1, application of nanotechnology in new materials
2. The application of nanotechnology in microelectronics and electric power.
3. Application of nanotechnology in manufacturing industry
4. Application of nanotechnology in biology and medicine.
5. Application of nanotechnology in chemical and environmental monitoring.
6. Application of nanotechnology in energy, transportation and other fields.
7. Application of nanotechnology in agriculture
8. Application of nanotechnology in daily life
Adding nanoparticles to textiles and chemical fiber products can deodorize and sterilize. Although chemical fiber cloth is strong, it has annoying static phenomenon, which can be eliminated by adding a small amount of metal nanoparticles.
Using nano-materials, refrigerators can resist bacteria. Sterile tableware and aseptic food packaging products made of nano-materials have come out. By using nano-powder, wastewater can be completely turned into clean water, which fully meets the drinking standards. Nano food is delicious and healthy.
The application of nanotechnology can improve the washability of wall coatings by 10 times. Self-cleaning glass and self-cleaning tiles can be made by coating nano-thin layers on the surfaces of glass and tiles without scrubbing at all. Building materials containing nanoparticles can also absorb ultraviolet rays harmful to human body.
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Nanomaterials can improve the performance of vehicles. Nano-ceramics are expected to become ideal materials for engine parts such as automobiles, ships and airplanes, which can greatly improve the efficiency, working life and reliability of engines. Nanosatellites can provide drivers with traffic information at any time to help them drive safely.
The micro drug delivery device made of nanotechnology can carry a certain dose of drugs and reach the focus accurately under the guidance of electromagnetic signals in vitro, which can effectively play a therapeutic role and reduce the adverse reactions of drugs. Micro robots made of nano-materials are smaller than red blood cells. By injecting them into patients' blood vessels, cerebral vascular thrombosis can be dredged. Remove fat and deposits from heart arteries, and also "chew" stones in the urinary system. Nanotechnology will be a good helper for a healthy life.
The application prospect of nanotechnology is very broad, and the economic benefit is very huge. American authorities predict that the nanotechnology market will reach144 billion dollars in 20 10, and the application of nanotechnology will far exceed the computer industry in the future. Nano-composite, modification of plastics, rubber and fiber, design and application of nano-functional coating materials will inject new high-tech content into traditional production and products. Experts pointed out that in the fields of textiles, building materials, chemicals, petroleum, automobiles, military equipment and communication equipment, a "material revolution" triggered by nanotechnology is bound to occur. At present, nearly 65,438+000 companies in China have registered nanomaterials and nanotechnology, and more than 65,438+00 production lines for nanomaterials and nanotechnology have been established. Nano-fabrics and clothing have been mass-produced, such as computer work clothes, anti-static clothes, anti-ultraviolet clothes and so on. The new coating with nanotechnology not only improves the washability by more than ten times, but also is nontoxic, harmless and odorless. Nanotechnology is improving and improving people's quality of life.
Nanotechnology-Basic Concepts
nanotechnology
Nanoscience and technology, sometimes called nanotechnology, studies the properties and applications of materials with structural dimensions ranging from 0. 1 to 100 nm.
After the invention of 198 1 year scanning tunneling microscope, a molecular world with a length of 0. 1 to 100 nm was born, and its ultimate goal is to construct products with specific functions directly from atoms or molecules. Therefore, nanotechnology is actually a technology that uses single atoms and molecules to arrange substances.
Nanotechnology is a comprehensive subject with strong cross-cutting, and its research content involves the vast field of modern science and technology. Nano-science and technology mainly includes nano-system physics, nano-chemistry, nano-materials, nano-biology, nano-electronics, nano-processing, nano-mechanics and so on. The preparation and research of nano-materials are the basis of the whole nano-technology. Among them, nano-physics and nano-chemistry are the theoretical basis of nano-technology, and nano-electronics is the most important content of nano-technology.
From the current research, there are three concepts about nanotechnology:
The first is 1986, the molecular nanotechnology put forward by American scientist Dr. drexler in his book The Machine of Creation. According to this concept, we can make the machine of combining molecules practical, so that we can combine various molecules at will and make any molecular structure. The nanotechnology of this concept has not made significant progress.
The second concept defines nanotechnology as the limit of micromachining technology. That is, the technology of artificially forming nano-scale structures through nano-precision "processing". This nano-scale processing technology also makes the miniaturization of semiconductors reach the limit. Even if the existing technology continues to develop, it will eventually reach the limit in theory, because if the line width of the circuit is gradually reduced, the insulation film forming the circuit will become extremely thin, destroying the insulation effect. In addition, there are problems such as fever and trembling. In order to solve these problems, researchers are studying new nanotechnology.
The third concept is put forward from a biological point of view. It turns out that organisms have nano-scale structures in cells and biomembranes. The development of DNA molecular computer and cell biological computer has become an important part of nanotechnology.
Nanotechnology-Development History
The inspiration of nanotechnology comes from a speech by the late physicist richard feynman 1959 entitled "There is still a lot of room at the bottom". The professor who teaches at California Institute of Technology put forward a new idea to his colleagues. Since the Stone Age, all human technologies, from sharpening arrows to photoetching chips, have been related to cutting or fusing hundreds of millions of atoms at one time in order to make substances into useful forms. Feynman believes that the laws of physics do not rule out the possibility of making objects atom by atom.
Richard feynman, a famous physicist and Nobel Prize winner, predicted that human beings can make smaller machines with small machines, and eventually they will arrange atoms one by one according to human wishes to make products. This is the earliest dream about nanotechnology.
In 1970s, scientists began to put forward ideas about nanotechnology from different angles. 1974, scientist Donnie Gucci first used the term nanotechnology to describe precision machining.
1982, scientists invented the scanning tunneling microscope, an important tool for studying nanotechnology, which revealed a visible atomic and molecular world for us and played a positive role in promoting the development of nanotechnology.
1990 in July, the first international nanotechnology conference was held in Baltimore, USA, marking the official birth of nanotechnology.
1990, scientists from IBM almaden Research Center successfully rearranged individual atoms, and a key breakthrough was made in nanotechnology. They used a device called scanning probe to slowly move 35 atoms to their respective positions, forming three letters of IBM. This proves that Feynman is right. Using molecular beam epitaxy, scientists have learned how to make extremely thin special crystal films, and only one layer of molecules can be made at a time.
199 1 year, carbon nanotubes were discovered by humans. Their mass is one sixth of that of steel with the same volume, but their strength is 10 times that of steel, which has become the focus of nanotechnology research. Professor smalley, winner of the Nobel Prize in Chemistry, believes that carbon nanotubes will be the first choice for the best fibers in the future, and will also be widely used in ultramicro wires, ultramicro switches and nanoelectronic circuits.
1993, following 1989, when Stanford University moved the atomic group to "write" Stanford University's English, and 1990, when IBM expelled "IBM" from the nickel surface with 36 xenon atoms, the Beijing Vacuum Physics Laboratory of Chinese Academy of Sciences manipulated the atoms freely and successfully wrote the word "China", which marked the beginning of China's international nanotechnology field.
1997, American scientists successfully used single electrons to move single electrons for the first time. It is expected that quantum computers with thousands of times higher speed and storage capacity will be developed in 20 years.
1999, Brazilian and American scientists invented the world's smallest "scale" when conducting experiments on carbon nanotubes, and its weight can reach one billionth of a gram of an object, equivalent to the weight of a virus; Shortly thereafter, German scientists developed a scale that can weigh a single atom, breaking the record jointly created by American and Brazilian scientists.
By 1999, nanotechnology has gradually entered the market, and the annual turnover based on nano-products has reached 50 billion US dollars.
Since 2000, some countries have formulated relevant strategies or plans and invested huge sums of money to seize the strategic highland of nanotechnology. Japan has set up a research center for nanomaterials, which has incorporated nanotechnology into the research and development focus of the new five-year science and technology basic plan; Germany has established a nanotechnology research network; The United States regards the nano plan as the core of the next industrial revolution. The investment of American government departments in basic research of nanotechnology increased from $65,438+1160,000 in 1997 to $497 million in 2006.
Nanotechnology-a branch of technology
From 65438 to 0993, the first International Conference on Nanotechnology (INTC) was held in the United States. The conference divided nanotechnology into six branches: nano-physics, nano-biology, nano-chemistry, nano-electronics, nano-processing technology and nano-metrology.
Nanodynamics
Nano-dynamics, mainly micro-machinery and micro-motor, or micro-electromechanical system (MEMS), is applied to micro-sensors and actuators of belt-driven machinery, optical fiber communication systems, special electronic equipment, medical and diagnostic instruments, etc. It adopts a new technology similar to the design and manufacture of integrated appliances. The feature is that the parts are very small, the etching depth often needs tens to hundreds of microns, and the width error is very small. This process can also be used to manufacture three-phase motors, ultra-high-speed centrifuges or gyroscopes. In the research, micro-deformation and micro-friction at quasi-atomic scale should be detected accordingly. Although they have not really entered the nanometer scale at present, they have great potential scientific and economic value.
Theoretically, micro-motor and detection technology can reach nanometer level.
Nanobiology and Nanopharmacology
Nano-biology and nano-pharmacology, such as fixing DNA particles on mica surface with nano-particle colloidal gold, doing experiments on the interaction between biomolecules on the interdigital electrode on the surface of silica, detecting the double-layer planar biofilm of phospholipids and fatty acids, and the fine structure of DNA. With nanotechnology, you can also put parts or components into cells through self-assembly to form new materials. About half of the new drugs, even the fine powder of micron particles, are insoluble in water; However, if the particles are nanoscale (i.e. ultrafine particles), they can be dissolved in water.
When nano-organisms develop to a certain technology, nano-biological cells with recognition ability can be made of nano-materials, and the biomedical absorption of cancer cells can be injected into the human body for targeted killing of cancer cells.
Nanoelectronics
Nanoelectronics includes nano-electronic devices based on quantum effect, optical/electrical properties of nanostructures, characterization of nano-electronic materials, and atomic manipulation and assembly. The current trend of electronic technology requires smaller, faster and colder equipment and systems. Smaller means faster response. Being colder means that a single device consumes less power. But smaller is not infinite. Nanotechnology is the last frontier of builders, and its influence will be enormous.
Nanotechnology —— Research and Application of Atomic Force Microscope —— Nanomeasurement Technology
It mainly includes: nano-scale measurement technology; Nano-scale surface physical and mechanical properties testing technology; Nano-machining technology; Preparation technology of nanoparticles; Nanomaterials; Nanobiotechnology; Nanoassembly technology, etc.
1, nanometer is the unit of measurement for geometric dimensions, 1 nanometer = one millionth of a millimeter.
2. Nanotechnology has promoted the technological revolution.
3. Drugs made by nanotechnology can block capillaries and "starve" cancer cells.
4. If nano-integrated devices are used on the satellite, the satellite will be smaller and easier to launch.
Nanotechnology is a synthesis of many sciences, and some goals take a long time to achieve.
6. Nanotechnology, information science and technology and life science and technology are the mainstream of current scientific development, and their development will make human society, living environment and science and technology itself better.
sewage disposal
Compared with traditional water treatment methods, nano-water treatment occupies less land and consumes less manpower and energy, which makes it possible to become an important way to help developing countries and even the world alleviate the upcoming water crisis. [1] In April, 2065438+02, nanotechnology experts from the University of Manchester in England said that they would extract biofuel from toilet wastewater through new nanomaterials and purify it into drinking water. This new invention, sponsored by the Bill and Melinda Gates Foundation, is expected to solve the water shortage problem of millions of people in developing countries [2].
measuring technique
Nano-scale measurement technology includes: precise measurement of nano-scale size and displacement, nano-scale surface morphology measurement. There are two main development directions of nano-scale measurement technology.
One is optical interferometry, which uses interference fringes of light to improve the resolution of measurement. Its measurement methods include: dual-frequency laser interferometry, optical heterodyne interferometry, X-ray interferometry, F-P standard tool measurement and so on. It can be used for accurate measurement of length and displacement, and also for measurement of surface micro-morphology.
The second is scanning probe microscopy (STM), whose basic principle is tunneling effect based on quantum mechanics. Its principle is to scan the measured surface with a very sharp probe (or similar method) (the probe is not actually in contact with the measured surface), and measure the three-dimensional micro-stereoscopic morphology of the surface with the help of a nano-scale three-dimensional displacement positioning control system. It is mainly used to measure the micro-morphology and size of the surface.
The measurement methods using this principle include scanning tunneling microscope (STM) and atomic microscope (AFM).
Detection of physical and mechanical properties of decayed layer
The physical, chemical, mechanical properties and internal properties of extremely thin surface layers of various materials are often very different. It is this extremely thin surface material that plays a leading role in friction and wear, physical, chemical and mechanical behavior. The emergence of new "intelligent" materials, such as computer disks and optical disks, reflected in the current "information age" requires small surface layer, excellent electrical, magnetic and optical properties, good lubricity, low friction, wear resistance, chemical corrosion resistance, stable structure and excellent mechanical properties. Therefore, countries all over the world attach great importance to the study of physical, chemical and mechanical properties of nano-scale surface layers of materials and their detection methods. The detection method of physical and mechanical properties of nano-scale surface layer is mainly surface micromachining probe side detection, and its mechanical properties are detected by nano-indentation principle. Its basic principle is to use the diamond tip to press the nano-scale or micro-scale indentation on the sample surface with minimal force, and measure the mechanical properties of the sample surface according to the indentation size, that is, to continuously record the change of indentation depth in the whole process of gradually pressing and unloading the probe tip and gradually withdrawing from the sample surface. Because it contains a variety of information such as elastic deformation, plastic deformation and deformation rate, many mechanical properties of surface materials can be measured by these information.
Material technology
I. Nanocrystalline materials (nanocrystalline materials)
When the microstructure of matter is miniaturized, the number ratio of surface atoms to internal atoms increases significantly, and the atomic behavior at the interface has a decisive influence on the properties of matter. For example, nanocrystalline metal particles show better strength, hardness, magnetism, surface catalysis and so on. Compared with ordinary ceramic materials, nanocrystalline ceramic materials have higher ductility and are not prone to brittle fracture.
Second, nano powder (nanoparticles)
Nano-powder is one of the most diverse and widely used nano-materials. The most common ceramic nanoparticles can be further divided into two categories: metal oxides, such as TiO2 _ 2 and ZnO silicates, usually nano-scale clay flakes. Their applications include:
(1) composites: One of the biggest applications of nano-powder is to develop nano-polymer composites. Due to the interaction between the surface area of inorganic dispersed phase and polymer, the rigidity of the composite material is greatly improved, and the permeability and thermal expansion are reduced. It has the advantages of chemical corrosion resistance and transparency, and can be widely used in general livelihood industries, such as household appliances, automobile parts, transportation pipelines and other wear-resistant structural materials. In the application of packaging materials, such as plastic wrap and beverage bottles, we can make use of its heat resistance, high gas resistance and transparency. Caly/ nylon composites are well dispersed. Adding 3% ~ 4% can increase the melting point of nylon from 70℃ to 150℃, and the processability is very good.
(2) Coating: Nano-powder coating has the characteristics of enhancing surface hardness, wear resistance and transparency, and has been applied to building materials and sunglasses lenses. Kodak is developing scratch-resistant X-ray film with nano-powder coating. In addition, nano-powder coatings have applications in optics, corrosion resistance and heat insulation. Magnetic nano-powder coating can be applied to data storage.
(3) Medicine and drugs: surface modified nano-powder can be used for drug delivery, nano-silver particles have antibacterial effect, and zinc oxide has bactericidal effect. TiO2 _ 2 and ZnO have a good effect on ultraviolet absorption and can be used in beauty products such as sunscreen oil.
(4) Others: the high surface area of nano-powder can use industrial catalytic reaction; When used in fuel cells, the reaction rate can be increased and the efficiency can be improved. In addition, the development of nano-pigments, the use of metal nano-powder printed electronic circuits, and the application of magnetic nano-powder in semiconductor and medical magnetic resonance imaging are all applications of nano-powder.
Three, nano porous materials (nano porous materials)
This kind of material refers to porous materials with pore size less than 100 nm, including biofilm and zeolite that have existed in nature for a long time. Their high surface area (usually as high as about 102 m2 /g) makes them have high catalytic and adsorption effects. Nano-porous materials can be prepared by sol-gel method, photolithography and etching, ion beam and other methods. Nanoporous films can be coated to obtain nanotube structures.
Nano-porous materials can be used to develop and improve catalysts and applied to petrochemical industry. Using pore structure, nano-porous materials have great application potential in membrane filtration system purification/separation, drug delivery implantation device, gene sequencing, medical detection and so on. Aerogel is a light and good thermal insulation material. Nanoporous films can be used as low dielectric materials in semiconductor industry. Nano-porous silicon has special luminescent properties and can be used as a material for solid-state lasers. Nano-porous carbon has high capacitance, which can be applied to the development of batteries such as notebook computers, mobile phones and even electric vehicles.
4. Nanofibers and nanowires (nanowires)
Nanofibers here refer to relatively short fibers, including carbon fibers, artificial polymer fibers, alumina fibers and so on. Electrospinning is a method of manufacturing artificial polymer nanofibers, which can combine materials such as nanoparticles or nanotubes into fibers. The electrospun nanofibers being developed by the Institute of Chemical Engineering of the Industrial Research Institute are about1100.
Nanocables tend to be inorganic materials, including metals, semiconductors (such as silicon and germanium) and some organic polymers, which are mainly used in electronic engineering. There are three main methods:
(1) lithographic etching or rubbing.
(2) chemical growth.
(3) Self-assembly and growth.
The electron transfer behavior of nano-cable does not follow classical electricity, for example, its resistance is a certain value, which does not change with the length; When applied to the construction of complex circuit systems, the difficulty to be challenged lies in the connectivity between cables.
Nanofibers can be used in composite materials and surface coatings to achieve reinforcement. Hyperion Catalysis International is developing and using carbon nanofibers to make conductive plastics and films, which can be applied to electrostatic coating of automobiles or electrostatic elimination of electrical equipment. Compared with traditional conductive plastic materials, the amount of carbon fiber needed to achieve the same conductive effect is lower and the surface of the material is smoother.
Electrospun nanofibers have the characteristics of high strength and high surface area, and are suitable as reaction beds for nano-powders in catalytic applications. Nanofibers can be made into fabrics with special properties such as chemical resistance, water resistance, air permeability and antifouling, and have a broad market in the textile and garment industry. Nano-Tex has developed commercial products. Nanofibers can be used as filter materials and scaffold materials for medical tissue engineering. It also has application potential in drug delivery media, sensors, nano-motors and other fields.
Verb (abbreviation for verb) carbon nanotubes
Carbon nanotubes (CNT) were discovered in 199 1 year by Sumio Iijima, a Japanese NEC company. When carbon cluster is observed by transmission electron microscope, it is a tubular material formed by planar curling of graphite, which has two structures: single wall and multi-wall. The manufacturing methods of carbon nanotubes include arc discharge, laser evaporation/stripping, chemical vapor deposition, vapor growth, electrolysis and flame generation. Carbon nanotubes (CNTs) have many special properties, such as high tensile strength (100Gpa), excellent thermal conductivity and room-temperature superconductivity. Their electrical conductivity varies with different crimping methods, and they can be nanowires or semiconductors. Studies show that carbon nanotubes can adsorb hydrogen, but its mechanism and adsorption efficiency are still inconclusive.
Nanobiology
Flagella motor
Nanobiology is to study the structure and function of various organelles in cells on the nanometer scale. Study the exchange of matter, energy and information within cells and between cells and the whole organism. The research of nanobiology mainly focuses on the following aspects.
First, the study of genetic material DNA.
This research has made a lot of progress in morphological observation, characteristic research and genetic modification.
Second, the study of brain function.
The goal of the work is to find out the advanced neurological functions of human memory, thinking, language and learning and the information processing functions of human brain.
Third, the study of bionics.
This is a hot research content of nanobiology. This is a promising part of nanotechnology. The smallest motor in the world is a kind of biological motor-flagella motor. It can rotate like a propeller to drive the flagella to rotate. Motor is usually composed of 10 protein population, and its structure is like an artificial motor. It consists of stator, rotor, bearing and universal joint. Its diameter is only 30nm, the rotating speed can be as high as 15r/min, and it can switch between right turn and left turn within 1 μ s ... It can accelerate or decelerate by using external electric field. The power source of rotation is the concentration difference of nitrogen and oxygen ions inside and outside the membrane supporting the motor in bacteria. Experiments prove that. The potential difference inside and outside the bacteria can also drive the flagella motor. Now people are exploring to design an artificial flagella motor driver which can be controlled by potential difference.
Nanotechnology-potential danger
The potential hazards of nanotechnology can be roughly divided into the following aspects:
health problem
There are four ways for nanoparticles to enter the human body: inhalation, swallowing, skin absorption or intentional injection (or release from implants) during medical treatment. Once in the human body, they are highly mobile. In some cases, they can even cross the blood-brain barrier.
The behavior of nanoparticles in organs is still a big topic to be studied. Basically, the behavior of nanoparticles depends on their size, shape and interaction with surrounding tissues. They may lead to "overload" of phagocytes (cells that devour and destroy foreign substances), thus causing defensive fever and reducing the body's immunity. They may accumulate in organs because they cannot degrade or degrade slowly. Another worry is their potential danger of reacting with some biological processes in the human body. Due to the huge surface area, nanoparticles exposed to tissues and liquids will immediately adsorb the macromolecules they encounter. For example, this will affect the regulation mechanism of enzymes and other protein.
environmental problems
The main concern is the possible harm caused by nanoparticles.
social risk
The use of nanotechnology also has social risks. At the instrument level, it also includes the possibility of applying nanotechnology in the military field.