Adequate lather is an important factor to consumers when they select toiletries. Another preference is long-lasting and weak acidity (pH 4.5–6.0) on the skin and scalp, which maintains healthy normal skin conditions while suppressing the growth of undesirable microbes and skin irritation. These preferences are met by a noticeable trend in product development to formulate silicones, higher alcohols and a variety of functional materials into toiletries. However, such ingredients, along with primary surfactants, generally suppress lather, and their use can result in slow foaming or reduced volume of foam.1 Thus, there are strong demands from the industry for an ingredient such as an adjuvant surfactant that is compatible with the complicated and diverse formulae necessary to meet consumer demands for both long-lasting, weak acidity and lather. The author describes efforts to develop such a surfactant here.
Increasing Foam
Foaming is important to accelerate the cleaning power of products. While surfactants are used to blend oil-soluble materials with water to carry oils away, the act of foaming removes dirt. This combined effort is typically accomplished with surfactants and/or the addition of other adjuvants, e.g., surfactants having foam-boosting properties. Fatty acid alkanolamides (FAAs) commonly are used in cleaning products and are reported to increase foam volume based on a stabilization effect. Yet, in a preliminary in-house examination, all FAAs failed to significantly increase lathering rate, according to sensory evaluations.
