In the context of home and personal care products, studying surfactant and mixed surfactant adsorption on model solid surfaces, which mimic real surfaces such as fabrics, hair and skin, are beginning to provide real insights into their applications in detergency, conditioning and lubrication. The outer surface of hair, the cuticle, is a mixture of proteins (keratin) and covalently attached fatty acid, 18-methyleicosanoic acid, 18-MEA; and surfactant adsorption on to that surface is key to conditioning and lubrication. We request NR beam time to characterise 18-MEA surfaces prepared by L-B deposition, and to investigate the adsorption of cationic surfactants onto that model hair surface.