Abstract: Properties of nanoparticles

Ministry of Science and Education of the Russian Federation

State educational institution

higher professional education

Moscow State Open University (MSOU)

Department of Chemical Technology of Polymer Materials Processing

and organic matter

Coursework in the discipline

"Nanotechnology"

Properties of nanoparticles

Performed by student Efimova L.A.

Faculty of Chemical Technology

Course 4

Specialty 240502 “Technology for processing plastics

and elastomers"

Code 405269

Checked by Doctor of Technical Sciences, Professor

honored worker high school RF Sheverdyaev O.N.

Moscow 2009

Introduction

1. History

2. Definition

3. Classification of nanoobjects

4. Properties of nanoparticles

4.1 Silver

4.2 Zinc oxide

4.3 Silicon dioxide

5. Some advances based on nanoparticles

5.1 Nanomaterials

5.2 Nanocrystals

5.3 Nanomedicine and chemical industry

5.4 Computers and microelectronics

5.5 Robotics

Literature

Introduction

The field of nanotechnology is considered worldwide to be a key topic for 21st century technology. The possibility of their versatile application in such areas of the economy as semiconductor production, medicine, sensor technology, ecology, automotive, building materials, biotechnology, chemistry, aviation and astronautics, mechanical engineering and the textile industry, carry enormous growth potential. The use of nanotechnology products will save on raw materials and energy consumption, reduce emissions into the atmosphere and thereby contribute to sustainable development economy.

On the one hand, nanotechnology has already found areas of application, on the other hand, it remains the realm of science fiction for the majority of the population. The importance of nanotechnology will only grow in the future. IN specialized area this will awaken interest and stimulate research and development work, as well as work to find new areas of application of nanotechnology.

This course work examines some properties of nanoparticles of various chemical elements and their connections. Some advances based on nanoparticles are presented.

1. History

Many sources, primarily English-language ones, associate the first mention of methods that would later be called nanotechnology with famous performance Richard Feynman “There's a lot of room down there.”(English) « There’ s Plenty of Room at the Bottom» ), made by him in 1959 in California Institute of Technology at the annual meeting of the American Physical Society. Richard Feynman suggested that it was possible to mechanically move single atoms using a manipulator of the appropriate size, at least such a process would not contradict the laws of physics known today.

He suggested doing this manipulator in the following way. It is necessary to build a mechanism that would create a copy of itself, only an order of magnitude smaller. The created smaller mechanism must again create a copy of itself, again an order of magnitude smaller, and so on until the dimensions of the mechanism are commensurate with the dimensions of the order of one atom. In this case, it will be necessary to make changes in the structure of this mechanism, since the gravitational forces acting in the macrocosm will have less and less influence, and the forces of intermolecular interactions and van der Waals forces will increasingly influence the operation of the mechanism. The last stage - the resulting mechanism will assemble its copy from individual atoms. In principle, the number of such copies is unlimited; it will be possible to create an arbitrary number of such machines in a short time. These machines will be able to assemble macro-things in the same way, by atomic assembly. This will make things much cheaper - such robots (nanorobots) will need to be given only the required number of molecules and energy, and write a program to assemble the necessary items. So far, no one has been able to refute this possibility, but no one has yet managed to create such mechanisms. The fundamental disadvantage of such a robot is the impossibility of creating a mechanism from one atom.

During theoretical research Given this possibility, hypothetical doomsday scenarios have emerged, which suggest that nanorobots will absorb all the biomass of the Earth, carrying out their self-reproduction program (the so-called “gray goo” or “gray goo”).

The first assumptions about the possibility of studying objects at the atomic level can be found in the book “Opticks” by Isaac Newton, published in 1704. In the book, Newton expresses his hope that future microscopes will one day be able to explore the “secrets of corpuscles.”

The term “nanotechnology” was first used by Norio Taniguchi in 1974. He used this term to describe the production of products several nanometers in size. In the 1980s, Eric K. Drexler used the term in his books: "Machines of Creation: The Age of Nanotechnology Is Coming" ("Engines of Creation: The Coming Era of Nanotechnology") And "Nanosystems: Molecular Machinery, Manufacturing, and Computation". Central location His research involved mathematical calculations, with the help of which it was possible to analyze the operation of a device several nanometers in size.

2. Definition

The modern trend towards miniaturization has shown that a substance can have completely new properties if you take a very small particle of this substance. Particles ranging in size from 1 to 100 nanometers are usually called nanoparticles .

3. Classification of nanoobjects

Nanoobjects are divided into 3 main classes:

Three-dimensional particles obtained by explosion of conductors, plasma synthesis, reduction thin films etc;

Two-dimensional objects - films produced by molecular deposition, CVD, ALD, ion deposition, etc.;

One-dimensional objects are whiskers; these objects are obtained by the method of molecular layering, introducing substances into cylindrical micropores, etc.

There are also nanocomposites - materials obtained by introducing nanoparticles into any matrices. At the moment, only the microlithography method has been widely used, making it possible to obtain flat island objects with a size of 50 nm on the surface of matrices; it is used in electronics; The CVD and ALD method is mainly used to create micron films. Other methods are mainly used in scientific purposes. Particularly noteworthy are the ionic and molecular layering methods, since with their help it is possible to create real monolayers.

4. Properties of nanoparticles

The most dramatic changes in the properties of nanomaterials and nanoparticles occur in the range of crystallite sizes of the order of 10..100 nm. Basic physical reasons this can be illustrated in Figure 1.

For nanoparticles, the fraction of atoms located in a thin surface layer (~ 1 nm) increases noticeably compared to microparticles.

For example, it turns out that nanoparticles of some materials have very good catalytic And adsorption properties. Other materials show amazing optical properties, for example, ultra-thin films of organic materials are used to produce solar cells. Such batteries, although they have a relatively low quantum efficiency, are cheaper and can be mechanically flexible. Manages to achieve interaction artificial nanoparticles With natural objects nano-sized - proteins, nucleic acids, etc. Carefully purified, nanoparticles can self-align into certain structures. This structure contains strictly ordered nanoparticles and also often exhibits unusual properties.

Rice. 1. The main physical reasons for the specificity of nanoparticles (nanomaterials).

4.1 Silver

The properties of silver nanoparticles are truly unique. Firstly, they have phenomenal bactericidal And antiviral activity . Humanity has known about the antimicrobial properties inherent in silver ions for a very long time. Surely, many have heard about the healing abilities of church “holy water”, obtained by passing ordinary water through a silver filter. Such water does not contain many pathogenic bacteria that may be present in ordinary water. Therefore, it can be stored for years without spoiling or “blooming.” IN medical practice Sometimes “silver” water is prescribed to treat wounds, ulcers, and bladder diseases. In addition, such water contains a certain concentration of silver ions that can neutralize harmful bacteria and microorganisms, which explains its beneficial effect on human health. It has been established that silver nanoparticles are thousands of times more effective in fighting bacteria and viruses than silver ions. As the experiment showed, insignificant concentrations of silver nanoparticles destroyed all known microorganisms (including the AIDS virus) without being consumed (Fig. 2).

Rice. 2. Viruses attack the cell.

In addition, unlike antibiotics, which kill not only harmful viruses, but also the cells affected by them, the action of nanoparticles is very selective: they act only on viruses, without damaging the cell! Currently, research is being conducted into the possibilities of using silver nanoparticles in pharmaceuticals. But now they are finding quite wide application.

For example, toothpastes with silver nanoparticles are currently being produced, which not only clean teeth, but also effectively protect against various infections. Also, small concentrations of silver nanoparticles are added to some creams from the “elite” cosmetics series to prevent them from deteriorating during use. Additives based on silver nanoparticles are used as an anti-allergenic preservative in creams, shampoos, makeup products, etc. When used, an anti-inflammatory and healing effect is also observed.

Textile fabrics containing silver nanoparticles have self-disinfecting properties. Such fabrics are indispensable for medical gowns, bed linen, etc.

Nanoparticles are able to retain bactericidal properties for a long time after application to many hard surfaces (glass, wood, paper, ceramics, metal oxides, etc.). This makes it possible to create highly effective, long-lasting disinfectant aerosols for household use. Unlike bleach, carbolic acid and other chemical disinfectants, aerosols based on nanoparticles are not toxic and do not harm the health of people and animals.

If you add silver nanoparticles to paint materials covering the walls of buildings, then most pathogenic microorganisms cannot live on walls and ceilings painted with such paints. The addition of silver nanoparticles to carbon water filters significantly increases the service life of such filters, and the quality of water purification increases by an order of magnitude.

In addition to disinfecting properties, silver nanoparticles also have high electrical conductivity , allowing the creation of various conductive adhesives. Conductive glue can be used, for example, in microelectronics to connect tiny electronic parts.

Thus, tiny, invisible, environmentally friendly silver nanoparticles can be used wherever it is necessary to ensure cleanliness and hygiene: from cosmetics to the decontamination of surgical instruments or premises.

4.2 Zinc oxide

Zinc oxide nanoparticles also have a number of unique properties(including bactericidal ), among which the ability is of particular interest absorb a wide spectrum of electromagnetic radiation , including ultraviolet, infrared, microwave and radio frequency.

Such particles can serve, for example, to protect against UV rays, giving new functions to glasses, plastics, paints, synthetic fibers, etc. These particles can also be used to prepare sunscreens, ointments and other preparations, as they are safe for humans and do not irritate the skin (Fig. 3).

The ability of zinc oxide nanoparticles to scatter electromagnetic waves can be used in clothing fabrics to give them invisibility properties in the infrared range due to the absorption of emitted human body heat. This makes it possible to produce camouflages that are invisible in a wide range of frequencies - from radio to ultraviolet. Such clothing is simply irreplaceable in military or anti-terrorist operations, as it allows you to get close to the enemy without the risk of being noticed by night vision devices.

Rice. 3. High purity zinc oxide nanoparticles intended for use in electronics, catalysts, medical products, personal care products.

4.3 Silicon dioxide

Nanoparticles of silicon dioxide (SiO 2) have an amazing property: if they are applied to any material, they attach to its molecules and allow the surface to reject dirt and water . Self-cleaning nanocoatings based on these particles protect glass, tiles, wood, stone, etc. Dirt particles cannot stick or penetrate into the protected surface, and water easily drains from it, carrying away any contaminants (Fig. 4).

Rice. 4. Operating principle of self-cleaning nanocoatings.

The fabric, after coating, allows air to pass through freely, but does not allow moisture to pass through. You can forget about stubborn stains from coffee, grease, dirt, etc. The coating is resistant to friction, flexible, and does not deteriorate from sunlight, temperature and washing.

5. Some advances based on nanoparticles

5.1 Nanomaterials

Materials developed on the basis of nanoparticles with unique characteristics arising from microscopic size their components.

Carbon nanotubes - extended cylindrical structures with a diameter from one to several tens of nanometers and a length of up to several centimeters, consisting of one or several hexagonal graphite planes (graphenes) rolled into a tube and usually ending in a hemispherical head.

Fullerenes - molecular compounds belonging to the class of allotropic forms of carbon (others are diamond, carbine and graphite) and are convex closed polyhedra composed of even number tricoordinated carbon atoms.

Graphene - monolayer of carbon atoms obtained in October 2004 at the University of Manchester ( The University Of Manchester). Graphene can be used as a molecular detector (NO 2), allowing the arrival and departure of single molecules to be detected. Graphene has high mobility at room temperature, due to which, as soon as the problem of the formation of a band gap in this semimetal is solved, graphene is being discussed as a promising material that will replace silicon in integrated circuits.

5.2 Nanocrystals

Nanobatteries - at the beginning of 2005, Altair Nanotechnologies (USA) announced the creation of an innovative nanotechnological material for electrodes of lithium-ion batteries. Batteries with Li 4 Ti 5 O 12 electrodes have a charging time of 10-15 minutes. In February 2006, the company began producing batteries at its Indiana plant. In March 2006, Altairnano and Boshart Engineering entered into an agreement to jointly develop an electric vehicle. In May 2006, tests of automobile nanobatteries were successfully completed. In July 2006, Altair Nanotechnologies received its first order to supply lithium-ion batteries for electric vehicles.

5.3 Nanomedicine and chemical industry

Direction to modern medicine based on the use of the unique properties of nanomaterials and nanoobjects for tracking, design and modification biological systems human at the nanomolecular level.

DNA nanotechnology - use specific bases of DNA molecules and nucleic acids to create clearly defined structures based on them.

Industrial synthesis of drug molecules and pharmacological preparations of a well-defined form (bis-peptides).

5.4 Computers and microelectronics

Central processing units - On October 15, 2007, Intel announced the development of a new processor prototype containing the smallest structural element measuring approximately 45 nm. In the future, the company intends to reach the size structural elements up to 5 nm. Intel's main competitor, AMD, has also long been using nanotechnological processes developed jointly with IBM to produce its processors. A characteristic difference from Intel's developments is the use of an additional insulating SOI layer, which prevents current leakage due to additional insulation of the structures that form the transistor. There are already working samples of processors with 45 nm transistors and prototypes with 32 nm.

Hard disks - in 2007, Peter Grunberg and Albert Furth received the Nobel Prize in Physics for the discovery of the GMR effect, which allows data to be recorded on hard drives with atomic information density.

Atomic force microscope - scanning probe microscope high resolution, based on the interaction of the cantilever needle (probe) with the surface of the sample under study. Typically, interaction refers to the attraction or repulsion of a cantilever from a surface due to van der Waals forces. But when using special cantilevers, it is possible to study electrical and magnetic properties surfaces. Unlike scanning tunnel microscope(STM), can examine both conducting and non-conducting surfaces even through a layer of liquid, which allows you to work with organic molecules (DNA). The spatial resolution of an atomic force microscope depends on the size of the cantilever and the curvature of its tip. The resolution reaches atomic horizontally and significantly exceeds it vertically.

Oscillator antenna - On February 9, 2005, an oscillator antenna with dimensions of about 1 micron was obtained in the laboratory of Boston University. This device has 5,000 million atoms and is capable of oscillating at a frequency of 1.49 gigahertz, which allows it to transmit huge amounts of information.

Plasmons - collective vibrations of free electrons in a metal. A characteristic feature of plasmon excitation can be considered the so-called plasmon resonance, first predicted by Mie at the beginning of the 20th century. The wavelength of plasmon resonance, for example, for a spherical silver particle with a diameter of 50 nm is approximately 400 nm, which indicates the possibility of recording nanoparticles far beyond the diffraction limit (the radiation wavelength is many more sizes particles). At the beginning of 2000, thanks to rapid progress in the technology of manufacturing nano-sized particles, an impetus was given to the development of new area nanotechnology - nanoplasmonics. It turned out to be possible to transmit electromagnetic radiation along a chain of metal nanoparticles using the excitation of plasmon oscillations.

5.5 Robotics

Molecular rotors - synthetic nanoscale engines capable of generating torque when sufficient energy is applied to them.

Nanorobots - robots created from nanomaterials and comparable in size to a molecule, with the functions of movement, processing and transmission of information, and execution of programs. Nanorobots capable of creating copies of themselves, that is, self-reproduction, are called replicators. The possibility of creating nanorobots was discussed in his book “Machines of Creation” by the American scientist Eric Drexler. Issues of developing nanorobots and their components are discussed at specialized international conferences.

Molecular propellers - nano-sized molecules in the shape of a screw, capable of performing rotational movements due to their special form, similar to the shape of a macroscopic screw.

Since 2006, within the framework of the RoboCup project (football championship among robots), the “Nanogram Competition” nomination has appeared, in which the playing field is a square with a side of 2.5 mm. The maximum player size is limited to 300 microns.

Literature

1. www.olymp.ifmo.ru.

Definition of nanoparticles

The term nanoparticle or nanosized particle firmly entered the scientific lexicon about 20 years ago, but the nanoscale criterion is still the subject of many scientific discussions.

A nano-object is a physical object of research (and development), the dimensions of which are usually measured in nanometers.

Nanotechnology deals with both individual nano-objects and materials based on them, as well as processes at the nano-level. Nanomaterials include such materials as physical characteristics which are determined by the nanoobjects they contain.

Nanomaterials are divided into compact materials and nanodispersions; The first include the so-called “nanostructured” materials, i.e. materials that are isotropic in macro-composition, repeating elements, the structure of which is groupings (regions) with dimensions of several nanometers, sometimes tens of nanometers or more; in other words, nanostructured materials consist of nanoobjects directly in contact with each other. In contrast, nanodispersions consist of a dispersion medium (vacuum, gas, liquid or solid), in which nano-objects isolated from each other are distributed. The distance between nano-objects in nanodispersions can vary over a fairly wide range from tens of nanometers to fractions of a nanometer; in the latter case, we are dealing with nanopowders, where nano-objects are separated by thin (often monoatomic) layers of light atoms that prevent their agglomeration.

A nanoparticle is a quasi-zero-dimensional nanoobject in which all characteristic linear dimensions are of the same order of magnitude; As a rule, nanoparticles have a spheroidal shape; If a nanoparticle exhibits a pronounced ordered arrangement of atoms (or ions), then such nanoparticles are called nanocrystallites. Nanoparticles with a pronounced discrete system of energy levels are often called “quantum dots” or “artificial atoms”; most often they have the composition of typical semiconductor materials.

Classification of nanoparticles

According to the international convention IUPAC, the limiting (maximum) size of nanoparticles corresponds to 100 nm, although this value is purely arbitrary and is necessary only for formal classification. There are two types of nanoparticles: nanoclusters, or nanocrystals, and nanoparticles themselves. The first type includes particles of an ordered structure (often centrosymmetric) with a size of 1×5 nm, containing up to 1000 atoms, the second type includes nanoparticles with a size of 5×100 nm, consisting of 103×108 atoms. Filamentary and plate-like particles can contain much large quantity atoms and have one or even two linear sizes exceeding a threshold value, but their properties in a certain direction remain characteristic of a substance in a nanocrystalline state. If a nanoparticle has complex shape and structure, then it is not the linear size of the particle as a whole that is considered as characteristic, but the size of its structural element. Such particles are usually called nanostructures, and their linear dimensions can significantly exceed 100 nm.

Differences in the linear sizes of nanoparticles make it advisable to subdivide them into zero-, one-, two- and three-dimensional (0D, 1D, 2D and 3D nanoparticles, respectively). Zero-dimensional nanostructures include free and stabilized clusters, fullerenes and endofullerenes, and quantum dots. The class of one-dimensional nanostructures is represented by a much larger variety of nanoobjects: these are nanorods, nanothreads (whiskers), nanotubes and nanoribbons. Two-dimensional nanostructures include thin films up to hundreds of nanometers thick, heterostructures, Langmuir-Blodgett films, nanoplates, adsorption and self-assembled monolayers, as well as two-dimensional arrays of objects whose sizes are in the nanometer range. The class of three-dimensional nanostructures should include both nanoparticles themselves and nanoparticles in a shell, as well as nanocomposites and three-dimensional self-organized arrays of nanoobjects. Moreover, the composites themselves can include zero-, one- and two-dimensional objects, that is, they can be arrays quantum dots, filaments, multilayer films or layered compounds, as well as various combinations of these types of nanostructures. At the nanoscale, it turned out to be possible for the existence of structures of intermediate dimensions, the so-called. fractals and dendrimers that have self-similarity and were previously considered only as mathematical models.

In recent years, great efforts by researchers have been aimed at obtaining nanoparticles of predetermined shape and size, and therefore having certain physicochemical properties - many different synthetic approaches have been described, each of which has its own advantages, but is also not without certain disadvantages. Today, all methods for producing nanomaterials are divided into two large groups according to the type of formation of nanostructures: methods? bottom-up? (?Bottomup?) are characterized by the growth of nanoparticles or the assembly of nanoparticles from individual atoms; and the methods? top-down? (?Top-down?) are based on?crushing? particles up to nanosize.

Nanotechnology [Science, Innovation and Opportunity] Foster Lynn

13.2.1. Application of nanoparticles

13.2.1. Application of nanoparticles

Many readers probably remember that a few years ago, sunscreen was an opaque milky-white ointment, the color of which was explained by the presence of micron particles of zinc oxide in it, which absorbed the ultraviolet part of solar radiation harmful to the skin. Transparent creams are now being produced that are much more convenient and attractive to consumers. The commercial success of new cosmetic preparations is explained by the fact that they contain particles of the same zinc oxide, but crushed to nanometric sizes. Such particles still pass through most sunlight, but retain the ability to absorb dangerous waves in the UV region of the spectrum. Later, nanoparticles of another well-known white dye (titanium dioxide) began to be used for the same purposes, that is, simply replacing micron particles with nanometric ones made it possible to create a new and very successful commercial product in the cosmetics industry.

Changing the properties of titanium dioxide particles allowed them to find another important technical application in the so-called dye sensitization of the working substance of solar cells. The efficiency of light conversion by such batteries is determined primarily by the ability of substance particles to absorb solar radiation. It was discovered that titanium dioxide nanoparticles, due to their very large total area, absorb light thousands of times (!) stronger than conventional, bulk crystals of the same composition, not to mention the fact that solar cells with dye sensitization turned out to be much cheaper to produce than known photovoltaic ones silicon-based devices. Now nanomaterials of this type are increasingly used in industry, evidence of which was the organization of their industrial production in Australia (2001).

Another very important commercial market for nanoparticles is in semiconductor technology. We are talking about the process of so-called chemical mechanical planarization (CMP) in the production of chips (microcircuits), when the required components are applied to the surface of the wafer being processed at several points, which are then “smeared” over this surface in an even layer with almost atomic precision. Processing a large crystalline surface (up to 300 mm) with such incredible precision is a very complex technical problem that cannot be solved existing methods! In the new method, a suspension of nanoparticles is applied to the surface of the device, which are then used in a combined process of chemical removal and mechanical friction, resulting in the surface being “polished” with atomic precision. This process has proven highly effective at using nanoparticles of many common semiconductor materials (aluminum oxide, silicon oxide, cerium oxide), and as a result, the CMP market has grown from $250 million in 1996 to nearly $1 billion in 2000. At the same time, the production of initial components for the CMP process itself (suspensions of nanoparticles, polishing units) naturally became an independent sector of the materials market, and its volume in 2005 was about $800 million. Given the semiconductor industry's ongoing trend toward miniaturization and increased precision processing, you can be confident that the market for CMP-related products and services will continue to evolve.

The technologies mentioned above are known and already implemented, but it is worth mentioning that the process of commercialization and technical development of many other technologies based on the use of nanoparticles is currently underway. For example, professors Paul Alivisatos (University of California, Berkeley) and Munji Bawendi (University of Massachusetts) have proposed new processes for making semiconductor nanoparticles from materials such as cadmium selenide (CdSe) and cadmium telluride (TeSe). Particles of these substances, coated with a layer of zinc sulfide, acquire the ability to absorb light in the ultraviolet wavelength range and then emit light in the visible range, which is associated with the so-called quantum confinement effects, and the emission wavelength depends on the size of the nanoparticles used. Such sources are much superior to known emitters (based on fluorescent chemical dyes) in terms of stability and brightness of radiation, but what gives them particular value is that nanoparticles can be chemically bound to proteins, oligonucleotides, or simply small molecules. Nanoparticles give these compounds completely new functional characteristics and thereby open up to biological structures and molecules have huge prospects in medicine and biotechnology as fluorescent “tags”. Moreover, studies have shown that the emission wavelength of silicon nanocrystals (less than 4 nm in diameter) in the visible range also depends on the size of the crystals. The emitters created on this basis turned out to be much more efficient than fluorescent and other sources currently used in solid-state technology, which allows them to find many technical applications. [Nanoparticles of many substances demonstrate completely amazing properties, allowing them to be used as catalysts, etc. The reader can familiarize himself with this problem in the article by F. Ball “New Alchemy” in the journal “Chemistry and Life”, No. 1, 2006. Note translation]

As the size of crystallites decreases to nanometers, not only their physical but also chemical properties (in particular, catalytic activity) change significantly. a shining example What can the behavior of gold mean? It is known that in its normal bulk state, gold is chemically a fairly inert element. However, cerium dioxide particles deposited on the surface of gold in non-metallic form (in the form of nanoclusters) in very low concentrations (about 0.2–0.9 at.%) become extremely active catalysts for the well-known water gas shift reaction, in which carbon monoxide and water are converted into carbon dioxide and hydrogen. This reaction is key to the mechanism of action of fuel cells using hydrocarbon fuel, which in such cells is converted into hydrogen and carbon-containing products. A long-time dream of fuel cell designers and manufacturers has been to maximize hydrogen yield, that is, to minimize the amount of unreacted carbon monoxide, which is the “catalytic poison” of the electrocatalytic reaction within the cell itself. The use of nanoparticles with the specified and very small amounts of gold is extremely beneficial from an economic point of view, since the previously used catalysts contain noble metal reached 10 at. %.

Significant changes in the magnetic properties of matter during the transition to the nanoscale also open up very interesting prospects for researchers, allowing even hope for the possibility of creating so-called superparamagnets. Superparamagnetic nanoparticles in the absence of a magnetic field and at temperatures above the Curie point behave like ordinary magnets, that is, their magnetic moments are randomly located, but when applied external field they easily “line up” along the field, creating a powerful overall magnetic moment. This mechanism can be used for a variety of purposes, including the formation of images based on magnetic resonance(magnetic resonance imaging, MRI). The method has been theoretically known for a long time, but its practical application was limited by the fact that the contrast of the resulting images was provided by only a very small number of natural substances contained in the body (for example, deoxyhemoglobin). The efficiency of the method and image contrast can be significantly increased through the use of superparamagnetic iron oxide nanoparticles, called SPION (superparamagnetic iron oxide, SPION). Such particles, made on the basis of magnetite (Fe 3 O 4), maghemite (gamma Fe 2 O 3) or combinations thereof, naturally must be coated with a layer of a substance that increases stability colloidal system and ensuring biological compatibility with the body. The advantage of the described magnetic resonance method is that it allows you to obtain clear images fabrics containing a large number of fluids (for example, affected organs or cancerous tumors). Already, such nanoparticles are commercially produced by several organizations. It is understood that the surface of SPION particles can be further chemically modified to impart the ability to interact with contrast agents, specific tissues or cell types. This approach is very promising, which has already led to the emergence of actively developing areas of various biomedical research.

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Nanoparticle

Nanoparticle

Nanoparticle

Spherical or capsule-shaped structures, the size of which varies from tenths to 100 nm. The properties of nanoparticles differ from the properties of bulk matter consisting of the same atoms. Nanoparticles include objects containing from 10 to tens of thousands of atoms. Such a large scatter of sizes is determined by the fact that it is difficult to establish a clear upper limit on the size that determines changes in the deformation, electrical, magnetic, optical and other properties of these small-sized solid objects. Many nanoparticles have a cavity, that is, a kind of reservoir in which an antitumor agent, a label or marker, or “reporter” chemicals can be placed, indicating whether the medicinal product therapeutic effect. It is also possible to attach any substances or objects to the surface of the nanoparticle, for example, antibodies, medicines, radiopharmaceuticals or reporters. Most man-made nanoparticles are small enough to pass through blood capillaries and enter cells.

Explanatory English-Russian dictionary on nanotechnology. - M.. V.V. Arslanov. 2009.

Synonyms:

See what a “nanoparticle” is in other dictionaries:

Nanoparticle- (English nanoparticle) an isolated solid-phase object that has a clearly defined boundary with the environment, the dimensions of which in all three dimensions range from 1 to 100 nm. Description Nanoparticles are one of the most common terms for ... Wikipedia

nanoparticle- noun, number of synonyms: 1 particle (128) ASIS Dictionary of Synonyms. V.N. Trishin. 2013… Synonym dictionary

nanoparticle- A particle of a substance whose dimensions are measured in nanometers Biotechnology topics EN nanoparticle ... Technical Translator's Guide

nanoparticle- nanotechnological particle tech. Source: http://www.businesspress.ru/newspaper/article mId 37 aId 422686.html … Dictionary of abbreviations and abbreviations

nanoparticle- 3.7 nanoparticle: Solid, liquid or multiphase object, including a microorganism, less than or equal to 100 nm in size. Source …

nanoparticle- The term nanoparticle The term in English nanoparticle Synonyms Abbreviations Related terms"smart" materials, biocompatible coatings, hydrothermal synthesis, electrical double layer, dispersion-hardening alloys, capsid, cluster... encyclopedic Dictionary nanotechnology

nanoparticle- nanoparticles, s... Together. Apart. Hyphenated.

artificially created nanoparticle- 2.8 engineered nanoparticle: Nanoparticle specially created with specified characteristics. Source … Dictionary-reference book of terms of normative and technical documentation

GOST R 8.712-2010: State system for ensuring the uniformity of measurements. Dispersive characteristics of aerosols and suspensions in the nanometer range. Measurement methods. Basic provisions- Terminology GOST R 8.712 2010: State system ensuring uniformity of measurements. Dispersive characteristics of aerosols and suspensions in the nanometer range. Measurement methods. Basic provisions of the original document: 3.10 aerodynamic diameter... ... Dictionary-reference book of terms of normative and technical documentation

GOST R 54597-2011: Air in the working area. Ultrafine aerosols, aerosols of nanoparticles and nanostructured particles. Characterization and assessment of inhalation exposure- Terminology GOST R 54597 2011: Air working area. Ultrafine aerosols, aerosols of nanoparticles and nanostructured particles. Characterization and assessment of exposure by inhalation original document: 2.4 agglomerate (aerosols)… … Dictionary-reference book of terms of normative and technical documentation

The modern trend towards miniaturization has shown that a substance can have completely new properties if you take a very small particle of this substance. Particles ranging in size from 1 to 100 nanometers are commonly referred to as “nanoparticles.” For example, it turned out that nanoparticles of some materials have very good catalytic and adsorption properties. Other materials show amazing optical properties For example, ultrathin films of organic materials are used to produce solar cells. Such batteries, although they have a relatively low quantum efficiency, are cheaper and can be mechanically flexible. It is possible to achieve the interaction of artificial nanoparticles with natural nano-sized objects - proteins, nucleic acids, etc. Carefully purified nanoparticles can self-assemble into certain structures. This structure contains strictly ordered nanoparticles and also often exhibits unusual properties.

Nanoobjects are divided into 3 main classes: three-dimensional particles obtained by explosion of conductors, plasma synthesis, reduction of thin films, etc.; two-dimensional objects - films produced by molecular deposition, CVD, ALD, ion deposition, etc.; one-dimensional objects - whiskers, these objects are obtained by the method of molecular layering, introducing substances into cylindrical micropores, etc. There are also nanocomposites - materials obtained by introducing nanoparticles into any matrices. At the moment, only the microlithography method has been widely used, making it possible to obtain flat island objects with a size of 50 nm on the surface of matrices; it is used in electronics; The CVD and ALD method is mainly used to create micron films. Other methods are mainly used for scientific purposes. Particularly noteworthy are the ionic and molecular layering methods, since with their help it is possible to create real monolayers.

A special class consists of organic nanoparticles of both natural and artificial origin.

Definitions and terminology

The often used definition of nanotechnology as a set of methods for working with objects smaller than 100 nanometers does not accurately describe both the object and the difference between nanotechnology and traditional technologies and scientific disciplines. Nanotechnology objects, on the one hand, can have characteristic dimensions of the specified range:

• nanoparticles, nanopowders (objects whose three characteristic sizes are in the range of up to 100 nm);
• nanotubes, nanofibers (objects whose two characteristic sizes are in the range of up to 100 nm);
• nanofilms (objects with one characteristic size in the range of up to 100 nm).

On the other hand, nanotechnology objects can be macroscopic objects, the atomic structure of which is controlledly created with resolution at the level of individual atoms.

Nanotechnologies are qualitatively different from traditional disciplines, since at such scales the usual, macroscopic technologies for handling matter are often inapplicable, and microscopic phenomena, negligibly weak on conventional scales, become much more significant: the properties and interactions of individual atoms and molecules or aggregates of molecules, quantum effects.

In practical terms, these are technologies for the production of devices and their components necessary for the creation, processing and manipulation of atoms, molecules and particles whose sizes range from 1 to 100 nanometers. However, nanotechnology is now in its early stages of development, since the major discoveries predicted in this field have not yet been made. Nevertheless, ongoing research is already yielding practical results. Use of advanced nanotechnology scientific results allows us to classify it as high technology.

When working with such small dimensions, quantum effects and effects of intermolecular interactions, such as van der Waals interactions, appear. Nanotechnology and, in particular, molecular technology- new areas, very little explored. Development modern electronics is moving towards reducing the size of devices. On the other side, classical methods production approaches its natural economic and technological barrier, when the size of the device does not decrease much, but the economic costs increase exponentially. Nanotechnology is the next logical step in the development of electronics and other high-tech industries.

Story

Many sources, primarily English-language ones, associate the first mention of methods that would later be called nanotechnology with Richard Feynman’s famous speech “There’s Plenty of Room at the Bottom,” made by him in 1959 in California Institute of Technology at the annual meeting of the American Physical Society. Richard Feynman suggested that it was possible to mechanically move single atoms using a manipulator of the appropriate size, at least such a process would not contradict the laws of physics known today.

He suggested doing this manipulator in the following way. It is necessary to build a mechanism that would create a copy of itself, only an order of magnitude smaller. The created smaller mechanism must again create a copy of itself, again an order of magnitude smaller, and so on until the dimensions of the mechanism are commensurate with the dimensions of the order of one atom. In this case, it will be necessary to make changes in the structure of this mechanism, since the gravitational forces acting in the macrocosm will have less and less influence, and the forces of intermolecular interactions and van der Waals forces will increasingly influence the operation of the mechanism. The last stage - the resulting mechanism will assemble its copy from individual atoms. In principle, the number of such copies is unlimited; it will be possible to create any number of such machines in a short time. These machines will be able to assemble macro-things in the same way, by atomic assembly. This will make things much cheaper - such robots (nanorobots) will need to be given only the required number of molecules and energy, and write a program to assemble the necessary items. So far, no one has been able to refute this possibility, but no one has yet managed to create such mechanisms. The fundamental disadvantage of such a robot is the fundamental impossibility of creating a mechanism from a single atom.

The ideas presented by Feynman in his lecture about how to create and use such manipulators coincide almost textually with fantastic story the famous Soviet writer Boris Zhitkov’s “Mikroruki”, published in 1931. But not only. In the well-known work of the Russian writer N. Leskov “Lefty” there is an interesting fragment:

“If,” he says, “there was a better microscope, which magnifies five million times, then you would deign,” he says, “to see that on each horseshoe the name of the artist is displayed: which Russian master made that horseshoe.”

Magnification of 5,000,000 times is provided by modern electron and atomic force microscopes, which are considered the main tools of nanotechnology, thus the literary hero Lefty can be considered the first nanotechnologist in history.

The term “nanotechnology” was first used by Norio Taniguchi in 1974. He used this term to describe the production of products several nanometers in size. In the 1980s, the term was used by Eric K. Drexler in his books Engines of Creation: The Coming Era of Nanotechnology and Nanosystems: Molecular Machinery, Manufacturing, and Computation. A central place in his research was played by mathematical calculations, with the help of which it was possible to analyze the operation of devices several nanometers in size. In principle, the creation of nanomanipulators could lead to a “gray sludge” scenario.

Fundamental provisions

Atomic force microscopy

One of the methods used to study nanoobjects is atomic force microscopy. Using an atomic force microscope (AFM), you can not only see individual atoms, but also selectively influence them, in particular, move atoms along the surface. Scientists have already managed to create two-dimensional nanostructures on the surface using this method. For example, in research center IBM, by sequentially moving xenon atoms on the surface of a nickel single crystal, employees were able to lay out three letters of the company logo using 35 xenon atoms (D. M. Eigler, E. K. Schweizer, Nature, vol. 344, p. 524, 1990).

When performing such manipulations, a number of technical difficulties arise. In particular, it is necessary to create ultra-high vacuum conditions (10-11 torr), it is necessary to cool the substrate and microscope to ultra-low temperatures (4-10 K), the surface of the substrate must be atomically clean and atomically smooth, for which they are used special methods her preparations. The substrate is cooled in order to reduce the surface diffusion of deposited atoms.

Self-organization of nanoparticles

One of the most important questions facing nanotechnology is how to force molecules to group in a certain way, to self-organize, in order to ultimately obtain new materials or devices. This problem is dealt with by a branch of chemistry—supramolecular chemistry. It studies not individual molecules, but interactions between molecules, which, when organized in a certain way, can give rise to new substances. It is encouraging that similar systems and similar processes actually exist in nature. Thus, biopolymers are known that can organize into special structures. One example is proteins, which not only can fold into a globular form, but also form complexes - structures that include several protein molecules (proteins). There is already a synthesis method that uses the specific properties of the DNA molecule. Complementary DNA is taken, a molecule A or B is connected to one of the ends. We have 2 substances: —-A and —-B, where —- is a symbolic image single molecule DNA. Now, if you mix these 2 substances, between two single strands of DNA, hydrogen bonds, which will attract molecules A and B to each other. Let us roughly depict the resulting connection: ====AB. The DNA molecule can be easily removed after the process is completed.

The problem of agglomerate formation

Particles with sizes on the order of nanometers, or nanoparticles as they are called in scientific circles, have one property that greatly hinders their use. They can form agglomerates, that is, stick to each other. Since nanoparticles are promising in the ceramics and metallurgy industries, this problem must be solved. One possible solution is the use of dispersant substances, such as ammonium citrate (aqueous solution), imidazoline, oleic alcohol (insoluble in water). They can be added to a medium containing nanoparticles. This is discussed in more detail in the source “Organic Additives And Ceramic Processing, D. J. Shanefield, Kluwer Academic Publ., Boston (English).

Latest achievements

Nanomaterials

Materials developed based on nanoparticles with unique characteristics, resulting from the microscopic sizes of their components.

• Carbon nanotubes are extended cylindrical structures with a diameter from one to several tens of nanometers and a length of up to several centimeters, consisting of one or several hexagonal graphite planes (graphenes) rolled into a tube and usually ending in a hemispherical head.

• Fullerenes are molecular compounds that belong to the class of allotropic forms of carbon (others are diamond, carbyne and graphite) and are convex closed polyhedra composed of an even number of tricoordinated carbon atoms.

• Graphene is a monolayer of carbon atoms obtained in October 2004 at The University Of Manchester. Graphene can be used as a molecular detector (NO2), allowing one to detect the arrival and departure of single molecules. Graphene has high mobility at room temperature, due to which, as soon as the problem of the formation of a band gap in this semimetal is solved, graphene is being discussed as a promising material that will replace silicon in integrated circuits.

• Nanobatteries - at the beginning of 2005, Altair Nanotechnologies (USA) announced the creation of an innovative nanotechnological material for the electrodes of lithium-ion batteries. Batteries with Li4Ti5O12 electrodes have a charging time of 10-15 minutes. In February 2006, the company began producing batteries at its Indiana plant. In March 2006, Altairnano and Boshart Engineering entered into an agreement to jointly develop an electric vehicle. In May 2006, tests of automobile nanobatteries were successfully completed. In July 2006, Altair Nanotechnologies received its first order to supply lithium-ion batteries for electric vehicles.

Nanomedicine and chemical industry

A direction in modern medicine based on the use of the unique properties of nanomaterials and nanoobjects to track, design and modify human biological systems at the nanomolecular level.

• DNA nanotechnology - uses the specific bases of DNA molecules and nucleic acids to create clearly defined structures on their basis.

• Industrial synthesis of drug molecules and pharmacological preparations of a well-defined form (bis-peptides).

Computers and microelectronics

• Central processing units - On October 15, 2007, Intel announced the development of a new prototype processor containing the smallest structural element measuring approximately 45 nm. In the future, the company intends to reach the size of structural elements up to 5 nm. Intel's main competitor, AMD, has also long been using nanotechnological processes developed jointly with IBM to produce its processors. A characteristic difference from Intel's developments is the use of an additional insulating SOI layer, which prevents current leakage due to additional insulation of the structures that form the transistor. There are already working samples of processors with 45 nm transistors and prototypes with 32 nm;

• Hard drives - in 2007, Peter Grunberg and Albert Furth received the Nobel Prize in Physics for the discovery of the GMR effect, which allows data to be recorded on hard drives with atomic information density;

• An atomic force microscope is a high-resolution scanning probe microscope based on the interaction of a cantilever needle (probe) with the surface of the sample under study. Typically, interaction refers to the attraction or repulsion of a cantilever from a surface due to van der Waals forces. But when using special cantilevers, it is possible to study the electrical and magnetic properties of the surface. Unlike a scanning tunneling microscope (STM), it can examine both conducting and non-conducting surfaces even through a layer of liquid, which makes it possible to work with organic molecules (DNA). The spatial resolution of an atomic force microscope depends on the size of the cantilever and the curvature of its tip. The resolution reaches atomic horizontally and significantly exceeds it vertically;

• Oscillator antenna - On February 9, 2005, an oscillator antenna with dimensions of about 1 micron was obtained in the Boston University laboratory. This device has 5,000 million atoms and is capable of oscillating at a frequency of 1.49 gigahertz, which allows it to transmit huge amounts of information;

• Plasmons are collective vibrations of free electrons in a metal. A characteristic feature of plasmon excitation can be considered the so-called plasmon resonance, first predicted by Mie at the beginning of the 20th century. The plasmon resonance wavelength, for example, for a spherical silver particle with a diameter of 50 nm is approximately 400 nm, which indicates the possibility of recording nanoparticles far beyond the diffraction limit (the radiation wavelength is much larger than the particle size). At the beginning of 2000, thanks to rapid progress in the technology of manufacturing nanosized particles, an impetus was given to the development of a new field of nanotechnology - nanoplasmonics. It turned out to be possible to transmit electromagnetic radiation along a chain of metal nanoparticles using the excitation of plasmon oscillations.

Robotics

• Molecular rotors are synthetic nanoscale motors capable of generating torque when enough energy is applied to them;

• Nanorobots are robots created from nanomaterials and comparable in size to a molecule, with the functions of movement, processing and transmission of information, and execution of programs. Nanorobots capable of creating copies of themselves, i.e. self-reproduction are called replicators. The possibility of creating nanorobots was discussed in his book “Machines of Creation” by the American scientist Eric Drexler. At present, electromechanical nanodevices with limited mobility have already been created, which can be considered prototypes of nanorobots;

• Molecular propellers are nano-sized molecules in the shape of a screw, capable of performing rotational movements due to their special shape, similar to the shape of a macroscopic screw;

• Since 2006, within the framework of the RoboCup project (football among robots), the “Nanogram Competition” nomination has appeared, in which the playing field is a square with a side of 2.5 mm. The maximum player size is limited to 300 microns.

Nanotechnology industry

In 2004, global investment in nanotechnology development almost doubled compared to 2003 and reached $10 billion. Private donors—corporations and foundations—accounted for approximately $6.6 billion in investments, government agencies- about $3.3 billion. The world leaders in terms of total investment in this area are Japan and the USA. Japan increased spending on the development of new nanotechnologies by 126% compared to 2003 (total investment amounted to $4 billion), the USA - by 122% ($3.4 billion). Currently (2008), Russian funding for the development of nanotechnology has reached the level of the United States approximately, 1945-1955.

State Corporation "Russian Nanotechnology Corporation" (RUSNANO)

RUSNANO is a large-scale state project, ultimate goal which is the transfer of the country to an innovative path of development and Russia’s entry into the ranks of the leaders in the global nanotechnology market. Today the Corporation has concentrated some of the best specialists in the country who are capable of establishing mutually beneficial cooperation between science, business and government. This is the main condition for success.

A.B. Chubais, General Director of RUSNANO

Russian Nanotechnology Corporation was founded in 2007. federal law No. 139-FZ for implementation public policy in the field of nanotechnology.

The corporation solves this problem by acting as a co-investor in nanotechnology projects with significant economic or social potential. Financial participation of the corporation in early stages projects reduces the risks of its private investor partners.

The corporation is involved in the creation of nanotechnology infrastructure, such as centers collective use, business incubators and early investment funds. To support funded projects, the Corporation implements scientific and educational programs, and also popularizes nanotechnology research and development. The corporation chooses priority areas investing based on long-term forecasts development (foresights), in the development of which the Corporation attracts leading Russian and world experts.

Supporting the entry of Russian companies into foreign markets and strengthening their mutually beneficial international connections, The Corporation is developing cooperation with the world's leading nanotechnology centers and organizing an annual international forum on nanotechnology.