Laponite: the alternative for stabilising oil-in-water emulsions

Laponite: the alternative for stabilising oil-in-water emulsions

Wednesday, 23 September, 2020

We have been familiar with Pickering’s emulsions since the early 20th century; nevertheless, in recent times they have been gaining traction owing to the benefits they provide compared to conventional emulsifiers.

Pickering’s emulsions consist of the stabilisation of the relevant emulsions by solid particles. We incorporate these solid particles into the interface between the dispersed phase and the continuous phase, thereby preventing dispersed phase coalescence. The morphology, internal interactions and the wettability of the particles determine the stability of the emulsion.

Comindex, S.A. offers Laponite in order to achieve Pickering’s oil-in-water emulsions. Laponite is synthetic clay, formed by sodium silicate, magnesium and lamellar lithium, which has a high purity and aspect ratio. Moreover, it is not hazardous to health or the environment, affording added value of essential importance in a range of areas, such as the cosmetics and detergent sectors.

A comparative analysis with other solid particles reveals that lamellar silicates such as Laponite make it possible to obtain emulsified particles with a size of 1-2 µm. Unlike conventional emulsifiers, the distribution of the emulsified particle size does not depend on the clay concentration, making it possible to reduce the volume of stabiliser used.

Moreover, with Laponite the emulsified particle size varies according to the shear strength applied. For finer emulsions, we need high shear strengths; whereas, with lower shear strengths we are able to produce stable emulsions with emulsified particles at a millimetric scale.

Some of the most common applications for this kind of emulsion include perfumes for detergent products, polishers, cosmetics products and air fresheners.

The incorporation of Laponite into the formulations is highly simple. Below we propose two indicative formulae, without the need to include conventional emulsifiers: the first is perfect for wheel polish and the second for emulsion of perfume in water.

WHEEL POLISH
	Component	Manufacturer	Function	Weight (g)
	Distilled water		Solvent	79.05
	Sodium chloride		Electrolyte	0.05
	LAPONITE RD	BYK	Emulsifier	0.90
	BYK-1797	BYK	Surface (silicone) protection and shine	20.00
			TOTAL	100.0

In a container with water, stir in the sodium chloride. Then add BYK-1797 and LAPONITE RD in that order without stirring. Lastly, stir the emulsion at 20,000 rpm for 10 minutes. The final liquid is smooth and white, developing a gentle thixotropic effect after a number of hours.

Wheel polish stabilised with Laponite RD

This formulation manages to suspend droplets of silicone oil in water at room temperature, thus avoiding the use of a conventional emulsifier while improving the water resistance exhibited by the end product. In addition, the rheological performance of Laponite makes it possible to achieve an easy-to-apply product in aerosol which does not suspend once applied. We can alter the rheology of the emulsion by changing the volume of Laponite RD in the formula, whereby the more we incorporate the more the end product will appear akin to a gel.

EMULSION OF PERFUME IN WATER
	Component	Manufacturer	Function	Weight (g)
	Distilled water		Solvent	78.75
	Sodium chloride		Electrolyte	0.05
	LAPONITE EP	BYK	Emulsifier	1.20
	Fragrance		Perfume in oil	20.00
			TOTAL	100.0

The dispersion procedure is the same as the above formulation, giving an emulsion similar to the one in the picture below.

Emulsion of perfume in water stabilised with Laponite EP

Accordingly, the use of Laponite to obtain oil-in-water emulsions offers a host of benefits when compared to conventional emulsion systems:

Simplification of formulations
Conventional surfactant- or emulsifier-free formulations
Room temperature processing
Lower production costs and times
Adjustable rheological profile

If you are interested in Laponite and its applications in detergents and other sectors, please contact our technical advisory team.

Subscription to eNews

Use your email address to subscribe to our newsletter and we will keep you up-to-date on the latest product developments, events and seminars.

Secondary menu