Preparation
The preparation of colloidal systems requires knowledge in surface and colloid chemistry, as well as knowledge in mechanical behavior of such systems.
Colloids can be prepared from top-down or from bottom-up. Top-down preparation involves the atomization of the substance to be dispersed in the continuous medium, while in the bottom-up process the particles are made to nucleate and grow to a previously defined size. In many bottom-up synthesis routes there are no specific instrumentation other than know-how and know-why.
High-pressure emulsifier
In a “high pressure emulsifier” emulsions are made by pumping the pre-emulsified system through two impinging jets. By applying a constant pressure drop fairly monodisperse systems can be obtained.
High-pressure reactor for phase inversion emulsification
This apparatus allows an emulsion to be inverted viz. from oil-in-water to water-in-oil or vice versa. This is a technique to achieve small emulsion droplets and is especially valuable if one of the fluids is viscous.
Milling equipment
Milling should be performed with care since the heat from the milling process might change the surface of the substance being milled, especially if the milling is performed in air such that the surface will become oxidized. Therefore milling equipment is often equipped with cooling devices as well as controlled atmosphere. Milling can also be performed through freeze granulation.