Surface pressure variation in triphenylmethane dye adsorbed merocyanine monolayers at the air-water interface

Surface pressure variations of merocyanine or arachidic acid monolayers formed at the air-water interface are investigated. Under the constant area condition, a marked increase of surface pressure is observed during the adsorption of triphenylmethane dyes from the subphase. The surface pressure variation is closely related to the molecular interaction and arrangement between the spreading and adsorbing materials. Experimental results and data, calculated by means of the molecular orbital method, of molecular interactions and the quantity of adsorbed molecules are compared.