There are many types of calcium carbonate dispersants. According to their chemical composition,
mechanism of action and applicable scenarios, they can be roughly divided into
the following categories:
Surfactant dispersants:
This type of dispersant mainly reduces the surface tension of the liquid to make calcium carbonate
particles more easily dispersed in the liquid medium.
Common surfactants include anionic (such as sodium dodecyl sulfate), nonionic (such as polyoxyethylene
alkylphenol ether) and cationic (such as quaternary ammonium salts).
Surfactants adsorb on the surface of calcium carbonate particles to form a protective film to prevent the
aggregation of particles.
Polymer dispersants:
Polymer dispersants usually have longer molecular chains and can form steric hindrance between calcium
carbonate particles, effectively preventing particle aggregation.
Common polymer dispersants include sodium polyacrylate, polyvinyl alcohol, polycarboxylate, polyacrylate, etc.
This type of dispersant not only has a good dispersing effect, but also improves the stability and fluidity of the system.
Inorganic salt dispersants:
Inorganic salt dispersants mainly adjust the pH value or ionic strength of the solution to affect the charge state
on the surface of calcium carbonate particles, thereby achieving a
dispersing effect.
Common inorganic salt dispersants include phosphates (such as sodium hexametaphosphate), silicates
(such as sodium silicate), carbonates, etc.
This type of dispersant is usually cheaper, but the dispersing effect may not be as stable as that of organic dispersants.
Organic small molecule dispersants:
Organic small molecule dispersants usually have a lower molecular weight, but can form a strong interaction with the
surface of calcium carbonate particles to achieve a dispersing effect.
This type of dispersant may include organic small molecule compounds such as alcohols, esters, and amines.
Organic small molecule dispersants may have unique advantages in specific application scenarios, such as improving the
transparency of the system and reducing viscosity.
Polymer modified dispersants:
Polymer modified dispersants combine polymer compounds with the surface of calcium carbonate particles through
chemical reactions to form a stable protective layer to
prevent particle agglomeration.
This type of dispersant usually has excellent dispersing effect and stability, but the cost may be higher.
Common polymer modified dispersants include modified polyacrylates, modified polyvinyl alcohol, etc.
Nano-scale dispersants:
With the development of nanotechnology, nano-scale dispersants are gradually used in the dispersion of calcium carbonate.
Nano-scale dispersants usually have a higher specific surface area and stronger adsorption capacity, which can more effectively
prevent the agglomeration of calcium carbonate particles.
This type of dispersant has broad application prospects in high-performance coatings, plastics, rubber and other fields.
It should be noted that different types of calcium carbonate dispersants differ in performance, cost and application scenarios.
Therefore, when selecting calcium carbonate dispersants,
it is necessary to make comprehensive considerations based on specific application requirements and process conditions.
At the same time, it is also necessary to pay attention to factors
such as the compatibility, stability and environmental impact of the dispersant.
