Agglomeration and distribution of nanoparticles
One can classify the agglomeration nanoparticles in two ways: soft or hard. Most of the soft agglomeration occurs due to electrostatic interactions between particles, as well as van der Waals forces. The weak force allows soft agglomeration to pass certain chemical tests.
Use of mechanical energy, or the law, to exterminate; The formation of hard-agglomeration.
Schematic diagram showing the aggregate of nanoparticles
The van der Waals effect or interaction between the groups is one of the ways to prevent nanoparticles from forming hard-block precipitates. It allows the primary particles not to agglomerate to create secondary particles. This causes the formation of hard-blocked precipitates with high densities. The anti-agglomeration mechanism is broken down into the following: (1) electrostatic stabilizement (DLVO theory);(2) steric stable; (3) electrostatic steric staining.
By adjusting pH to form an electric double, the electrostatic stabilization system, also known by the electric layer stabilization scheme, produces a surface charge. Repulsive force between two layers of electric is able to reduce the magnetism between particles and allows them to disperse. Figure 2 illustrates the mechanism.
Steric stabilization works by adding uncharged polymer compound (or a mixture thereof) to the suspension. The particles are then surrounded by the suspended to create microcell states. Figure 4 depicts the mechanism diagram.
The Electrostatic stability mechanism is a combination the first two. That is, it involves the addition of a specific amount of polyelectrolyte into the suspension to adsorb that polyelectrolyte at the particle’s surfaces.
The pH value of polyelectrolyte is maximized to increase the dissociation rate of polyelectrolyte. Thus, when the polyelectrolyte coating the particle reaches saturated absorption, both of them work in concert to disperse the particles uniformly. Figure 3 illustrates the mechanism diagram.
Nanoparticle dispersion method
There are three phases to the dispersion of nanoparticles. First, liquid wetting is used to dissolve the solid particles. Second, external forces disperse larger particles into smaller ones. Third, stabilization of particles occurs. This ensures that dispersed particles do not re-aggregate. You have two options for dividing it according to the different dispersion mechanisms: Surface modification method or mechanical action.
The mechanical action technique refers the use or the apparatus to increase dispersion stability. To ensure that nanoparticles are evenly distributed within the medium, mechanical agitation dipersion can be described as a straightforward physical dispersion. This method uses only mechanical energy like external shear or impact force. Ultrasonic dipersion occurs when ultrasonic cavitation generates local high temperatures, high pressures or micro jets. This can reduce nano-action energy and stop nanoparticles becoming agglomerated and completely dispersing.
Inorganic substances modify the surface of nanoparticles
Inorganic substances are uniformly applied to the nanoparticle’s surfaces. To decrease its activity and protect it from damage, the active group of the hydroxyl on the surface of a nanoparticle can be shielded. Because the chemical reaction between inorganic and surface matter is not easy, the modified and the nanoparticle depend on van der Waals force.
Inorganic nanoparticles can be organically coated by using functional groups within organic molecules.
This edge discipline is related to many others, including organic and colloidal chemical chemistry as well as modern instrument analysis. A surface coating modification technique has been extensively used in the area of surface modification for nanometers. Additionally, the research results indicate that the technology’s future prospects are good. However, modifications to the mechanism, method, equipment, and characterisation of modification effects are all still in need of improvement. Unfortunately, many of the problems cannot be fixed fundamentally. Further research is essential. A nano surface modification technique is an important technology for creating new materials. This is due to changes in physical and chemical properties. Research and development in nano-technology are ongoing. They will be a force for good and help to improve society. The economic and other benefits.
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