Aluminum hydroxide is dispersed actual particle dispersion. Particle dispersion is referred to the separation of powder particles in a liquid medium and spread out evenly distributed throughout the liquid phase process, mainly including wetting, reunion, and stabilization of dispersed particle three-phase. Wetting refers to the mix powder ease to join system formed in the eddies, the adsorption on the surface of the powder, the process of air or other impurities being replaced by liquid. Solution together means by mechanical or ultrasonic methods, such as the larger particle size of aggregate dispersed into smaller particles. Stabilization means ensuring powder particles in a liquid to maintain long-term evenly dispersed.
1. mechanical dispersion method, etc
Mechanical dispersion is with the aid of the shear force and impacts force mechanical energy to make the nanoparticles fully dispersed in a medium one way. The mechanical dispersion method has grinding and ordinary ball mill, vibration ball mill, the colloid mill, grinding, mixing machinery, such as the air. This method is the common method of a decentralized superfine powder, but easy to introduce impurities, and may change the physical and chemical properties of the powder.
2. ultrasonic method
Ultrasonic dispersion is the handles of particle suspension directly put in a sound field, with proper frequency and power of ultrasonic processing, which is a kind of high strength dispersion method. The ultrasonic dispersing mechanism is cavitation effect, which can produce local high temperature and high pressure, and produce a great impact and micro jet, nanopowder under the action of its, the surface can be weakened, can effectively prevent the agglomeration of particles of dispersed adequately.
3. chemical dispersion method
Chemical dispersion or selecting one or more appropriate dispersants improve the dispersivity of the suspension, to improve its stability and rheological property. The commonly used dispersant are:
(1) small inorganic electrolytes or inorganic polymer molecular weight, such as sodium silicate, sodium aluminate, three poly potassium phosphate, etc. This kind of dispersant can occur dissociation and charged, adsorption in the surface of the Zibo Pengfeng Aluminum Hydroxide powders can improve the particle surface potential, make electrostatic repulsion increase, improve the stability of the slurry. Its mechanism is electrostatic repulsion stability.
(2) the surface-active agent, this kind of dispersant is consists of two parts, and a water-based pro-oil base, is the parent molecule, including long-chain fatty, CTAB, etc. Mainly space steric effect, hydrophilic radical adsorbed in the surface of the powder, hydrophobic chain.