Acceleration of structural changes in monolayers by steroid hormones

As part of a general study of the influence of steroid hormones on the properties of monomolecular films on water, we have examined the surface viscosity η_s of films of mono-octadecyl phosphate (mOP) on solutions containing steroid hormones. Monolayers of mOP on water undergo polymerization which can be readily followed by measuring η_s as a function of time1. The reaction is pH-dependent which indicates that the polymerization is, at least in part, a result of interactions among the phosphate groups1,2. The results bear on the aggregation reaction within mOP films, and the question of whether steroid hormones are able to modify chemical reactions at surfaces, of which the aggregation reaction is an example.