TONY O’LENICK
Nascent Technologies Corporation, Lawrenceville Ga, USA

Abstract

The interaction of raw materials used in formulation is critical to the ability of the formulation to provide the desired benefits to the consumer. Appearance, rheology, wet comb, dry comb, ability to function in a laminar gel network or form a coacervate all depend upon these interactions.
Originally, the term Gemini Surfactant (GS) was coined to describe a dual hydrophobic tail surfactant. It has subsequently been expanded and applied to several multiple headed surfactants.
In this article the properties of two different Gemini surfactants with differing flexibility in their linkage groups are explained.

BACKGROUND
One of the many methods of dividing surfactants into groups is based upon the charge on the organic portion of the molecule. According to such a scheme surfactants are anionic (for example sodium laureth 3 sulfate), cationic (for example stearalkonium chloride), nonionic (for example PEG 12 dimethicone), or amphoteric (for example cocamidopropyl betaine).

Surfactants are used in a variety of formulations, but rarely used alone. A look at a typical shampoo bottle will show numerous materials that make up a formulation. The functionality of the shampoo depends not only on the nature of each ingredient in the formulation, but as importantly the interactions between the ingredients. It is the nature of these interactions that provides among other things optimum detergency, foam, wetting and viscosity. Consumer perception of the attributes given by the formulator to a product makes for product success or failures in the market. Consequently, it is good to critical to the cosmetic chemist’s career to understand the interactions between ingredients.

A commonly understood interaction is the one that occur ...