ceramics production, production of various materials, construction, mining, metallurgy; B- mechanical engineering and instrument making, electronics and electrical engineering, communications, military affairs, agriculture and forestry, food industry, security environment, healthcare, household, media; IN- increasing labor productivity, saving materials, success in health care; G- improvement of working and living conditions, rationalization mental labor; D- health, food, clothing, rest; E- housing, culture, upbringing, education, environmental protection, defense.

Here are some examples of the application of chemical technologies. For the production of modern computers, integrated circuits are needed, the manufacturing technology of which is based on the use of silicon. However, there is no chemically pure silicon in nature. But in large quantities there is silicon dioxide in the form of sand. Chemical technology allows ordinary sand to be converted into elemental silicon. Another typical example. Road transport burns an enormous amount of fuel. What needs to be done to minimize exhaust pollution? Part of this problem is solved with the help of an automobile catalytic converter of exhaust gases. Its radical solution is provided by the use of chemical technologies, namely, chemical manipulations over the feedstock - crude oil, processed into refined products that are efficiently combusted in car engines.

A significant part of the world's population is directly or indirectly associated with chemical technologies. So, by the end of the 80s of the XX century. in one country alone, the United States, more than 1 million people were employed in the chemical industry and related industries, including over 150,000 scientists and process engineers. In those years, the United States sold about $ 175-180 billion worth of chemical products a year.

Chemical technology and its associated industry are forced to respond to society's desire to preserve the environment. Depending on the political atmosphere, this urge can range from reasonable caution to panic. In any case, the economic consequence is an increase in product prices due to the costs of achieving the desired goal of preserving the environment, ensuring the safety of workers, proving the harmlessness and effectiveness of new products, etc. Of course, all these costs are paid by the consumer and they are significantly reflected on the competitiveness of the products.

Of interest are some figures related to manufactured and consumed products. In the early 70s of the XX century. the average city dweller used 300-500 different chemical products in his daily life, of which about 60 - in the form of textiles, about 200 - in everyday life, at work and during leisure, about 50 medicines and the same amount of food and food preparation. Manufacturing technology of some food products includes up to 200 different chemical processes.

About ten years ago, there were more than 1 million varieties of products manufactured by the chemical industry. By that time, the total number of known chemical compounds was more than 8 million, including about 60 thousand inorganic compounds. More than 18 million chemical compounds are known today. In all laboratories of our planet, 200–250 new chemical compounds are synthesized every day. The synthesis of new substances depends on the perfection of chemical technologies and, to a large extent, on the effectiveness of the management of chemical transformations.

, petrochemical industry, energy, transport, military equipment and many others.

Chemical technologies in historical development

When considering the development of chemical technology in the 20th century, especially after the First World War, it is possible to reveal some of its characteristic, specific features. It is known that 99.5% of the earth's crust consists of 14 chemical elements: oxygen, silicon, carbon, aluminum, iron, calcium, sodium, magnesium, potassium, hydrogen, titanium, phosphorus, chlorine and sulfur. However, despite the massive distribution of many of these elements, they were not pulled into the orbit of the chemical industry in the 19th century. This applies equally to fluorine, titanium, chlorine, magnesium, aluminum and hydrogen.

For chemical technology of the XX century. it is characteristic to refer precisely to these most common elements. Hydrogen is currently the bread of modern chemistry. The synthesis of ammonia, the synthesis of alcohols, the synthesis of liquid fuels, etc., annually require the production of billions of cubic meters of hydrogen. The widespread involvement of hydrogen in chemical production is a characteristic feature of 20th century chemistry.

Of great importance in modern technology is the chemistry of silicon and, in particular, the chemistry of organosilicon compounds. The chemistry of titanium, chlorine, magnesium, potassium, and aluminum is also of exceptional importance. At the same time, chemical technology, especially in connection with the development of atomic and jet technology, tends to use the most rare and scattered elements of the earth's crust, which are the most important basis for 20th century technology.

The basis of organic synthesis of the XIX century. was coal tar obtained by coking coal. In the 20th century, this raw material gives way to simple and readily available gases obtained from a wide range of solid fuels, from peat, low-grade brown coal to anthracite and coke. Gases from oil production and refining are used on a large scale. Throughout the XX century. natural fossil gases are increasingly used (Fig. 1).

Fig. 1. Products derived from natural gas (methane).

Thus, if in the XIX century. the basis of the chemical industry was coal tar, then in the first half of the 20th century. The main raw material base of the organic synthesis industry is coal and oil and the gases obtained from them: hydrogen, carbon monoxide, a rich range of hydrocarbons and whole line other materials. Nitrogen, hydrogen, oxygen, chlorine, fluorine, carbon monoxide, methane, acetylene, ethylene and some other gases are the main raw materials for modern chemistry. Consequently, a characteristic feature of the latest chemical technology is the use of common elements that were previously used on an insignificant scale, and their transformation into the basis of modern chemical technology, as well as the widespread use of solid fuels, liquid and gaseous hydrocarbons as chemical raw materials.

A characteristic feature of chemical technology is also the use of rare elements associated, in particular, with the requirements of nuclear technology. Chemistry contributes significantly to the development of nuclear technology, giving it various materials- metals (uranium, lithium, etc.), heavy water, hydrogen, plastics, etc.

Initially, the production of basic equipment for the synthesis of ammonia was mastered. Synthesis columns, separators, water and ammonia scrubbers for cleaning gases from carbon dioxide and carbon monoxide, as well as centrifuges, vacuum filters, autoclaves for vulcanizing rubber, presses for plastics, deep cooling equipment, etc. have been designed and built. Since the 1920s, they have acquired powerful oil gas separation units, highly efficient rectification and adsorption equipment, high pressure compressors and reactors, refrigeration units, etc. carbon, methane, acetylene, ethylene and some other gases are the main raw materials for modern chemistry.

Consequently, a characteristic feature of the latest chemical technology is the use of common elements that were previously used on an insignificant scale, and their transformation into the basis of modern chemical technology, as well as the widespread use of solid fuels, liquid and gaseous hydrocarbons as chemical raw materials.

A characteristic feature of chemical technology is also the use of rare elements associated, in particular, with the requirements of nuclear technology. Chemistry contributes significantly to the development of nuclear technology, giving it various materials - metals (uranium, lithium, etc.), heavy water, hydrogen, plastics, etc.

It should be noted that one of the features of modern chemistry is the requirement for the purity of the products produced. The impurities contained in the starting materials often negatively affect the properties of the resulting product. Therefore, in recent years, very pure starting materials (monomers), containing at least 99.8-99.9% of the basic substance, have been increasingly used in the chemical industry. A characteristic feature of modern chemical technology is that it is equipped with new methods of influence; especially important are the use of high pressures from several hundred to 1500-2000 and above atmospheres, deep vacuum (up to thousandths of an atmosphere), high temperatures up to several thousand degrees, the use of deep cold (low temperatures close to absolute zero), as well as the use of electric discharges , ultrasound, radioactive radiation, etc. It is natural that the increase in the technical level of chemical production in general, and, consequently, the rapid development of the organic synthesis industry in particular, is ensured by the supply of the chemical industry with modern, high-performance equipment, appropriate apparatuses and machines. Initially, the production of basic equipment for the synthesis of ammonia was mastered. Synthesis columns, separators, water and ammonia scrubbers for cleaning gases from carbon dioxide and carbon monoxide, as well as centrifuges, vacuum filters, autoclaves for vulcanizing rubber, presses for plastics, deep cooling equipment, etc. have been designed and built. starting from the 1920s, they acquired powerful oil gas separation units, highly efficient rectification and adsorption equipment, high-pressure compressors and reactors, refrigeration units, etc. The main trend of modern chemistry is the desire to design the molecular structure of a substance in advance in accordance with predetermined properties. The synthesis of substances with predetermined properties in modern chemistry is not carried out blindly, but on the basis of a deep study of the laws of the formation of molecules. Therefore, a number of new branches of chemical science are undergoing great development.

In essence, from random searches and finds, chemistry, starting in the 1920s, moved on to the systematic replacement and displacement of natural scarce materials with materials that are not only not inferior in quality, but, on the contrary, superior to these natural materials. For example, Chilean natural nitrate has been supplanted by synthetic nitrogen compounds. Synthetic rubber is not inferior in quality to natural rubber. In recent years, some researchers have been working to improve the quality of not synthetic, but natural rubber, so that it can compete with some special types of synthetic rubbers. Great strides have been made in the field of synthetic fiber synthesis, the production of which goes back a few decades.

Since the 1920s, natural products have been pushed aside and replaced by synthetic products of equal quality. This is a completely natural process. The fact is that chemical methods of processing a substance, the introduction of chemical processes into production lead to a significant reduction in production time and to a significant reduction in labor costs, and at the same time to obtaining products of higher quality than organic products... So, if the production of 1 ton of artificial viscose staple fiber requires 70 man-days, then the production of 1 ton of cotton fiber takes 238 man-days. In the production of rayon silk, labor costs are about 10 times less than in the production of natural silk. When 1 ton of ethyl alcohol (necessary for the production of a number of synthetic products) is obtained from petroleum raw materials, labor costs are reduced by 20-22 times in comparison with the production of this alcohol from food raw materials. ... Currently, 100 thousand inorganic chemical compounds are known in nature, while the number of known organic substances, natural and artificial, has exceeded three million and continues to grow rapidly. Only industrially developed compounds obtained on the basis of oil number 10 thousand names. Along with the creation of new synthetic materials, there is a continuous process of improving the quality of existing substances produced by industry. Finally, at present, the fundamental possibility of artificially obtaining natural compounds of any complexity has been proven. The time is not far off when the laboratories of organic chemists will synthesize of various kinds complex protein substances that are the basis of life.

A characteristic feature of modern technology is that it develops on the basis of the widest use of electricity. Moreover, if earlier the steam engine only to some extent provided technological "raw material" for the chemical industry in the form of steam and heat, then electricity becomes essential element a kind of technological "raw material" for such, for example, processes as electrolysis.

For the production of ammonia, synthesized from hydrogen and nitrogen obtained by electrolysis of water, it is necessary to consume about 12 thousand kWh of electricity. For the manufacture of synthetic rubber based on ethylene, about 15 thousand kW-h are consumed, and for some other types of rubber - 17 thousand kW-h and even more. The production of one ton of silk acetate requires 20 thousand kW-h, tons of phosphorus - from 14 to 20 thousand kW-h and a ton of artificial abrasives - about 6-9 thousand kW-h - this is about the same as for production powerful tractor.

The development of the chemical industry is characterized by the broadest automation of technological processes. Comprehensive automation is primarily necessary precisely in the chemical industry, which is characterized by large-scale production. The automation of the chemical industry is facilitated by the predominance of continuous production processes in it, as well as harmful and even dangerous work. In the chemical industry, first of all, the processes of regulating temperature, pressure, composition, reaction rate, etc. are fully automated, since for continuous chemical processes (inaccessible for direct observation) it is especially important to maintain the stability of technological modes. In the chemical production, complete mechanization and automation have been carried out, and only the functions of supervision and control, as well as the implementation of preventive repairs, remain for the person.

The most important directions in the automation of chemical production are the introduction of new automatic devices based on the use of electronic mathematical machines, the transition to complex mechanization and automation of entire chemical plants. In the USA, production automation was most developed precisely in the oil and chemical industries. Along with the automation of the control of individual plants, individual technological processes are fully commissioned automated enterprises such as, for example, the oil refinery, which was put into operation in 1949, equipped with an electronic control system for production processes, and then the ammonia plant of the Spencer Chemical Company, which is distinguished by a high degree of automation of production processes. The rapid development of chemistry led to the fact that only within 10-15 years after the end of the Second World War hundreds of new materials were created, replacing metal, wood, wool, silk, glass and much more.

The production of synthetic materials required to ensure technical progress in various sectors of the national economy is developing at an accelerated pace. At the same time, an increase in the production of mineral fertilizers, as well as pesticides and ammonia, an increase in the use of oil and natural gases, coke oven gas and coal coking products for the production of synthetic resins, rubber, alcohol, detergents, high-quality varnishes and dyes, plastics, artificial fibers are characteristic, electrical insulating materials, special materials for mechanical engineering, radio engineering, etc.

In particular, the introduction of new effective methods of synthesis is carried out in order to avoid the consumption of huge quantitative food products in the production of technical products. For example, the consumption of a huge amount of grain for the production of ethyl alcohol for the production of synthetic rubber has raised the problem of replacing food with synthetic alcohol. To obtain 1 ton of ethyl alcohol instead of 4 tonnes of grain or 10 tonnes of potatoes, it is enough to consume 2 tonnes of liquefied natural gas. To produce 1 ton of synthetic rubber, instead of almost 9 tonnes of grain or 22 tonnes of potatoes, it is enough to spend only about 5 tonnes of liquefied gases from refineries.

Many economists believe that in the next decade, more than 50% of the world's chemical products will be derived from petroleum feedstocks. All this speaks of great achievements in organic synthesis.

After the October Revolution of 1917, the development of socialist production required expanding the sphere of practical application of chemistry, increasing the role of special chemical and chemical-technological education, raising the level of training of researchers and teachers, as well as chemical engineers. In the early 1920s. independent chemical departments are organized within the physics and mathematics departments of universities. These departments have introduced specializations in inorganic, physical, organic, analytical chemistry, biochemistry and agrochemistry. In 1920, the Moscow Institute of Chemical Technology was established. D.I. Mendeleev. Since 1929, on the basis of chemical departments at universities, independent chemistry faculties for the training of specialists for scientific research institutions and laboratories of chemical production, new chemical-technological institutes are being created.

Since the mid-1950s. in chemistry and chemical technology, the finest methods of researching various substances are being created, new materials are being produced - chemical fibers, plastics, sitalls, semiconductors, new physiologically active substances and drugs, chemical fertilizers and insectofungicides. Chemistry has penetrated into all branches of science and the national economy. Therefore, chemical education has become an integral part of the training of specialists in polytechnical, industrial, metallurgical, energy, electrical, mechanical and instrument-making, geological, mining, oil, agricultural, forestry, medical, veterinary, food, light industry, and other higher and secondary specialized educational institutions.

Specialists for scientific and pedagogical activity are trained mainly by the chemical departments of universities and pedagogical institutes, as well as by the departments of chemical-biological, biological-chemical, natural science, etc.

The training of chemists in Soviet universities lasts 5 years (in evening and correspondence departments - up to 6 years). Special courses in inorganic, organic, analytical, physical, colloidal chemistry, crystal chemistry, general chemical technology, chemistry of macromolecular compounds are studied here. More than half of the study time in special disciplines is occupied by the work of students in laboratories. Students pass industrial practice(28 weeks) at enterprises, research institutions and laboratories.

The training of specialists in chemistry and chemical technology and teachers for higher educational institutions continues in graduate school. The largest centers for the training of chemists, besides universities, are the following institutes: DI Mendeleev, Leningrad Technological named after Lensovet, Moscow Institute of Fine Chemical Technology. MV Lomonosov, Belarusian Technological named after S. M. Kirov, Voronezh Technological, Dnepropetrovsk Chemical Technological named after F.E.Dzerzhinsky, Ivanovo chemical-technological, Kazan chemical-technological named after. S. M. Kirov, Kazakh chemical-technological, etc.

Specialists-chemists (technicians-technologists) are also trained in secondary specialized educational institutions - in chemical and chemical-technological technical schools, located, as a rule, in the centers of the chemical industry, at large chemical plants. In 1977, over 120 such educational institutions trained technicians in over 30 chemical and chemical-technological specialties (chemical technology of oil, gas, coal, glass and glass products, technology of chemical fibers, etc.). Those who graduated from these educational institutions are employed in chemical industries as foremen, foremen, laboratory assistants, apparatus operators, etc. Chemical-technological vocational schools satisfy the need for skilled workers for various branches of the chemical industry.

Improving the structure and content of chemical and chemical engineering education is associated with scientific and teaching activities many Soviet scientists - A. E. Arbuzov, B. A. Arbuzov, A. N. Bach, S. I. Volfkovich, N. D. Zelinsky, I. A. Kablukov, V. A. Kargin, I. L. Knunyants, D.P. Konovalov, S.V. Lebedev, S.S. Nametkina, B.V. Nekrasov, A.N. Nesmeyanov, A.E. Reformatsky, N.N.Semenov, Ya.K. Syrkin, V.E. Tishchenko, A.E. Favorsky and others. school.

In developed countries, major centers of the structure and content of chemical and chemical-technological education are: Great Britain - Cambridge, Oxford, Bath, Birmingham universities, Manchester Polytechnic Institute; in Italy - Bologna, Milan universities; in the USA - California, Columbia, Michigan Technological Universities, Toledo University, California, Massachusetts Institute of Technology; in France - 1st Grenoble, 1st Marseilles, Clermont-Ferrand, Compiegne technological, Lyons 1st, Montpellier 2nd, Paris 6th and 7th universities, Laurent, Toulouse polytechnic institutes; in Hepmania - Dortmund, Hanover, Stuttgart universities, higher technical schools in Darmstadt and Karlsruhe; in Japan - Kyoto, Okayam, Osaka, Tokyo universities, etc.

, M., 1971;

Fundamentals of Technology and Petrochemical Synthesis, ed. A.I.Dinces and L.A. Potolovsky, M., 1960.

Modern chemical technologies and artificial materials. Chemical technology. Fundamentals of chemical technology in domestic education

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