⒈ nanomaterials: when the material to the nanometer scale, about 1-100 nanometers in this range of space, the performance of the material will undergo a sudden change, the emergence of special properties. This is different from the original composition of atoms, molecules, but also different from the macroscopic material composition of the special properties of the material, that is, nanomaterials. If only the scale reaches nanometer, and there is no special properties of the material, also can not be called nanomaterials. In the past, people only pay attention to atoms, molecules or cosmic space, often ignoring this intermediate field, which actually exists in large quantities in the natural world, but only previously did not recognize the performance of this scale range. The first real recognition of its performance and cited the concept of nanometer is the Japanese scientists, they used the evaporation method in the 1970s to prepare ultramicro ions, and through the study of its performance found that: an electrically conductive, thermally conductive copper, silver conductor into the nanoscale, it will lose the original nature of the performance of the conductivity of electricity is not conductive, nor is it thermally conductive. Magnetic materials is also the case, such as cobalt iron alloy, make it about 20-30 nanometer size, the magnetic domains into a single domain, its magnetic properties than the original 1000 times higher. the mid-80's, people formally named this type of material as nanomaterials.
Peake nanodynamics, mainly micro-mechanical and micro-motor, or always called micro electro-mechanical systems, used in micro sensors and actuators with transmission machinery, fiber-optic communication systems, special electronic equipment, medical and diagnostic instruments, and so on. Used in a new process similar to the design and manufacture of integrated electrical appliances. Characterized by very small parts, the depth of etching often requires tens to hundreds of microns, while the width error is very small. This process can also be used to make three-phase motors for ultra-fast centrifuges or gyroscopes, for example. In research there is also the corresponding detection of microdeformations and microfriction at the quasi-atomic scale, etc. Although they are not yet really into the nanoscale, but there is a great potential scientific value and economic value.
3 nanobiology and nanopharmacology, such as in the mica surface with nano-particle degree of colloidal gold fixed dna particles, in the silica surface of the fork-finger electrode to do the test of interactions between biomolecules, phospholipids and fatty acids bilayer planar biofilm, the fine structure of the dna and so on. With nanotechnology, self-assembly methods can also be used to put parts or components inside cells to make up new materials. New drugs, even micron particles of fine powder, about half of the insoluble in water; but if the particles for the nanometer scale (i.e., ultra-micro particles), can be dissolved in water.
Sung nanoelectronics, including nanoelectronic devices based on quantum effects, optical/electrical properties of nanostructures, characterization of nanoelectronic materials, and atom manipulation and atom assembly. Current trends in electronics require devices and systems to be smaller, faster, and colder,Smaller means faster response time. Colder means that the power consumption of individual devices should be small. But smaller is not without limits. Nanotechnology is the final frontier for builders, and its impact will be enormous.
In April 1998, the President's Science and Technology Advisor, Dr. Neal Lane, commented that if someone were to ask me which area of science and engineering would have a breakthrough impact on the future, I would say that the launching of the program, called the Grand Challenges in Nanotechnology Institute, would fund interdisciplinary research and education teams, including centers and networks for long-term goals. Some of the potential breakthroughs that could be realized include:
Compressing the entire Library of Congress into a piece of equipment the size of a sugar cube, which could be accomplished by increasing the storage capacity per unit of surface by a factor of 1,000 to expand the storage capacity of large storage electronics to the level of a few terabytes. Manufacturing materials and products from a small-to-large approach, i.e., making them from an atom, from a molecule. This method will save raw materials and reduce pollution. Producing materials that are 10 times stronger than steel and a fraction of its weight to make a variety of lighter, more fuel-efficient vehicles for land, water and air transportation. Increase the speed and efficiency of computers millions of times over with tiny transistors and memory chips, making today's Pentium? processors already seem very slow. Use of gene and drug delivery nanoscale mri controls to detect cancer cells or locate human tissues and organs to remove the tiniest pollutants in water and air, resulting in a cleaner environment and drinkable water. Increase solar cell energy efficiency by two times.
What is nanotechnology?
Nanoscience and technology is the study of the movement and change of atoms, molecules and other types of matter in the range of ten millionths of a meter (10-8) to billionths of a meter (10-9 m); at the same time, manipulation and processing of atoms and molecules in this range of scales is also known as nanotechnology.
Research in nanotechnology
Creating and preparing nanomaterials with excellent properties
Designing and preparing various nanodevices and devices
Detecting and analyzing the properties and phenomena in the nanoregion
What is nano?
Nano is a unit of measurement of size or dimension:
Kilometer (103 ) → meter → centimeter → millimeter → micrometer → nanometer (10-9)
Four times the size of an atom, one ten-thousandth of a hair
What problems are studied in nanotechnology?
Biological science and technology, information science and technology, and nanotechnology are the mainstream of scientific and technological development within the next century. The understanding of genes in bioscience and technology has given rise to genetically modified organisms (GMOs), which can cure stubborn diseases and create organisms that don't exist in nature; information science and technology has enabled people to know the world's events while sitting at home, and the Internet has almost changed people's lifestyles.
Nanoscience is the study of the movement and change of atoms, molecules and other types of matter in the range of ten millionths of a meter (10-8) to billionths of a meter (10-9 meters); at the same time, manipulation of atoms and molecules in this scale range and processing is also known as nanotechnology.
Reductionism: the motion of matter are reduced to the level of atoms and molecules. Atomic theory and quantum mechanics have had great success. Organic synthesis; molecular biology; genetically modified foods, cloned sheep; atomic spectroscopy and lasers; solid state electron theory and IC; geometric optics to fiber optic communications.
Great achievements in classical physics, chemistry, and mechanics in the macroscopic world: computers and networks, spaceships, airplanes, automobiles, robots, etc. have changed the way people live
Science and technology have epistemological blind spots or cracks in the edifice of human knowledge. On one side of the crack is the microcosmic world dominated by atoms and molecules, and on the other bank is the macrocosmic world of human activities. There is not a direct and simple connection between the two worlds; there is a transition zone - the nanoworld.
Example: molecular synthesis ≤1.5nm, → living body
Microelectronics at 0.2μm,
Microsurgery can only connect the large, small, microvascular
≤ PM10 and PM1.5 particles
In the 50s, the old Qian's "Physical Mechanics" was the One of the precursors to the attempt to connect the two worlds
The figure shows the tip of a scanning tunneling microscope
being used to carry and manipulate 48 atoms on the surface of copper, lining them up in a circular
shape. Certain electrons from the atoms on the circle
propagate outward, gradually decreasing in size while
interfering
with electrons traveling in-phase
to form interference waves.
Dozens of atoms and molecules, or thousands of atoms and molecules "combined" together, showing different properties from both individual atoms and molecules, as well as the properties of large objects. This "combination" is called "supramolecular" or "artificial molecules". "Supramolecular" properties, such as melting point, magnetism, capacitance, electrical conductivity, luminosity and dye, color and water solubility have significant changes. When the "supramolecule" continues to grow or aggregates in the usual way into large pieces of material, the peculiar properties will be lost again, like really some of the children who never grow up.
The recognition of new laws in systems consisting of a small number of electrons, atoms or molecules at the 10-nm scale and how to manipulate or combine and detect and apply them -- the main problems of nanoscience and technology.
New phenomena and laws within the transition zone between the microcosm and macrocosm of atoms and molecules
New principles and methods for detecting physical, chemical biological information within the length of nanometers
New concepts and theories: strong correlations, strong fields, fast processes, and quantum systems with few particles
Applications
New science or rehash of old theories?
Historic new science and technology
Western Han bronze mirrors and black-lacquered drums
Huizhou ink
Lacquerware
Catalyst materials
Photoreceptors and color film
Tires with kaolin particles
WHY? It's not clear
In the last decade, computers and materials design; Detection technologies STM, AFM, SNOM; IC and life sciences push; preparation technology development; theory development
High strength and toughness, self-healing, smart, renewable → new generation of nanomaterials
Why is small size so important?
Surface effects
Small-size effects
Quantum-limited-domain effects
Research goals and possible applications
Materials and preparations: lighter, stronger, and designable; long-life and low-maintenance; materials with specific properties or materials that do not naturally exist, constructed on a nanoscale level with new principles and structures; biomaterials and bionanomaterials; Diagnosis and repair of damage at the nanoscale during the destruction of materials;
Microelectronics and computer technology: the realization of chips with lines of 100 nm in 2010, and the goals of nanotechnology are: nanostructured microprocessors with a million-fold increase in efficiency; high-frequency network systems with a 10-fold increase in bandwidth; megabits of memory (a 1,000-fold increase); and integrated nano-sensor systems;
Medicine and Health
Rapid, efficient gene cluster sequencing and gene diagnostics and gene therapy technologies; new approaches to medication and drug 'missile' technologies; durable human-friendly artificial tissues and organs; sight-restoring and deaf-restoring devices; nanosensor systems for early diagnosis of disease
Space and Aeronautics
Low-energy, irradiation-resistant, high-performance computers; micro-spacecraft nano-testing, control and electronic devices; nanostructured coating materials resistant to thermal barriers and abrasion
Environment and Energy
Development of green energy and environmental treatment technologies to reduce pollution and restore damaged environments;
Nano-porous materials with a pore size of 1 nm as a carrier for catalysts; MCM-41 ordered nano-porous materials (pore sizes of 10-100 nm) used to remove dirt; nanoparticle-modified polymeric materials
Biotechnology and agriculture
Biologically active proteins, ribose, nucleic acids, etc. are prepared at the nanoscale according to predetermined sizes, symmetries and arrangements. Implantation of biomaterials in nanomaterials and devices produces integrated properties with biological and other functions. Bio-biomimetic chemicals and biodegradable materials, genetic improvement and treatment of plants and animals, gene chips for DNA determination, etc.