Do you understand the grinding and dispersing process of nano-sanding machines?
This paper selectsNano Sand GrinderMixed crushing method to prepare nano-composite inverter-resistant insulating materials, the advantage of this method is that the substrate itself has a large choice of space, can be selected to introduce a single or composite nanoparticle components, and the composition of nanoparticles and data steps, can control the shape and size of nanoparticles. The disadvantage is that the particle size of nanoparticles is small, larger than the appearance, the appearance can be higher, it is easy to form a larger particle size of the party body, so that the nano-components are difficult to play its common effect, and blending when it is necessary to ensure the uniform dispersion of particles, there are certain difficulties. In order to improve the function of composites, it is necessary to use the dispersion methods such as sanding to assist dispersion, and to use various appearance treatment and modification methods to preprocess nanoparticles before blending, in order to avoid base gathering and promote the softness between them and polymers and the dispersion in polymers.
Dispersion principle of particle using nano-sand Grinder:
The driving force to achieve powder condensation is van der Waals force in dry powder state, and in solution it should be attributed to Brownian motion and van der Waals force, as shown in Figure 3.1.
The dispersion of particles is the use of nano-sanding machine to separate its party body into a single particle, perhaps a few small particle meeting body evenly dispersed in liquid phase medium. Generally includes two processes, that is, the dispersion of the medium in the volume of the reduction and consistency of the process and the dispersion of the media in the space dispersion of the uniform process. In general, the uniform dispersion of particles in the medium is not difficult, the key in how to soak it abundant, this is a solid-gas interface disappeared, solid liquid interface composition of the process. The process can be analyzed from the thermodynamic point of view as follows: Taking the meeting body of nanoparticles as the unit, the free energy of the system caused by this process is changed to G=ΔSL-ΔSG under constant temperature constant pressure. Usually there are 0<><π so="" it="" is="" necessary="" for="" the="" particles="" to="" fully="" enter="" the="" medium="" that="" the="" particles="" have="" enough="" energy="" or="" external="" forces="" to="" do="" the="" homework="" to="" overcome="" the="" energy="" barrier="" "53"="" that="" the="" interface="" can="" cause.="" the="" size="" of="" the="" energy="" base="" is="" w="FP" "3δ="" (1cosθ)?/4r-r="" (2pp-p1)="">π>
Among them: the volume concentration of the fp-particles, the free energy of the δlg-gas-liquid interface, the wet angle of the θ-particles, the relative density of the pp-particles, the relative density of the pl-liquid, g-the gravitational acceleration. As can be seen from the formula, the size of the external force required for particles to enter the liquid depends on such elements as the wet angle of the particle and the liquid, the relative density of the particles and liquids, the volume fraction of the particles and the size of the particles. When the properties of particles and the properties of liquids remain unchanged, with the decrease of particle size and volume fraction, the work of external force required increases, and the difficulty of entering is added, while for different varieties of nanoparticles and organic matrix matching system, the better the humidity of the two, the greater the density of particles relative to the density of liquid, the more conducive to the entry
The appearance of particles can be modified to change the physical properties of particles, enhance the moisture between the dispersion medium.
The van der Waals potential energy between the two molecules can be expressed as:
In Formula X is the molecular distance, and lambda is the gravitational constant that touches the molecular polarization rate and the characteristic frequency.
When the Brownian movement brings particles to a very close distance, van der Waals's gravitational pull between the particles is mainly caused by the effects of its appearance between molecules, which can be expressed as:
The F=dфa/da=dфadx/dxda=6λdx/x7da type A is the particle outer distance, the DXDA is the item related to the particle shape, to the specific particle, the dxda is constant. It is clear that the inevitable x,f is only related to lambda, and lambda is a material characteristic, the material is different, then the lambda is different, that is, the change of f reflects the particles. This shows that the effect of nano-sanding machine on the preparation of titanium dioxide or other nanoparticle materials is insignificant.