Evolution of natural sea surface film structure as a tool for organic matter dynamics tracing

The paper contains the results of natural film experiments carried out on inland waters in the Dead Vistula catchment area during 2000–2002 using the integrated Langmuir trough–Wilhelmy plate system. The static film parameters result from the generalized scaling procedures applied to the surface pressure-area isotherms and surface pressure–temperature isochores. They appear to reflect in a quantitative and sensitive way the film composition (Alim, Mw, Eisoth), film solubility and the miscibility of its components (via R, ΔSc and y factors), kinetic mobility of surfactant molecules (βs, πk), and its surface concentration (πeq, Γeq). There is a reason to suggest that certain classes of film-forming components or “end-members” may dominate the static and dynamic surface properties. Variation in the surface rheological parameters of source-specific surfactants is postulated to reflect organic matter dynamics in natural waters and were measured for the Dead Vistula river, its tributaries and the adjacent sea coastal area. The obtained results demonstrate that natural films are o complex mixture of biopolymeric molecules covering a wide range of solubilities, surface activities and molecular masses with a complex interfacial architecture. For the first time, the apparent solvent polarity effect on the structure and surface parameters of ex-situ formed natural sea microlayer films was quantitatively evaluated by means of the author's scaling procedures applied to unique Brewster angle microscopy and Langmuir trough isotherm data on Mediterranean Sea samples obtained by others.