TY - JOUR
T1 - Does the Solvent in a Dispersant Impact the Efficiency of Crude-Oil Dispersion
AU - Fernandes, Jay C.
AU - Agrawal, Niti R.
AU - Aljirafi, Futoon O.
AU - Bothun, Geoffrey D.
AU - Mccormick, Alon V.
AU - John, Vijay T.
AU - Raghavan, Srinivasa R.
N1 - Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/12/17
Y1 - 2019/12/17
N2 - Dispersants, used in the mitigation of oil spills, are mixtures of amphiphilic molecules (surfactants) dissolved in a solvent. The recent large-scale use of dispersants has raised environmental concerns regarding the safety of these materials. In response to these concerns, our lab has developed a class of eco-friendly dispersants based on blends of the food-grade surfactants, soy lecithin (L) and Tween 80 (T), in a solvent. We have shown that these "L/T dispersants" are very efficient at dispersing crude oil into seawater. The solvent for dispersants is usually selected based on factors like toxicity, volatility, or viscosity of the overall mixture. However, with regard to the dispersion efficiency of crude oil, the solvent is considered to play a negligible role. In this paper, we re-examine the role of solvent in the L/T system and show that it can actually have a significant impact on the dispersion efficiency. That is, the dispersion efficiency can be altered from poor to excellent simply by varying the solvent while keeping the same blend of surfactants. We devise a systematic procedure for selecting the optimal solvents by utilizing Hansen solubility parameters. The optimal solvents are shown to have a high affinity for crude oil and limited hydrophilicity. Our analysis further enables us to identify solvents that combine high dispersion efficiency, good solubility of the L/T surfactants, a low toxicity profile, and a high flash point.
AB - Dispersants, used in the mitigation of oil spills, are mixtures of amphiphilic molecules (surfactants) dissolved in a solvent. The recent large-scale use of dispersants has raised environmental concerns regarding the safety of these materials. In response to these concerns, our lab has developed a class of eco-friendly dispersants based on blends of the food-grade surfactants, soy lecithin (L) and Tween 80 (T), in a solvent. We have shown that these "L/T dispersants" are very efficient at dispersing crude oil into seawater. The solvent for dispersants is usually selected based on factors like toxicity, volatility, or viscosity of the overall mixture. However, with regard to the dispersion efficiency of crude oil, the solvent is considered to play a negligible role. In this paper, we re-examine the role of solvent in the L/T system and show that it can actually have a significant impact on the dispersion efficiency. That is, the dispersion efficiency can be altered from poor to excellent simply by varying the solvent while keeping the same blend of surfactants. We devise a systematic procedure for selecting the optimal solvents by utilizing Hansen solubility parameters. The optimal solvents are shown to have a high affinity for crude oil and limited hydrophilicity. Our analysis further enables us to identify solvents that combine high dispersion efficiency, good solubility of the L/T surfactants, a low toxicity profile, and a high flash point.
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U2 - 10.1021/acs.langmuir.9b02184
DO - 10.1021/acs.langmuir.9b02184
M3 - Article
C2 - 31804836
AN - SCOPUS:85076250805
SN - 0743-7463
VL - 35
SP - 16630
EP - 16639
JO - Langmuir
JF - Langmuir
IS - 50
ER -
