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Scientific papers on nanomaterials
Nano-materials refer to materials with at least one dimension in the nano-scale range (1- 100nm) or a three-dimensional space composed of them as basic units, which is approximately equivalent to the scale where 10 ~ 100 atoms are closely arranged together. The following is my scientific paper on nanomaterials, I hope you can get some insights from it!

Overview of nano-materials in scientific papers on nano-materials

The development, types, structural characteristics, application status and related application prospects of nano-materials are summarized, and the current research level and investment at home and abroad are compared and analyzed.

Nanometer, nanotechnology, nanomaterials, nanostructures

1 Introduction

Feynman, a famous scientist, used? Bottom-up approach? In order to meet the design requirements, it is suggested to be assembled from a single molecule or even an atom. He said,? At least in my opinion, the laws of physics do not rule out the possibility of making things atom by atom. ? And predict, When we control fine-sized objects, we will greatly expand the scope of obtaining physical properties. ? [ 1]

1974, scientist Donnie Gucci first used the term nanotechnology to describe precision machining. 1982, scientists invented the scanning tunneling microscope, an important tool for studying nano-materials, which enabled human beings to see atoms in the atmosphere and at room temperature for the first time, revealed a visible world of atoms and molecules for us, and played a positive role in promoting the development of nanotechnology. 1in July, 990, the first international nanotechnology conference was held in Baltimore, USA, marking the formal birth of nanotechnology. [2]

2 nanometer technology

Nanotechnology is a technology to accurately observe, identify and control the types, quantities and structural forms of substances at the level of a single atom and molecule. It is a multi-disciplinary high-tech, which studies the characteristics and interactions of substances on the nanometer scale and uses these characteristics to manufacture products with specific functions. Its ultimate goal is that human beings can directly manipulate individual atoms and molecules according to their own will to produce products with specific functions.

3 nano-materials

3. The concept of1nanomaterial

Nano-materials refer to materials with at least one dimension in the nano-scale range (1- 100nm) or a three-dimensional space composed of them as basic units, which is approximately equivalent to the scale where 10 ~ 100 atoms are closely arranged together. In terms of particle size, the particle size of fine particles that usually cause significant changes in physical and chemical properties is below 0. 1 micron, that is, below 100 nm. Therefore, particles with a particle size of 1 ~ 100 nm are called ultrafine materials and also nano-materials.

Nano-materials have certain uniqueness. When the size of matter is small enough, it is necessary to use quantum mechanics instead of traditional mechanics to describe its behavior. When the particle size of powder is reduced from 10 micron to 10 nanometer, although its particle size becomes 1000 times, it will be as large as 10 times when converted into volume, so there will be obvious differences between the two behaviors.

3.2 Classification of Nano-materials

Nano-materials can be roughly divided into four categories: nano-powder, nano-fiber, nano-film and nano-block. Among them, nano-powder has the longest development time and the most mature technology, which is the basis for the production of other three types of products.

(1) nano-powder

Nano-powder, also known as ultrafine powder or ultrafine powder, generally refers to powder or particles with a particle size below 100 nm, and is a solid particle material in an intermediate state between atoms, molecules and macroscopic objects. Can be used for: high-density magnetic recording materials; Absorb stealth materials; Magnetic fluid material; Radiation protection materials; Monocrystalline silicon and polishing materials for precision optical devices: microchip heat-conducting substrate and wiring materials; Microelectronic packaging materials; Photoelectric materials; Advanced battery electrode materials: solar battery materials; Efficient catalyst; Efficient combustion improver; Sensitive element; High toughness ceramic materials (ceramics that are not easy to break, used in ceramic engines, etc. ); Human body repair materials; Anticancer preparations, etc.

(2) Nanofibers

Nanofibers are linear materials with nanometer diameter and long length. Can be used for: microfilament, microfiber (an important part of quantum computer and photonic computer in the future) materials; New laser or LED materials, etc. Electrospinning is a simple method to prepare inorganic nanofibers at present.

(3) Nanofilms

Nano-membranes are divided into granular membranes and dense membranes. Particle film is a thin film with nano-particles stuck together, with a very fine gap in the middle. Dense film refers to the thin film with dense film layer but nanometer grain size. Can be used for: gas catalysis (such as automobile exhaust treatment) materials; Filter material; High density magnetic recording materials; Photosensitive material; Flat panel display materials; Superconducting materials, etc.

(4) Nanoblocks

Nano-block is a nano-particle material obtained by high-pressure molding of nano-powder or controlling crystallization of metal liquid. The main uses are: ultra-high strength materials; Intelligent metal materials, etc.

Application of 4 nano-materials

Nano-materials are composed of tiny units of molecular size or even atomic size. Because of this, nano-materials have some special physical or chemical properties different from other materials composed of the same chemical elements, such as their mechanical properties, electrical properties, magnetic properties [8] and thermal properties, etc., which have been applied to various scientific and technological fields and developed rapidly.

Prospect of 5 nanometer materials

Nanoscience is a new science which combines basic science and applied science, including nanoelectronics, nanomaterials and nanobiology. The application of nano-materials involves various fields, and 2 1 century will be the era of nano-technology. The birth of nanotechnology will have a far-reaching impact on human society, and it is possible to fundamentally solve many problems faced by mankind, especially major issues such as energy, human health and environmental protection.

At the beginning of the 20th century, the main task of 265438+ was to design various new materials and devices according to the novel physical and chemical characteristics of nanomaterials. At present, there are gratifying signs to transform traditional products through nano-material science and technology, increase their high-tech content and develop new products with nano-structure, which has the foundation to form new economic growth points in 2 1 century. Nano-materials will become a shining star in the field of materials science and play a decisive role in the fields of new materials, energy and information. With the continuous development of its preparation and modification technology, nano-materials will be widely used in many fields such as fine chemical industry and pharmaceutical production.

6 concluding remarks

Nano-materials play an important role in the development of high technology in 2 1 century. Nano-materials have become the focus of research all over the world because of their impeccable advantages. Its application has penetrated into all fields of human life and production, and promoted the improvement of many traditional industries. The governments of the developed countries in the world are planning the nanotechnology research plan for the next 10 ~ 15 years. China's research on nano-materials has also achieved world-renowned cutting-edge scientific and technological achievements. The development of nanotechnology and the application of nanomaterials have promoted the development of the whole human society and brought huge business opportunities to the market.

refer to

[1] Sun Hongqing. Science and Technology World-Planning and Market Exploration [M], 200 1/05

Xiao Jianzhong. Introduction to Materials Science [M]. Beijing: China electric power press, 200 1, 43 ~ 50.

Cherish Wu, Xie Changsheng. Progress and Prospect of Surface Research of Powder Nanomaterials [J]. Material Guide.2000, 14 (10): 43 ~ 46.

Nanomaterials and their applications

The classification and basic functions of nano-materials are briefly introduced, and the special properties of nano-materials are explained. The photoelectric conversion, hot spot conversion, supercapacitor and battery electrode nanomaterials in new energy nanomaterials are analyzed. Photocatalysis, adsorption and tail gas treatment in nano-materials for environmental purification: In this paper, nano-ceramic materials, nano-carbon materials, nano-polymer materials and nano-composite materials in nano-biomedical materials are described in detail.

Keywords: application of nano-materials performance

Nanometer is the unit of length, 1nm= 10ˉ9m. Nano-materials refer to materials with nanometer modulation characteristics in structure, and nanometer generally refers to 1 ~ 100 nm. When the structure of a material enters the nano-scale feature range, one or some of its properties will change obviously. Nano-scale and specific changes in characteristics are two basic characteristics that nano-materials must have at the same time.

Nano-materials can be divided into nano-metal materials, nano-nonmetal materials, nano-polymer materials and nano-composite materials according to materials. Nano-nonmetallic materials can be subdivided into nano-ceramic materials, nano-oxide materials and other non-metallic nano-materials.

Nanoparticles suspended in fluid can greatly improve the thermal conductivity and heat transfer effect of fluid. For example, adding 5% nano-copper particles to water can increase the thermal conductivity by about 65438 0.5 times, which is of great significance to improve the thermal efficiency of metallurgical industry. Nano-particles can show different optical characteristics from homogeneous bulk objects, such as broadband, strong absorption, blue shift phenomenon and new luminescence phenomenon, so they can be applied to luminescent and reflective materials, optical communication, optical storage, optical openings, filter materials, photoconductor luminescent materials, optical nonlinear elements, wave-absorbing stealth materials and infrared sensors.

Nanoparticles also show many uniqueness in electrical properties. For example, nano-metal particles are insulated at low temperature, and nano-lead titanate, barium titanate and other particles change from typical ferroelectric to paraelectric. Nanoparticles can be used to make conductive pastes, insulating pastes, electrodes, superconductors, quantum devices, electrostatic shielding materials, piezoresistive and nonlinear resistors, thermoelectric and dielectric materials, etc. Nanoparticles have small particle size and large surface atomic ratio. Surface atoms have residual chemical bond force, showing strong adsorption capacity and high surface chemical reaction activity. The newly prepared metal particles will undergo violent oxidation reaction or luminous combustion (except precious metals) when they contact with air.

Nano-materials are also widely used in the field of environmental protection, with outstanding characteristics such as low energy consumption, simple operation, mild reaction conditions and reduction of secondary pollution. Nanomaterials are also widely used in biological characteristics. It is easy to separate a very small number of fetal cells from blood samples with nanoparticles. This method is simple and low cost, and can accurately judge whether there is genetic defect in fetal cells. Artificial nanomaterials have achieved rapid development in recent years because of their unique properties that can meet the diverse needs of human development. At present, more and more artificial nano-materials are put on the market, which has brought great changes and progress to people's lives.

Researchers from UCLA and Tianjin University in China cooperated to weave carbon nanotubes with good conductivity and high-capacity vanadium oxide into porous fiber composites, and applied the composites to the electrodes of supercapacitors to obtain new supercapacitors with high energy density and high cycle stability. This kind of supercapacitor is asymmetric, including composite anode and traditional cathode, as well as organic electrolyte. The thickness of the electrode film is much higher than that reported before, which can reach 100 micron, so that higher energy density can be obtained. Because its preparation process is similar to traditional lithium-ion batteries and capacitors, researchers believe that this new capacitor can be easily put into mass production. At the same time, they also think that the research results show their colleagues the application prospect of nanocomposites in high-energy and high-power electronic devices.

Through the application of advanced carbon materials, the advantages of artificial graphite and natural graphite as anode materials of lithium ion batteries are integrated, and their respective disadvantages are overcome. It is a new generation of carbon lithium storage material that meets the performance requirements of advanced lithium-ion batteries. It has the following advantages: good microstructure stability, suitable for high current charge and discharge; The compatibility of apparent characters is good, which is suitable for forming stable SEI film; The particle morphology and particle size distribution have strong adaptability and are suitable for different processing requirements. It is suitable for the requirements of advanced lithium ion batteries (liquid and polymer) for the following properties: higher specific energy (volume ratio, weight ratio); Higher specific power; Longer cycle life; The use cost is lower.

New materials such as nano-TiO2 _ 2 foam nickel metal filter screen, formaldehyde, ammonia gas and TVOC adsorption modified activated carbon were adopted, and the traditional centrifugal fan structure was replaced by inertial fan, which improved the performance of the air purifier. Characteristics of photocatalytic nickel foam metal filter screen: Nickel metal mesh is a metal filter screen with three-dimensional mesh structure made of metal nickel through special process. It has the following advantages: the gap is enlarged, generally greater than 96%; Good permeability and low fluid resistance; Its actual area is many times larger than its apparent area. Nickel metal mesh is a special process to embed nano-TiO2 _ 2 on nickel foam metal mesh, thus combining the functions of sterilization, deodorization and decomposition of organic matter of photocatalytic materials with the ultra-stability of nickel. Effectively solve the shortcomings of other photocatalytic materials, such as small effective light receiving area, small contact area between fluid and photocatalytic materials, large gas resistance and short service life caused by strong oxidation of photocatalytic materials under photocatalytic action. Modification process of activated carbon and improvement of its performance: Activated carbon is a porous carbonaceous substance with highly developed pore structure, and it is an excellent adsorbent for odor in the air.

Nano-TiO2 _ 2 _ 2 has a huge specific surface area, can fully contact with the organic matter in wastewater, and can adsorb the organic matter on its surface to the maximum extent, so it has a stronger ultraviolet absorption capacity, so it has a stronger photocatalytic degradation capacity and can quickly decompose the organic matter on its surface. In addition, it is also widely used in automobile exhaust catalysis and air purification.

Due to the influence of pores and defects, conventional ceramics are fragile at low temperature. Its elastic modulus is much higher than that of human bone, its mechanical compatibility is poor, it is prone to fracture, and its strength and toughness can not meet the higher clinical requirements, which limits its application to some extent. However, due to the small grain size of nano-ceramics, the size of pores or defects in the material is greatly reduced, and the material is not prone to transgranular fracture, which is conducive to improving the fracture toughness of the material; However, grain refinement greatly increases the number of grain boundaries, which contributes to the slip between grains and makes nano-ceramics show unique superplasticity. Many nano-ceramics can be plastically deformed at room temperature or lower. The superplasticity of nano-ceramics is its most remarkable achievement. Traditional oxide ceramics is an important biomedical material, which has been widely used in clinic, mainly used to manufacture artificial bones, artificial foot joints, elbow joints, shoulder joints, bone screws, artificial teeth, dental implants, otoauditory bone restorations and so on.

Carbon nanomaterials composed of carbon elements are collectively referred to as nano-carbon materials. Nano-carbon materials mainly include nano-carbon fibers, carbon nanotubes and diamond-like carbon. Besides the low density, high specific modulus, specific strength and high conductivity of micron carbon fiber, nano carbon fiber also has the characteristics of few defects, large specific surface area and compact structure. These extraordinary characteristics and good biocompatibility make it have a wide application prospect in the medical field, including significantly improving the strength, hardness and toughness of artificial organs, artificial bones, artificial teeth and artificial tendons. In addition, using the high-efficiency adsorption characteristics of nano-carbon materials, it can also be used in blood purification systems to remove some viruses or components.

At present, the application of nano-polymer materials has involved many aspects such as immunoassay, drug controlled release carrier, interventional diagnosis and treatment. Immunoassay, as a routine analytical method, plays an important role in the quantitative analysis of protein, antigen, antibody and even the whole cell. On a specific carrier, the immunoaffinity molecular marker corresponding to the analyte is fixed by valence bond binding, the solution containing the analyte is incubated with the carrier, and the amount of free carrier is detected by microscope, so that the analyte can be accurately and quantitatively analyzed. The selection of carrier materials is very important in immunoassay. Nano-polymer particles, especially those with hydrophilic surfaces, have little adsorption capacity for nonspecific protein, so they are widely used as new labeling carriers.

In recent years, tissue engineering has become a brand-new research field, attracting the attention of many researchers. In the process of engineering culture of tissues and organs, scaffold materials for cell planting and growth are a key factor, and whether the planted cells can maintain their activity and proliferation ability is an important condition for the application of scaffold materials. It is reported that nano-structured composites can be made by adding a certain proportion of chitin to collagen. Compared with the previous collagen scaffold, its mechanical strength is enhanced and its pore size is enlarged, which shows that this nano-structured composite material has great advantages and application potential in mechanics and biology as a three-dimensional scaffold for cell growth. In the research of hard tissue repair and replacement, nanocomposites gradually show their excellent properties. Fibrous scaffolds similar to extracellular matrix can be obtained by self-assembly of peptide molecules and amphiphilic compounds. This kind of nanofiber can guide the mineralization of hydroxyapatite and form nano-structured composite materials. It is found that the microstructure of the nanocomposite is consistent with the arrangement structure of collagen/hydroxyapatite particles in natural bone.

References:

Chen Fei. On the Application of Nano-materials [J]. Management and Technology of Small and Medium-sized Enterprises (Next Issue) .2009 (03)

[2] Zhang Guifang. Application and Development Prospect of Nanomaterials [J]. Heilongjiang Science and Technology Information.2009 (16)