Properties of nano-calcium
Time: 2019-12-10
1, the special properties of nano-calcium
Nano-calcium has a significant effect on the migration, transformation and enrichment of pollutants in the surface environment due to its large specific surface area, high reactivity and strong migration ability. The effect of particle size on the homogeneity of mineral multiimage transformation is one of the important manifestations of the special mineralogical properties of nano-calcium. The surface energy of particles increases significantly with the decrease of particle size. When the particle size is reduced to the nanometer size range, the surface energy increases enough to change the influence law accordingly.
Because of the characteristics of small particle size and large surface energy, nano-sized calcium particles are more inclined to agglomerate in natural water than large-sized particles, and can exist in the form of agglomerates for a long time. Nano-calcium agglomeration behavior can not only change the number of active sites on the surface of the reaction, but also cause the agglomeration of nano-calcium particles to form larger particles under certain conditions.
2. Inorganic interface reaction of nano-calcium and its environmental effect
One of the most concerned environmental properties of nano-calcium is the adsorption of particles on pollutants in the environment. The particles can adsorb heavy metal ions in the environment by electrostatic force, ion exchange and surface complexation. With the decrease of particle size, not only the specific surface area of the particles increases, but also the surface charge density, the number of surface unsaturated coordination atoms, the surface defect density and the surface energy of the mineral particles increase, which makes the adsorption capacity and affinity of the particles to heavy metal ions increase. A large number of experiments have proved that the ability of nano-mineral particles to adsorb heavy metals is much greater than that of the corresponding large-size mineral particles under the condition of equal mass concentration.
Some weathering, microbial respiration and degradation of pollutants in the surface environment all involve the interfacial electron transfer process of natural minerals, which belongs to oxidation-reduction in essence.
Catalytic reactions occurring on mineral surfaces are common in the natural environment and significantly affect a variety of geochemical processes. When the particle size is reduced, a large proportion of atoms are located on the surface of the particle, and the electrical properties will change accordingly, so that the nano-calcium exhibits different catalytic activity from the large-sized minerals.