Spreading and Retraction of Spilled Crude Oil on Sea Water

Physical and chemical aspects of “precursor films” spreading on water from natural bitumen

“…8(a), the precursor film spectrum has features also evident in the maltenes and asphaltene spectra, which can be identified in most crude oils. In particular, the precursor film infrared spectrum contains: (i) an enhanced C=O vibrational band at 1700-1725 cm -1 , possibly due to carboxylic acids [40], which is present at a lower level in the spectrum of the n-heptane maltenes spectrum, but absent in the corresponding asphaltene spectrum, suggesting that asphaltene is not for a major contributor to the precursor film; (ii) an enhanced band at 1600 cm -1 , assigned to C=C stretching modes, which suggests higher aromatic character than the maltenes [41]; (iii) a stronger sulfoxide (S=O) band than seen in maltenes and asphaltenes fractions at 1030 cm -1 [15]; and (iv) a small, broad O-H band at 3300 cm -1 (which could be due to water). Other bands in the 700-1000 cm -1 region can be attributed to aromatic vibration modes.…”

“…By considering the polar (p) and dispersion (d) contributions to surface and interfacial tensions, Takamura et al derived eq. 2 for the spreading coefficient [15], from which the importance of the polarity of the oil phase is more evident from the middle term on the right-hand side of this equation. Thus, polar oils or oil components with significant polar surface tension contributions ( ) will increase the spreading coefficient.…”

“…For conventional crude oils of relatively low viscosity, flow is driven by the positive spreading coefficients of the most polar molecules, and Marangoni coupling of the flow enables the whole oil to apparently spread spontaneously, with SOW typically found to be 17-28 mN/m [15] and sometimes significantly higher [16]. On the other hand, for more viscous heavy oils and bitumen, spreading of surface-active species by "edge diffusion" [12] occurs more rapidly than the higher viscosity major components.…”

Buoyancy and capillary effects on floating liquid lenses

“…Note that both L i and P i are not known a priori in Eqs. (10). These six constants and the drop radius, R d , must be determined consistently by solving all six equations plus the conservation of drop volume.…”

“…Fluid-fluid interactions between two immiscible liquids are common in nature and in many industrial processes. Pioneering work goes back at least to Benjamin Franklin [1], but a plethora of papers have been devoted to the spreading phenomenon of one liquid over another (see, e.g., Lord Rayleigh [2], Neumann and Wangerin [3], Hardy [4], Lyons [5], Langmuir [6], Miller [7], Zisman [8], Seeto et al [9], and Takamura et al [10]).…”