%0 Journal Article
%T Elastic Properties of Natural Sea Surface Films Incorporated with Solid Dust Particles: Model Baltic Sea Studies
%A Adriana Z. Mazurek
%A Stanis£¿aw J. Pogorzelski
%J International Journal of Oceanography
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/638240
%X Floating dust-originated solid particles at air-water interfaces will interact with one another and disturb the smoothness of such a composite surface affecting its dilational elasticity. To quantify the effect, surface pressure ( ) versus film area ( ) isotherm, and stress-relaxation ( -time) measurements were performed for monoparticulate layers of the model hydrophobic material (of ¦Ìm-diameter and differentiated hydrophobicity corresponding to the water contact angles (CA) ranging from 60 to 140¡ã) deposited at surfaces of surfactant-containing original seawater and were studied with a Langmuir trough system. The composite surface dilational modulus predicted from the theoretical approach, in which natural dust load signatures (particle number flux, daily deposition rate, and diameter spectra) originated from in situ field studies performed along Baltic Sea near-shore line stations, agreed well with the direct experimentally derived data. The presence of seawater surfactants affected wettability of the solid material which was evaluated with different CA techniques applicable to powdered samples. Surface energetics of the particle-subphase interactions was expressed in terms of the particle removal energy, contact cross-sectional areas, collapse energies, and so forth. The hydrophobic particles incorporation at a sea surface film structure increased the elasticity modulus by a factor (1.29¨C1.58). The particle-covered seawater revealed a viscoelastic behavior with the characteristic relaxation times ranging from 2.6 to 68.5£¿sec. 1. Introduction The atmospheric transport and deposition of mineral particles strongly influence the physics and chemistry of the marine atmosphere, and the biogeochemical cycles in seawater. So far, our emphasis has been closed on the multicomponent character of natural surfactant films, and the consequent complexities involved in any attempt to predict the interfacial viscoelastic properties playing a crucial role in modeling of physical systems with surface film-mediated interfaces. A variation in the surface rheological parameters of the natural surfactant seawater films has been conceived as a different in source of surfactant materials and in physical dynamics reflecting organic matter migration, degradation, and spatial-temporal dynamics in natural waters [1]. In nearly all cases, uniform, homogeneous surfaces have been studied. However, in ¡°real¡± systems, in technology, biology, and oceanography, surfaces are very often non-uniform. For instance, a flat surface containing a surfactant monolayer which has undergone a
%U http://www.hindawi.com/journals/ijocean/2012/638240/