Surfactant offers dispering by:
A)Electrostatic repulsion
B)Steric hindrance.
For the oil based suspension, a better dispersion can be achieved by steric hindrance.
1.Surfactants with higher charge density, proper molecular weight in comb shape or star shape are preferred.
2.Side chains of surfactants chosen should have a similar polarity with oil (vegetable oil, methyl ester oil ), so as to facilitate chains' extension and form steric hindrance.
3.Anchoring groups are better to be fasten adsorbed onto A.I particles on single site or multiple sites through ion bonding, covalent bonding, hydrogen bonding and van der waals.
Major types: phosphates, polycarboxylates, block polymer, comb shaped polymer
