Application of laser particle size analyzer in particle size detection of nanomaterials

1. Nanomaterials

    Nanostructured materials are referred to as nanomaterials. Broadly speaking, they refer to ultra-fine particle materials with at least one dimension in the nanoscale range in three-dimensional space. According to the definition adopted by the European Commission on October 18, 2011, a nanomaterial is a powdery or agglomerated natural or artificial material composed of basic particles with one or more three-dimensional dimensions ranging from 1 nanometer to 100 nanometers. between nanometers, and the total number of this basic particle accounts for more than 50% of the total number of particles in the entire material. Nanomaterials have certain uniqueness. When the scale of matter is small to a certain extent, quantum mechanics must be used instead of traditional mechanics to describe its behavior. When the size of powder particles is reduced from 10 microns to 10 nanometers, its particle size Although the change is 1000 times, when converted into volume, it will be 10 times the 9th power, so there will be obvious differences in the behavior of the two.

Nanotechnology and nanomaterials are high-tech technologies that are highly valued in the world today, and they are also the basis of all high-tech technologies. Although there are still many technical issues that need to be further studied, such as nanoparticle size, distribution and morphology control; control and dispersion of agglomerates; surface properties and surface modification of nanoparticles; basic theory of nanomaterials, etc., it has already Shows strong vitality. A research report published by the European Commission in 1995 predicted that the development of nanotechnology will become the world's second largest manufacturing industry after chip manufacturing in the next 10 years. Breakthroughs in the market are likely to be in information, microelectronics, medicine, environment and other fields. Our country has abundant raw materials and a broad market for the development of nanomaterials, and the application of nanomaterials will have a bright future.

2. Application and current situation of nanomaterials

   Applications of nanomaterials: (1) Nanotechnology in the information industry: ① Network communication, broadband network communication, nanostructured devices, chip technology and high-definition digital display technology. ② Optoelectronic devices, molecular electronic devices, giant magnetic electronic devices. ③ Our country’s research level does not lag behind in terms of key nanodevices for network communications, such as lasers, filters, resonators, microcapacitors, microelectrodes, etc. in network communications, and they are available in Anhui Province. ④Varistors, nonlinear resistors, etc., can be modified by adding zinc oxide nanomaterials. (2) Nanotechnology in the environmental industry: Nanotechnology is an irreplaceable technology for the degradation of 20 nanometer pollutants in the air and 200 nanometer pollutants in water. To purify the environment, nanotechnology must be used. We have now successfully prepared a device that can degrade formaldehyde, nitrogen oxides, and carbon monoxide, which can reduce harmful gases greater than 10ppm in the air to 0.1ppm. This device has entered the practical production stage; using porous pellet combination photocatalytic nanomaterials,It has been successfully used to degrade organic matter in sewage, and has a good degradation effect on organic pollutants such as phenol that are difficult to degrade with other traditional technologies. In recent years, many companies have been committed to transplanting nanotechnology such as photocatalysis into the water treatment industry to improve water quality, and have achieved results; (3) Nanotechnology in energy and environmental protection: In terms of rational utilization of traditional energy, it is now mainly They are purifiers and combustion accelerants, which can make coal fully burn, self-circulate during combustion, reduce sulfur emissions, and no longer require auxiliary devices. In addition, there are already additives that use nanometers to improve gasoline and diesel. In fact, they are a kind of liquid small molecule combustible cluster material that can support combustion and purify. Nowadays, the world is mainly developing energy conversion materials, and my country is also doing it. It includes converting solar energy into electrical energy, thermal energy into electrical energy, chemical energy into electrical energy, etc. (4) Nanobiomedicine: Currently, the international pharmaceutical industry is facing a new decision, which is to develop the pharmaceutical industry at the nanoscale. Nanobiomedicine is to extract necessary substances from animals and plants and then combine them at the nanoscale to maximize the efficacy. This is exactly the idea of my country's traditional Chinese medicine. After extracting the essence, a very small backbone, such as sugar and starch that can be absorbed by the human body, is used to make it highly efficient and sustained release of targeted drugs.

The improvement of traditional medicines can be taken to the next level by using nanotechnology. (5) Nano new materials: According to US estimates, by the 21st century, 40% of steel and metal materials in automobiles will be replaced by lightweight and high-strength materials. This can save 40% of gasoline, reduce CO2, and reduce emissions by 40%. That’s it. One item can create social benefits of US$100 billion for the United States every year. In addition, there are various functional materials. Glass has good transparency but is heavy. We use nanometers to improve it and make it lighter. This material not only has mechanical properties, but also has other functions, including light discoloration and light storage. Reflect various ultraviolet, infrared, light absorption, storage and other functions. (6) Nanotechnology transforms traditional industries: For China, currently is the best opportunity for nanotechnology to enter traditional industries and combine nanotechnology with technologies in various fields. The first is the home appliances, light industry, and electronics industries. Hefei Meiling Group has been developing nano-refrigerators since 1996. The foldable PVC magnetic refrigerator door seal is mold-free and uses antibacterial paint. The fruit bowl inside is made of nano-materials. The development of light industry, electronics and household appliances can drive the development of coatings, materials, electronics The development of industries such as original devices; followed by textiles. Man-made fibers are the development trend of the chemical fiber and textile industries.

Nanotechnology and nanomaterials are high-tech technologies that are highly valued in the world today, and they are also the basis of all high-tech technologies. Although there are still many technical issues that need to be further studied, such as nanoparticle size, distribution and morphology control; control and dispersion of agglomerates; surface properties and surface modification of nanoparticles; basic theory of nanomaterials, etc., it has already Shows strong vitality. A research report published by the European Commission in 1995 predicted that the development of nanotechnology will become the world's second largest manufacturing industry after chip manufacturing in the next 10 years. Breakthroughs in the market are likely to be in information, microelectronics, medicine, environment and other fields. Our country has abundant raw materials and a broad market for the development of nanomaterials, and the application of nanomaterials will have a bright future.

3. Nanomaterial particle size analysis

With the widespread application of nanomaterials in high-tech industries, national defense, medicine and other fields, particle measurement technology will develop in the direction of low measurement limits, wide measurement ranges, high measurement accuracy and precision, and good reproducibility. Therefore, the requirements for particle measurement technology are becoming higher and higher. Looking at various particle measurement methods and technologies, in order to adapt to the higher requirements of particle size analysis, particle size analysis methods such as light scattering method, measurement method based on particle Brownian motion and mass spectrometry will be more perfect and more widely used. In order to meet the needs of the development of nanotechnology, the particle size analysis method of nanomaterials has gradually become an important part of particle size analysis. At present, the methods suitable for particle size analysis of nanomaterials are mainly laser dynamic light scattering particle size analysis and photon correlation spectroscopy, which can measure the minimum particle size of 20nm and 1nm.