As stated above, due to the location of the nanoworld on the borders of classical physics and quantum mechanics, its objects can no longer be considered as absolutely identical and statistically indistinguishable. All of them are individual, and one nanoparticle differs from another in composition, structure, and many other parameters (for example, C 60 and C 70 fullerenes). It is impossible to ignore the presence of inhomogeneities and irregularities in the structure of an object and use average, integral characteristics to describe it, as is customary in classical physics. The peculiarity of nano-objects lies in the fact that their size is commensurate with the radius of action of the forces of interatomic interaction, i.e. with the distance at which the atoms of the body must be removed so that their interaction does not affect its properties to a noticeable extent. Due to this feature, nanobodies interact with each other and with the environment differently than macrobodies. The science that studies the properties of various nanostructures, as well as the development of new ways to obtain, study and modify them, is called nanochemistry. It explores the production and properties of various nanosystems. Nanosystems are a set of bodies surrounded by a gas or liquid medium. Such bodies can be polyatomic clusters and molecules, nanodroplets and nanocrystals. These are intermediate forms between atoms and macroscopic bodies. The size of the systems remains in the range of 0.1-100 nm.
One of the priority tasks of this area of knowledge is to establish a relationship between the size of a nanoparticle and its properties. In nanochemistry, the role of quantum size effects, causing a change in the properties of a substance depending on the size of the particles and the number of atoms or molecules in them. The role of size effects is so great that attempts are being made to create tables of dependence of the properties of clusters and nanoparticles on their size and geometry, similar to the Periodic Table. Quantum size effects determine such properties of a substance as heat capacity, electrical conductivity, some optical properties, and so on.
Changes in characteristics are associated with two main reasons: an increase in the surface fraction and a change in the electronic structure due to quantum effects. The properties of atoms located near the surface differ from the properties of atoms located in the bulk of the material; therefore, the particle surface can be considered as a special state of matter. The larger the proportion of atoms located on the surface, the stronger the effects associated with the surface (Fig. 9).
Rice. 9. Change in the ratio of "surface" atoms (1) and those in the bulk of the material (2) depending on the particle size.
Features of the electronic structure of nanoobjects are explained by the enhancement of quantum properties associated with a decrease in size. The unusual properties of nanostructures hinder their trivial technical use and at the same time open up completely unexpected technical prospects.
Significant differences in the properties of nanoparticles begin to appear at particle sizes below 100 nm. From an energy point of view, a decrease in particle size leads to an increase in the role of surface energy, which leads to a change in the physical and chemical properties of small objects.
Nanochemistry Research Objects are bodies with such a mass that their equivalent size (the diameter of a sphere, the volume of which is equal to the volume of the body) remains within the nanointerval (0.1 - 100 nm). Conventionally, nanochemistry can be divided into theoretical, experimental, and applied (Fig. 10).
Rice. 10. Structure of nanochemistry
Theoretical nanochemistry develops methods for calculating the behavior of nanobodies, taking into account such parameters of the state of particles as spatial coordinates and velocities, mass, characteristics of the composition, shape and structure of each nanoparticle.
Experimental nanochemistry develops in three directions. As part of first, which is quite consistent with the section of analytical chemistry, supersensitive physical and chemical methods are being developed and used that make it possible to judge the structure of molecules and clusters, including tens and hundreds of atoms. Second direction explores phenomena under local (local) electrical, magnetic or mechanical effects on nanobodies, implemented with the help of nanoprobes and special manipulators. In this case, the goal is to study the interaction of individual gas molecules with nanobodies and nanobodies with each other, to reveal the possibility of internal rearrangements without destruction of molecules and clusters and with their decay. This area is also interested in the possibility of "atomic assembly" of a nanobody of the desired appearance when atoms move over the surface of the substrate (the base material, the surface of which is subjected to various types of processing, resulting in the formation of layers with new properties or the growth of a film of another material). As part of third directions determine the macrokinetic characteristics of nanobodies collectives and their distribution functions according to state parameters.
Applied Nanochemistry includes: the development of theoretical foundations for the use of nanosystems in engineering and nanotechnology, methods for predicting the development of specific nanosystems in the conditions of their use, as well as the search for optimal methods of operation ( technical nanochemistry); creation of theoretical models of the behavior of nanosystems during the synthesis of nanomaterials and the search for optimal conditions for their production ( synthetic nanochemistry); study of biological nanosystems and creation of methods for using nanosystems for medicinal purposes ( medical nanochemistry); development of theoretical models for the formation and migration of nanoparticles in the environment and methods for purifying natural waters or air from nanoparticles ( ecological nanochemistry).
Speaking about the sizes of the objects of study, it should be taken into account that the boundaries of the nanointerval in chemistry are conditional. The properties of a body are sensitive to its size to varying degrees. Some of the properties lose their specificity at a size of more than 10 nm, others - more than 100 nm. Therefore, in order to exclude fewer properties from consideration, the upper limit of the nanointerval is assumed to be 100 nm.
In a given interval, any property specifically depends on its mass and volume. Therefore, the object of nanochemistry can be considered objects in which interactions each atom with all other atoms are significant.
Nanochemistry objects can be classified according to different features. For example, by phase state(Table 1).
Geometrically(dimensions) nano-objects can be classified in different ways. Some researchers propose to characterize the dimensionality of an object by the number of dimensions in which the object has macroscopic dimensions. Others take as a basis the number of nanoscopic measurements.
In table. Table 2 lists the main objects of nanochemical research (nanoparticles and their corresponding nanosystems).
The classification of nanoobjects according to their dimension is important not only from a formal point of view. Geometry significantly affects their physicochemical properties. Let us consider some of the most priority objects of nanochemistry research.
Nanoparticles from atoms of inert gases. They are the simplest nanoobjects. Atoms of inert gases with completely filled electron shells weakly interact with each other through van der Waals forces. When describing such particles, the model of hard spheres is used (Fig. 11). The binding energy, that is, the energy spent on detaching an individual atom from a nanoparticle, is very small, so the particles exist at temperatures not higher than 10–100 K.
Rice. 11. Nanoparticles of 16 argon atoms.
Metal nanoparticles. In metal clusters of several atoms, both covalent and metallic types of bonds can be realized (Fig. 12). Metal nanoparticles are highly reactive and are often used as catalysts. Metal nanoparticles can take the correct shape - octahedron, icosahedron, tetradecahedron.
Rice. 12. Nanoparticles consisting of atoms of platinum (white spheres) and copper (gray)
Fullerenes. They are particles hollow inside, formed by polyhedrons of carbon atoms bound by a covalent bond. A special place among fullerenes is occupied by a particle of 60 carbon atoms - C 60 , resembling a microscopic soccer ball (Fig. 13).
Rice. 13. Fullerene C 60 molecule
Fullerenes are widely used: in the creation of new lubricants and anti-friction coatings, new types of fuel, ultra-hard diamond-like compounds, sensors and paints.
carbon nanotubes. These are hollow molecular objects consisting of approximately 1,000,000 carbon atoms and representing single-layer or multilayer tubes with a diameter of 1 to 30 nm and a length of several tens of microns. On the nanotube surface, carbon atoms are located at the vertices of regular hexagons (Fig. 14).
Rice. 14. Carbon nanotubes.
Nanotubes have a number of unique properties, due to which they are widely used mainly in the creation of new materials, electronics, and scanning microscopy. The unique properties of nanotubes: high specific surface area, electrical conductivity, and strength make it possible to create effective catalyst carriers for various processes on their basis. For example, nanotubes are used to make new energy sources - fuel cells that can last many times longer than simple batteries of a similar size. For example, nanotubes with palladium nanoparticles can compactly store hydrogen thousands of times their volume. Further development of fuel cell technology will allow them to store hundreds and thousands of times more energy than modern batteries.
Ionic clusters. They represent a classic picture characteristic of an ionic bond in the crystal lattice of sodium chloride (Fig. 15). If an ionic nanoparticle is large enough, then its structure is close to that of a bulk crystal. Ionic compounds are used in the creation of high-resolution photographic films, molecular photodetectors, and in various fields of microelectronics and electro-optics.
Rice. 15. NaCl cluster.
fractal clusters. These are objects with a branched structure (Fig. 16): soot, colloids, various aerosols and aerogels. A fractal is an object in which, with increasing magnification, one can see how the same structure is repeated in it at all levels and on any scale.
Fig.16. fractal cluster
Molecular clusters(supramolecular systems). Clusters of molecules. Most clusters are molecular. Their number and variety is enormous. In particular, many biological macromolecules belong to molecular clusters (Figs. 17 and 18).
Rice. 17. Molecular cluster of ferredoxin protein.
Rice. 18. High spin molecular clusters
Nanochemistry
Chemistry and pharmacology
Nanoscience emerged as an independent discipline only in the last 7-10 years. The study of nanostructures is a common direction for many classical scientific disciplines. Nanochemistry occupies one of the leading places among them, as it opens up almost unlimited possibilities for the development, production and research of...
FEDERAL AGENCY FOR EDUCATION OMSK STATE PEDAGOGICAL UNIVERSITY FACULTY OF CHEMISTRY AND BIOLOGY
DEPARTMENT OF CHEMISTRY AND METHODS OF TEACHING CHEMISTRY
Nanochemistry
Completed by: student 1-XO Kuklina N.E.
Checked by: candidate of chemical sciences, associate professor Bryansky B.Ya.
Omsk 2008
§one. The history of the formation of nanoscience………………………………………………………………3
§2. Basic concepts of nanoscience……………………………………………………………….5
§3. Features of the structure and behavior of some nanoparticles………………………………8
§4. Types of applied use of nanochemistry………………………………………….....9
§five. Methods for obtaining nanoparticles……………………………………………………………..10
§6. Nanomaterials and prospects for their application………………………………………...11
Sources of information……………………………………………………………………………………………13
§one. The history of the formation of nanoscience
1905 Albert Einstein theoretically proved that the size of a sugar molecule is p and veins are 1 nanometer.
1931 German physicists Ernst Ruska and Max Knoll created an electronic microphone about scope providing 10 15 -fold increase.
1932 Dutch professor Fritz Zernike invented the phase-contrast mi to roscope a variant of an optical microscope that improved the quality of displaying the details of images a zheniya, and investigated living cells with its help.
1939 Siemens, where Ernst Ruska worked, produced the first commercial electron microscope with a resolution of 10 nm.
1966 American physicist Russell Young, who worked at the National Bureau of n darts, invented the engine used today in scanning tunnel mics about scopes and for positioning nanotools with an accuracy of 0.01 angstroms (1 nanometer = 10 angstroms).
1968 Alfred Cho, executive vice president of Bell, and John Arthur, an employee of its semiconductor research division, substantiated the theoretical possibility of using nanotechnologies to solve problems of surface treatment and achieve atomic precision in the creation of electronic devices.
1974 Japanese physicist Norio Taniguchi, who worked at the University of Tokyo, proposed the term "nanotechnology" (the process of separation, assembly and change of mother a catching by exposing them to one atom or one molecule), which quickly gained popularity in scientific circles.
1982 At the IBM Zurich Research Center for Physicists Gerd Binnig and Ge n Rich Rohrer created the scanning tunneling microscope (STM), which makes it possible to build a three-dimensional picture of the arrangement of atoms on the surfaces of conductive materials.
1985 Three American chemists: Rice University professor Richard Smalley, as well as Robert Carl and Harold Kroto discovered fullerenes molecules consisting I consisting of 60 carbon atoms arranged in the form of a sphere. These scientists were also able to measure a 1 nm object for the first time.
1986 Gerd Binnig developed the scanning atomic force probe micr about scope, which finally made it possible to visualize the atoms of any materials (not only about leading), as well as manipulate them.
19871988 At the Research Institute "Delta" under the direction of P.N. Luskinovich, the first Russian nanotechnological installation was launched, which carried out the directed departure of particles from the tip of the microscope probe under the influence of heating.
1989 Scientists Donald Eigler and Erhard Schwetzer of the California IBM Science Center managed to lay out 35 atoms of xenon on a nickel crystal with the name of their company.
1991 Japanese professor Sumio Lijima, who worked at NEC, and with used fullerenes to create carbon tubes (or nanotubes) with a diameter of 0.8 nm.
1991 The first nanotechnology program of the National Science Foundation was launched in the USA. The government of Japan has also taken up similar activities.
1998 Cees Dekker, a Dutch professor at Delfts University of Technology, created a transistor based on nanotubes. To do this, he had to be the first in the world to change e measure the electrical conductivity of such a molecule.
2000 German physicist Franz Gissible saw subatomic particles in silicon. His colleague Robert Magerle proposed the technology of nanotomography creation of three R image of the internal structure of matter with a resolution of 100 nm.
2000 The US government opened the National Nanotechnology Institute and initiative (NNI). The US budget allocated 270 million dollars for this direction, commercial e Russian companies invested 10 times more in it.
2002 Cees Dekker combined a carbon tube with DNA, getting a single nano is khanism.
2003 Professor Feng Liu from the University of Utah, using the achievements of Franz Gissible, using an atomic microscope, built images of the orbits of electrons by analyzing their perturbations as they move around the nucleus.
§2. Basic concepts of nanoscience
Nanoscience emerged as an independent discipline only after d nie 7-10 years. The study of nanostructures is a common direction for many classical scientific disciplines. Nanochemistry occupies one of the leading places among them, as it opens up practically unlimited possibilities for the development, production and research of new nanomaterials with desired properties, often superior in quality to natural materials.
Nanochemistry - is a science that studies the properties of various nanoparticles t ruktur, as well as the development of new methods for their production, study and modification.
The priority task of nanochemistry isEstablishing a relationship between the nanometer size a stice and its properties.
Nanochemistry Research Objectsare bodies with such a mass that their equivalent and the valence size remains within the nanorange (0.1 100 nm).
Nanoscale objects occupy an intermediate position between bulk materials on the one hand, and atoms and molecules on the other. The presence of such b projects in materials gives them new chemical and physical properties. Nanoobjects are an intermediate and connecting link between the world in which the laws about ny of quantum mechanics, and the world in which the laws of classical physics operate.
Characteristic sizes of objects of the surrounding world
Nanochemistry investigates the production and properties of various nanosystems. Nanosystems are a set of bodies surrounded by a gas or liquid medium. Such t e Polyatomic clusters and molecules, nanodroplets and nanocrystals can be used as lamas. These are intermediate forms between atoms and macroscopic bodies. Systems size about with melts within 0.1 100 nm.
Classification of objects of nanochemistry by phase state
|
Phase state |
single atoms |
Clusters |
Nanoparticles |
Compact matter |
|
Diameter, nm |
0,1-0,3 |
0,3-10 |
10-100 |
Over 100 |
|
Number of atoms |
1-10 |
10-10 6 |
10 6 -10 9 |
Over 10 9 |
The range of objects studied by nanochemistry is constantly expanding. Chemists have always sought to understand what the features of nanometer-sized bodies are. This led to the rapid development of colloidal and macromolecular chemistry.
In the 80-90s of the XX century, thanks to the methods of electronic, atomic force and that n microscopy, it was possible to observe the behavior of metal nanocrystals and e organic salts, protein molecules, fullerenes and nanotubes, and in recent years t a These observations have become widespread.
Objects of nanochemical research
|
Nanoparticles |
Nanosystems |
|
Fullerenes |
Crystals, solutions |
|
tubulenes |
Aggregates, solutions |
|
Protein molecules |
Solutions, crystals |
|
polymer molecules |
Sols, gels |
|
Nanocrystals of inorganic e creatures |
Aerosols, colloidal solutions, precipitation |
|
Micelles |
Colloidal solutions |
|
Nanoblocks |
Solids |
|
Langmuir films Blodget |
Bodies with a film on the surface |
|
Clusters in gases |
Aerosols |
|
Nanoparticles in layers of various e creatures |
Nanostructured films |
Thus, the following main characteristics of nanochemistry can be distinguished:
- The geometric dimensions of objects lie on the nanometer scale;
- Manifestation of new properties by objects and their sets;
- Possibility of control and precise manipulation of objects;
- Objects and devices assembled on the basis of objects receive new consumers bsky properties.
§3. Features of the structure and behavior of some nanoparticles
Nanoparticles from atoms of inert gasesare the simplest nanoobjects b projects. Atoms of inert gases with completely filled electron shells weakly interact with each other through van der Waals forces. When describing such particles, the model of hard spheres is used.
Metal nanoparticles. In metallic clusters of several atoms, both covalent and metallic types of bonds can be realized. Metal nanoparticles are highly reactive and are often used as catalysis. a tori. Metal nanoparticles usually take the correct shape octahedron, ikos a hedra, tetradecahedron.
fractal clustersthese are objects with a branched structure: soot, co l loids, various aerosols and aerogels. A fractal is such an object in which, when increasing with melting magnification, you can see how the same structure is repeated in it at all levels and at any scale.
Molecular clustersclusters consisting of molecules. Most clast e ditch are molecular. Their number and variety are enormous. In particular, to the molecules at Many biological macromolecules belong to polar clusters.
Fullerenes are hollow inside particles formed by polyhedral n nicknames of carbon atoms linked by a covalent bond. A special place among fullers e new occupied by a particle of 60 carbon atoms C 60 resembling a microscopic soccer ball.
Nanotubes these are hollow molecules inside, consisting of approximately 1,000,000 at about mov of carbon and representing single-layer tubes with a diameter of about a nanometer and a length of several tens of microns. On the nanotube surface, carbon atoms are dispersed about lie at the vertices of regular hexagons.
§4. Applied Uses of Nanochemistry
Conventionally, nanochemistry can be divided into:
- theoretical
- experimental
- Applied
Theoretical nanochemistrydevelops methods for calculating the behavior of nanobodies, taking into account such parameters of the state of particles as spatial coordinates and speed about sti, mass, characteristics of the composition, shape and structure of each nanoparticle.
Experimental nanochemistrydevelops in three directions. Within the framework of the first ultrasensitive spectral methods are being developed and used, yes Yu which give an opportunity to judge the structure of molecules, including tens and hundreds of atoms.Within the framework of the seconddirection, phenomena are studied at local (local) electric e physical, magnetic, or mechanical influences on nanobodies implemented with the help of nanoprobes and special manipulators.Under the thirdI define directions t macrokinetic characteristics of nanobodies collectives and distribution functions a notel by state parameters.
Applied Nanochemistry includes:
- Development of theoretical foundations for the use of nanosystems in engineering and nanotechnology about ology, methods for predicting the development of specific nanosystems under their conditions and with use, as well as the search for optimal methods of operation (technical but nochemistry).
- Creation of theoretical models of the behavior of nanosystems in the synthesis of nanomat e rials and the search for optimal conditions for their production (synthetic nanochemistry).
- The study of biological nanosystems and the creation of methods for using nanos and stems for medicinal purposes (medical nanochemistry).
- Development of theoretical models for the formation and migration of nanoparticles in the environment at living environment and methods of purification of natural waters or air from nanoparticles (ec about logical nanochemistry).
§five. Methods for obtaining nanoparticles
In principle, all methods for the synthesis of nanoparticles can be divided into two large groups:
Dispersion methods, or methods for obtaining nanoparticles by grinding a conventional macrosample
condensation methods, or methods of "growing" nanoparticles from individual atoms.
Dispersion methods
With dispersion methods, the initial bodies are ground to nanoparticles. This approach to obtaining nanoparticles is figuratively called by some scientists“top down approach” . This is the simplest of all ways to create nanoparticles, a kind of “meat”. about felling” for macrobodies. This method is widely used in the production of materials for microelectronics, it consists in reducing the size of objects to nanoscale within the capabilities of industrial equipment and the material used. And h It is possible to grind a substance into nanoparticles not only mechanically. The Russian company Advanced Powder Technologies obtains nanoparticles by exploding a metal thread with a powerful current pulse.
There are also more exotic ways to obtain nanoparticles. American scientists in 2003 collected microorganisms from the leaves of a fig tree Rhodococcus and placed them in a gold solution. The bacteria acted as a chemical with the former, collecting neat nanoparticles with a diameter of about 10 nm from silver ions. By building nanoparticles, the bacteria felt normal and continued to multiply.
Condensation methods
With condensation methods (“bottom up approach”) nanoparticles get n at themes of uniting individual atoms. The method lies in the fact that in controlled with conditions, ensembles of atoms and ions are formed. As a result, new objects are formed with new structures and, accordingly, with new properties that can be programmed by changing the conditions for the formation of ensembles. This one by d The move facilitates the solution of the problem of miniaturization of objects, brings closer to the solution of a number of problems of high-resolution lithography, the creation of new microprocessors, thin polymer films, and new semiconductors.
§6. Nanomaterials and prospects for their application
The concept of nanomaterials was first formulated in80s of the XX century by G. Gleiter, who introduced the term itself into scientific use " nanomaterial ". In addition to traditional nanomaterials (such as chemical elements and compounds, amorphous substances, metals and their alloys), they include nanosemiconductors, nanopolymers, a porous materials, nanopowders, numerous carbon nanostructures, a nobiomaterials, supramolecular structures and catalysts.
Factors that determine the unique properties of nanomaterials, are the dimensional, electronic and quantum effects of the nanoparticles that form them, as well as their very developed surface. Numerous studies have shown that the b significant and technically interesting changes in the physico-mechanical properties of nanomaterials (strength, hardness, etc.) occur in the particle size range from several a numbers up to 100 nm. At present, many nanomaterials based on nitrides and borides with a crystallite size of about 12 nm and less have already been obtained.
Due to the specific properties of the nanoparticles underlying them, such mats e rials are often superior to "ordinary" ones in many ways. For example, the strength of l Nanotechnology-derived steel is 1.5-3 times stronger than conventional steel, 50-70 times more hard, and 10-12 times more resistant to corrosion.
Applications of nanomaterials:
- elements of nanoelectronics and nanophotonics (semiconductor transistors and lasers; photodetectors; solar cells; various sensors)
- ultra-dense information recording devices
- telecommunications, information and computing technologies, supe r computers
- video equipment flat screens, monitors, video projectors
- molecular electronic devices, including switches and electronic circuits at the molecular level
- fuel cells and energy storage devices
- micro- and nanomechanics devices, including molecular motors and nanomotors, nanorobots
- nanochemistry and catalysis, including combustion control, coating, electrical to trochemistry and pharmaceuticals
- aviation, space and defense applications I environment
- targeted drug and protein delivery, biopolymers and biological tissue healing, clinical and medical diagnostics, creation of artificial muscles at fishing, bones, implantation of living organs
- biomechanics, genomics, bioinformatics, bioinstrumentation
- registration and identification of carcinogenic tissues, pathogens and biologically harmful agents; safety in agriculture and food production.
Omsk region is ready to develop nanotechnologies
The development of nanotechnologies is one of the priority areas for the development of science, technology and engineering in the Omsk region.
Thus, in the Omsk branch of the Institute of Semiconductor Physics of the Siberian Branch of the Russian Academy h development of nanoelectronics, and at the Institute of Problems of Hydrocarbon Processing of the Siberian Branch of the Russian Academy of Sciences, work is underway to obtain nanoporous carbon carriers and catalysts.
Sources of information:
- http://www.rambler.ru/cgi-bin/news
- http://www.rambler.ru/news
- ht tp : // Nanometer.ru
- http://www.nanonewsnet.ru/
67KB Lesson equipment: Presentation The beginning of the Great Patriotic War, where a map of the initial period of the war is used; fragments of documentaries about the war; a scheme on the readiness of Germany and the USSR for war; an exhibition of books dedicated to the Great Patriotic War ...
For the concept of nanotechnology, perhaps, there is no exhaustive definition, but by analogy with the existing microtechnologies, it follows that nanotechnologies are technologies that operate on values of the order of a nanometer. Therefore, the transition from "micro" to "nano" is a qualitative transition from the manipulation of matter to the manipulation of individual atoms. When it comes to the development of nanotechnologies, there are three areas in mind: the manufacture of electronic circuits (including volumetric ones) with active elements comparable in size to those of molecules and atoms; development and manufacture of nanomachines; manipulation of individual atoms and molecules and the assembly of macroobjects from them. Developments in these areas have been going on for a long time. In 1981, a tunneling microscope was created that allows the transfer of individual atoms. The tunnel effect is a quantum phenomenon of penetration of a microparticle from one classically accessible area of motion to another, separated from the first by a potential barrier. The basis of the invented microscope is a very sharp needle sliding over the surface under study with a gap of less than one nanometer. In this case, electrons from the tip of the needle tunnel through this gap into the substrate.
However, in addition to studying the surface, the creation of a new type of microscope opened up a fundamentally new way for the formation of nanometer-sized elements. Unique results were obtained on the movement of atoms, their removal and deposition at a given point, as well as local stimulation of chemical processes. Since then, the technology has been greatly improved. Today, these achievements are used in everyday life: the production of any laser discs, and even more so, the production of DVDs is impossible without the use of nanotechnical control methods.
Nanochemistry is the synthesis of nanodispersed substances and materials, the regulation of chemical transformations of nanometer-sized bodies, the prevention of chemical degradation of nanostructures, methods of treating diseases using nanocrystals.
The following are the areas of research in nanochemistry:
- - development of methods for assembling large molecules from atoms using nanomanipulators;
- - study of intramolecular rearrangements of atoms under mechanical, electrical and magnetic influences. Synthesis of nanostructures in supercritical fluid flows; development of methods for directed assembly with the formation of fractal, wireframe, tubular and columnar nanostructures.
- - development of the theory of physical and chemical evolution of ultrafine substances and nanostructures; creation of ways to prevent chemical degradation of nanostructures.
- - obtaining new nanocatalysts for the chemical and petrochemical industries; study of the mechanism of catalytic reactions on nanocrystals.
- - study of nanocrystallization mechanisms in porous media in acoustic fields; synthesis of nanostructures in biological tissues; development of methods for treating diseases by forming nanostructures in tissues with pathology.
- - study of the phenomenon of self-organization in groups of nanocrystals; search for new ways to prolong the stabilization of nanostructures by chemical modifiers.
- - The expected result will be a functional range of machines that provides:
- - methodology for studying intramolecular rearrangements under local effects on molecules.
- - new catalysts for the chemical industry and laboratory practice;
- - oxide-rare-earth and vanadium nanocatalysts with a wide spectrum of action.
- - methodology for preventing chemical degradation of technical nanostructures;
- - Methods for predicting chemical degradation.
- - nanodrugs for therapy and surgery, preparations based on hydroxyapatite for dentistry;
- - a method for the treatment of oncological diseases by carrying out intratumoral nanocrystallization and applying an acoustic field.
- - methods for creating nanostructures by directed aggregation of nanocrystals;
- - methods for regulating the spatial organization of nanostructures.
- - new chemical sensors with ultrafine active phase; methods for increasing the sensitivity of sensors by chemical modification.
Nanochemistry is a science that studies the properties of various nanostructures, as well as the development of new ways to obtain, study and modify them.
One of the priority tasks of nanochemistry is to establish a relationship between the size of a nanoparticle and its properties.
Nanochemistry Research Objects are bodies with such a mass that their equivalent size (the diameter of a sphere, the volume of which is equal to the volume of the body) remains within the nanointerval (0.1 - 100 nm)
Due to the location of the nanoworld on the borders of classical physics and quantum mechanics, its objects can no longer be considered as absolutely identical and statistically indistinguishable. All of them are individual, and one nanoparticle differs from another nanoparticle in composition, structure and many other parameters.
Nanochemistry is in the stage of rapid development, therefore, with its
The study constantly raises questions related to concepts and terms.
Clear distinctions between the terms “cluster”, “nanoparticle” and “quantum
dot” has not yet been formulated. The term "cluster" is more commonly used for
larger aggregates of atoms and is common to describe the properties
metals and carbon. Under the term "quantum dot" is usually
particles of semiconductors and islands are meant, where quantum
the limitations of charge carriers or excitons affect their properties.
Theoretical nanochemistry develops methods for calculating the behavior of nanobodies, taking into account such parameters of the state of particles as spatial coordinates and velocities, mass, characteristics of the composition, shape and structure of each nanoparticle.
Experimental nanochemistry develops in three directions.
1. Within first supersensitive spectral methods are being developed and used, which make it possible to judge the structure of molecules, including tens and hundreds of atoms.
2. Second direction explores phenomena under local (local) electrical, magnetic or mechanical effects on nanobodies, implemented with the help of nanoprobes and special manipulators. In this case, the goal is to study the interaction of individual gas molecules with nanobodies and nanobodies with each other, to reveal the possibility of intramolecular rearrangements without destruction of molecules and with their decay. This direction is also interested in the possibility of "atomic assembly" of a nanobody of the desired habitus(appearance) when atoms move over the surface of the substrate (the base material, the surface of which is subjected to various types of processing, resulting in the formation of layers with new properties or the growth of a film of another material).
3. Within third directions determine the macrokinetic characteristics of nanobodies collectives and their distribution functions according to state parameters.
Applied Nanochemistry includes:
§ development of theoretical foundations for the use of nanosystems in engineering and nanotechnology, methods for predicting the development of specific nanosystems in the conditions of their use, as well as the search for optimal methods of operation ( technical nanochemistry);
§ creation of theoretical models of the behavior of nanosystems in the synthesis of nanomaterials and the search for optimal conditions for their production ( synthetic nanochemistry);
§ study of biological nanosystems and creation of methods for using nanosystems for medicinal purposes ( medical nanochemistry);
§ development of theoretical models for the formation and migration of nanoparticles in the environment and methods for cleaning natural waters or air from nanoparticles ( ecological nanochemistry).
Medicine and healthcare. There is evidence that the use
nanodevices and nanostructured surfaces can increase the
efficiency of analysis in such a labor-intensive area of biology as deciphering
genetic code. Development of methods for determining individual
genetic traits has led to a revolution in the diagnosis and treatment
diseases. In addition to optimizing drug prescribing,
Nanotechnology has enabled the development of new methods of drug delivery to
diseased organs, as well as significantly increase the degree of their therapeutic
impact. Achievements in nanotechnology are used in research on
cell biology and pathology. Development of new analytical methods,
suitable for work at the nanometer scale, significantly increased
efficiency of studies of chemical and mechanical properties of cells
(including fission and movement), and also allowed to measure the characteristics
individual molecules. These new techniques have become a significant addition
methods related to the study of the functioning of living organisms.
In addition, the controlled creation of nanostructures leads to the creation of new
biocompatible materials with enhanced characteristics.
Molecular components of biological systems (proteins, nucleic10
acids, lipids, carbohydrates and their biological counterparts) are examples
materials whose structure and properties are determined at the nanoscale. Many
natural nanostructures and nanosystems are formed using
biological self-assembly methods. artificial inorganic and
organic nanomaterials can be introduced into cells, used for
diagnostics (for example, by creating visualized quantum
"dots") and be used as their active components.
Increasing the amount of memory and computer speed with the help of
nanotechnology has made it possible to proceed to the modeling of macromolecular
grids in a real environment. Such calculations are extremely important for
development of biocompatible transplants and new types of drugs.
Let us list some promising applications of nanotechnologies in
biology:
Fast and efficient deciphering of genetic codes that
is of interest for diagnosis and treatment.
Efficient and cheaper medical care with
using remote control and devices that work
inside living organisms
New methods of administering and distributing drugs in the body, which had
would be of great importance to improve the effectiveness of treatment (for example,
delivering drugs to specific locations in the body
Development of more resistant and not rejected by the body artificial
tissues and organs
Development of sensory systems that could signal
the occurrence of diseases within the body, which would allow doctors
deal not so much with treatment as with diagnostics and
disease prevention
Objects of supramolecular chemistry
The term "supramolecular chemistry" was first introduced in 1978.
Nobel laureate French chemist Jean-Marie Lehn and
defined as "the chemistry that describes complex formations that are
the result of the association of two (or more) chemical species bonded together
intermolecular forces. The prefix "supra" corresponds to the Russian
prefix "above".
Supramolecular (supramolecular) chemistry (Supramolecular
chemistry) is an interdisciplinary field of science, including chemical,
the physical and biological aspects of consideration are more complex than
molecules, chemical systems connected into a single whole through
intermolecular (non-covalent) interactions.
The objects of supramolecular chemistry are supramolecular
ensembles built spontaneously from complementary, i.e., having
geometric and chemical correspondence of fragments, like
spontaneous assembly of the most complex spatial structures in a living
cell. One of the fundamental problems of modern chemistry is
directed design of such systems, creation of molecular
"building blocks" of highly ordered supramolecular compounds
with the given structure and properties. Supramolecular formations
characterized by the spatial arrangement of their components, their
architecture, "suprastructure", as well as types of intermolecular
interactions that hold components together. Generally
intermolecular interactions are weaker than covalent bonds, so that
supramolecular associates are less thermodynamically stable, more
labile kinetically and more flexible dynamically than molecules.
Distance educational courses are a modern form of effective additional education and advanced training in the field of training specialists for the development of promising technologies for obtaining functional materials and nanomaterials. This is one of the most promising forms of modern education developing all over the world. This form of obtaining knowledge in such an interdisciplinary field as nanomaterials and nanotechnologies is especially relevant. The advantages of distance courses are their availability, flexibility in building educational routes, improving the efficiency and efficiency of the process of interaction with students, cost-effectiveness compared to full-time, which, nevertheless, can be harmoniously combined with distance learning. In the field of fundamental principles of nanochemistry and nanomaterials, video materials of the Scientific and Educational Center of Moscow State University on Nanotechnologies have been prepared:
- . Basic concepts and definitions of sciences about nanosystems and nanotechnologies. The history of the emergence of nanotechnology and the sciences of nanosystems. Interdisciplinarity and multidisciplinarity. Examples of nanoobjects and nanosystems, their features and technological applications. Objects and methods of nanotechnologies. Principles and prospects for the development of nanotechnologies.
- . Basic principles for the formation of nanosystems. Physical and chemical methods. Processes for obtaining nano-objects "from top to bottom". Classical, "soft", microsphere, ion-beam (FIB), AFM - lithography and nanoindentation. Mechanoactivation and mechanosynthesis of nanoobjects. Processes for obtaining nano-objects "bottom-up". Nucleation processes in gaseous and condensed media. Heterogeneous nucleation, epitaxy and heteroepitaxy. Spinodal collapse. Synthesis of nanoobjects in amorphous (glassy) matrices. Chemical homogenization methods (coprecipitation, sol-gel method, cryochemical technology, aerosol pyrolysis, solvothermal treatment, supercritical drying). Classification of nanoparticles and nanoobjects. Techniques for obtaining and stabilizing nanoparticles. Aggregation and disaggregation of nanoparticles. Synthesis of nanomaterials in one and two-dimensional nanoreactors.
- . Statistical physics of nanosystems. Features of phase transitions in small systems. Types of intra- and intermolecular interactions. hydrophobicity and hydrophilicity. Self-assembly and self-organization. Micellization. Self-assembled monolayers. Langmuir-Blodgett films. Supramolecular organization of molecules. Molecular recognition. Polymer macromolecules, methods for their preparation. Self-organization in polymer systems. Microphase separation of block copolymers. Dendrimers, polymer brushes. Layered self-assembly of polyelectrolytes. supramolecular polymers.
- . Substance, phase, material. Hierarchical structure of materials. Nanomaterials and their classification. Inorganic and organic functional nanomaterials. Hybrid (organo-inorganic and inorganic-organic) materials. Biomineralization and bioceramics. Nanostructured 1D, 2D and 3D materials. mesoporous materials. Molecular sieves. Nanocomposites and their synergistic properties. Structural nanomaterials.
- . Catalysis and nanotechnology. Basic principles and concepts in heterogeneous catalysis. Influence of preparation and activation conditions on the formation of the active surface of heterogeneous catalysts. Structure-sensitive and structure-insensitive reactions. Specificity of thermodynamic and kinetic properties of nanoparticles. Electrocatalysis. Catalysis on zeolites and molecular sieves. membrane catalysis.
- . Polymers for structural materials and for functional systems. "Smart" polymer systems capable of performing complex functions. Examples of "smart" systems (polymer fluids for oil production, smart windows, nanostructured membranes for fuel cells). Biopolymers as the most "smart" systems. biomimetic approach. Sequence design for optimizing the properties of "smart" polymers. Problems of molecular evolution of sequences in biopolymers.
- . The current state and problems of creating new materials for chemical current sources: solid oxide fuel cells (SOFC) and lithium batteries are considered. The key structural factors that affect the properties of various inorganic compounds, which determine the possibility of their use as electrode materials, are analyzed: complex perovskites in SOFCs and compounds of transition metals (complex oxides and phosphates) in lithium batteries. The main anode and cathode materials used in lithium batteries and recognized as promising are considered: their advantages and limitations, as well as the possibility of overcoming the limitations by a directed change in the atomic structure and microstructure of composite materials by nanostructuring in order to improve the characteristics of current sources.
Some issues are discussed in the following chapters of the books (Binom publishing house):
Illustrative materials on nanochemistry, self-assembly and nanostructured surfaces:
Scientific - popular "video books":
Selected Chapters of Nanochemistry and Functional Nanomaterials.
