Messi Biology said, nano magnesium hydroxide molecular formula Mg(OH)2, white microfine powder, non-toxic, tasteless, non-corrosive, relative density 2.36, refractive index 1.561, 350 ℃ began to decompose, 430 ℃ when the decomposition is rapid, 490 ℃ when all decomposition, soluble in strong acid solution and ammonium salt solution, insoluble in water. Compared with ordinary magnesium hydroxide products, nano magnesium hydroxide has special properties and applications, which are mainly manifested in.
I. Optical properties
When the grain size of metal material decreases to nanometer level, the color changes to black, and the grain size decreases. The light absorption ability of nanoparticles is proportional to their color. The quantum size effect of energy levels and the charge distribution on the grain surface also affect the process of light absorption. The conduction electron energy levels in the grains often coalesce into very narrow energy bands resulting in narrow absorption bands. Nonlinear optical effects become another aspect of the study of optical properties of nanomaterials.
II. Electromagnetic properties
The spacing of atoms of metallic materials is proportional to the variation of particle size. Therefore, when the metal grains are in the nanometer range, their density increases as the spacing becomes smaller. As a result, the average free range of free electrons in the metal decreases and the electrical conductivity decreases. In general, the magnetic structure of a magnetic material consists of many magnetic domains separated by domain walls, and the magnetization is achieved by the motion of the domain walls. In nanomaterials, when the grain size is smaller than a certain critical value, all grains show a single magnetic domain structure, and the coercivity becomes significantly larger. When the grain size of nanomaterials decreases, the magnetic ordering state of the core material changes radically. For example, materials that are ferromagnetic in the coarse crystalline state can be transformed into a superparamagnetic state when the grain size is smaller than a certain critical value.
Chemical catalytic properties
As the particle size of nanomaterials becomes smaller, the number of atoms on the surface will occupy a large proportion, the adsorption capacity will be strengthened and the chemical activity will increase. Therefore, under room temperature conditions, many metallic nanomaterials burn by violent oxidation reactions in the air. The inorganic nanomaterials exposed to the atmosphere will adsorb gases and form an adsorption layer. This property can be exploited to make gas-sensitive progenitors using nanomaterials for the detection of different gases. The catalytic properties of metallic nanomaterials are demonstrated by their ability to catalyze the breaking of H-H bonds, C-C bonds, C-O bonds, C-H bonds, etc. under suitable conditions. The main advantages of nanomaterials as catalysts are non-fine pores, no heterogeneous components, free choice of components, mild conditions and easy to use.
IV. Thermal properties
When the size of the constituent phase is small enough, various elastic and thermodynamic parameter changes in the confined atomic system lead to the change of the equilibrium phase. Hebei magnesium xi biological limited company through thermogravimetric experimental analysis can be seen, the average particle size of 40nm copper nanoparticles melting point from 1053 ℃ to 750 ℃. The melting point of nanomaterials is smaller than that of similar coarse crystalline materials, while the specific heat capacity is larger than that of coarse crystalline materials.