four main types of emulsifier(chemical)

There are 4 main types of emulsifier(chemical):

– Anionic (O/W), this is where the hydrophilic head groups carry a negative charge. Examples: sodium stearate, sodium stearyl glutamate, glyceryl stearate SE. These types of emulsifiers are however quite old fashioned, not as versatile, some may need a higher pH but on the plus side they tend to be quite cheap.

– Cationic (O/W) emulsifiers are where the polar hydrophilic head groups carry a positive charge, such as behentrimonium methosulfate.  These emulsifiers tend to be used in conditioners and give a silky, velvet, powdery, dry feel.  They can be easier to preserve however some types, for example, the shorter chain monoalkyl analogues may cause irritation.

– Non-ionic emulsifiers (W/O or O/W) are the most common emulsifier type.  They are versatile and because they do not have an overall charge and so are compatible with other emulsifier types.  There is a wide range available and they are generally more stable to electrolytes.

– Polymeric emulsifiers. Examples: sepigel 305, sepiplus 400, simulgel, cosmedia ACE, viscoptima SE. This kind of emulsifier operates differently from the others.  The lipophilic portion of the polymer adsorbs at the oil-water interface, and the hydrophilic portion swells in the water forming a gel network around oil droplets.  They are used alone or in combination with traditional emulsifiers.  If used as sole emulsifier without waxy ingredients they create gel-creams, serums.  They have a number of advantages, they are cold processable and so save energy and are quicker to process.  They have a lower usage level than traditional emulsifiers.  However the main downside is they are usually sensitive to electrolytes and sometimes shear.  However this category of emulsifier is getting more and more popular and can also be used to stabilize and thicken as well as to emulsify.