For the individual nonionic surfactant systems, the maximum interfacial excess concentration, minimum interfacial area per surfactant molecule, critical micelle concentration in the aqueous phase, efficiency and effectiveness of interfacial tension reduction, and standard free energy of adsorption and micellization were calculated and rationalized. For systems containing a binary mixture of nonionic surfactants, molecular interaction parameters in the mixed interfacial film and in the mixed micelle were calculated and discussed. Individual nonionic surfactants studied were C^EOe, C12EO4, C12EO3, C12EO2, and CigEOg. Binary surfactant mixtures studied were C12EO8/C12EO4, CuEOe/C^EOs, C12EO8/C12EO2, C^BOs/Cm-EOq, C16EO8/C12EO2, C^EOg/CgPY, C12EO8/C12PY, and C12EO8/C12EO2, where EO -C2H4O and PY -2-pyrrolidinone. Hydrocarbons used were hexadecane, dodecane, heptane, isooctane, heptamethylnonane, and cyclohexane.

This paper reviews current and emerging fabric softener technologies including various benefits that can be achieved by manipulating quat active structure, polymer/ quat active combination systems, single rinse products, consumer product forms, softening-through-the-wash, and fragrances used in fabric softeners. The technologies reviewed are aimed at the consumer market. Insights are provided into the drivers behind the technologies as well as their influence on market trends.

Measurements of the dynamic surface tension of seven surfactants (four organosilicones, two ‚conventional’︁ hydrocarbon‐based surfactants and an organosilicone + hydrocarbon‐based blend; 0.5 to 5.0 g litre−1) have been combined with data on the adhesion of their spray droplets to pea leaf. The latter were determined by a method enabling the surface age, and thus surface tension of the droplets at impact, to be calculated. Adhesion was directly related to the dynamic reduction in surface tension (2 to 50 mN m−1) prior to impact. The organosilicone surfactants and the blend reduced surface tension more rapidly and to lower values than did the organic surfactants. Adhesion was also inversely related to droplet size (110 to 880 μm diameter), droplet velocity (0.3 to 2.8 m s−1) and angle of incidence on the leaf (0 to 67.5 degrees). These physical factors were of less importance than surface tension in controlling adhesion. Relative adhesion varied among the surfactants both with their concentration and with surface tension. These findings are discussed with respect to their implications for the possible involvement of surface viscosity in the spray impaction process.

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