Static and dynamic properties of surfactant films on natural waters

Oceanologia

关键词: Marine films;    Isotherms;    Virial equation;    Adsorption kinetics;    Relaxation processes;    Viscoelasticity;   

DOI  :  

来源: DOAJ

【 摘 要 】

The paper contains the results of natural surface film surface pressure - area experiments carried out in inland waters and shallow offshoreregions of the Baltic and Mediterranean Seas during 1990-99 under calm water conditions usingthe Langmuir trough - Wilhelmy filter paper plate system, which "cuts out" an undisturbed film-covered sea area without any initial physico-chemical sample processing. The limiting specific area A_lim (268–3157 Ų/molecule^-1)and mean molecular mass (0.65-9.7 kDa) of microlayer surfactants were determined from the 2D virial equation of stateapplied to the isotherms. Film structure signatures were derived from – A isothermhysteresis and application of the 2D polymer scaling theory. The stress-relaxation measurements revealed a two-step relaxationprocess at the interface with characteristic times ₁ (1.1–2.8) and ₂ (5.6-25.6) seconds suggesting the presence of diffusion-controlled and structural organization relaxation phenomena.The results demonstrate that natural films are a complex mixture of biomolecules covering a wide range of solubilities, surface activity and molecular mass with an apparent structural organization exhibiting a spatial and temporal variability.

【 授权许可】

Unknown