Do you know how to test the effect of dispersant dosage on dispersion performance? Some literature suggests using surface tension. Some say to use viscosity method. Is viscosity measurement method acceptable? However, I don't want to test it. It's best to use different amounts of dispersants to disperse titanium dioxide or graphite. Let it sit for how long before layering begins. If layering is possible, usually adding 1% of the pigment, how long does it take? Can it be a few months?
Generally speaking, there are the following testing methods:
1. Test the covering power of titanium dioxide, the fineness after grinding, and the color fading power of the pigment. Viscosity testing can also be used to determine.
2. Based on personal experience, the most effective method for determining the system of grinding color paste is through grinding. The dispersibility can be judged based on the time required to grind to the same fineness. You can also grind for the same amount of time and observe the fineness, covering power, etc. to compare the dispersion effect. This evaluation is the most practical, because the application performance of the final grading powder depends on this. Explain that the dispersibility of different dispersants varies in different systems, and specific testing is still necessary.
3. It can measure absorbance, and when the amount of pigment is constant, those with higher absorbance have better dispersibility. It may be difficult to distinguish at first, but you can centrifuge for a period of time before comparing, so that you can compare at the same level.
4. You can choose to compare at a certain temperature, such as 70 degrees or 80 degrees, which can accelerate the experimental process.
The definition of dispersant is a substance that can reduce the aggregation of solid or liquid particles in a dispersed system. Adding dispersants and suspensions in the preparation of emulsions and wettable powders can easily form dispersions and suspensions, while maintaining the relative stability of the dispersion system.
Additives that can improve and enhance the dispersibility of solid or liquid materials. When grinding solid dyes, adding dispersants helps to pulverize the particles and prevent them from coalescing, thus maintaining the stability of the dispersion. Oil liquids that are insoluble in water can disperse into very small droplets under high shear force stirring. After stopping stirring, they quickly separate under the action of interfacial tension. However, after adding a dispersant and stirring, a stable emulsion can be formed. Its main function is to reduce the interfacial tension between liquid-liquid and solid-liquid. Therefore, dispersants are also surfactants. The types include anionic, cationic, nonionic, amphoteric, and polymeric. Anionic type is most commonly used.
