HLB, CMC, and phase behavior as related to hydrophobe branching

How to Attain Ultralow Interfacial Tension and Three‐Phase Behavior with Surfactant Formulation for Enhanced Oil Recovery: A Review. Part 1. Optimum Formulation for Simple Surfactant–Oil–Water Ternary Systems

“…A similar effect takes place with so-called internal olefin sulfonates species [92]. In all cases, tail doubling results in an increase in hydrophobicity together with an increase in water solubility [92]-in practice, a fancy concomitance to improve surfactant performance with no precipitation penalty, as will be discussed in part 2 of this review.…”

“…On shifting the benzene from the extreme of the nC16 alkyl to its middle (i.e., on the 8th carbon atom), the r/K value has been found to increase by about 10 units, i.e., a hydrophobe increase equivalent to adding four carbons atoms in a single linear chain with benzene at the extreme [89]. A similar effect takes place with so-called internal olefin sulfonates species [92]. In all cases, tail doubling results in an increase in hydrophobicity together with an increase in water solubility [92]-in practice, a fancy concomitance to improve surfactant performance with no precipitation penalty, as will be discussed in part 2 of this review.…”

Ethylation of Di‐rhamnolipids: A Green Route to Produce Novel Sugar Fatty Acid Nonionic Surfactants

“…A relevant example of this equivalent is a n-alcohol ethoxylate with nine EO groups and 24 carbon atoms in the tail. Note that the C24 tail is known (observed in earlier studies [63,64] and reviewed recently [65]) to be roughly equivalent to a branched hydrophobe of two alkyl tails with ten carbon atoms each, which is the dominant structure of the hydrophobic moiety of ethyl di-rhamnolipids. Such an ethoxylated n-alcohol has a HLB of 7.3 according to Davies [41], which is smaller than the HLB of 8.7 calculated for the ethyl dirhamnolipids.…”

Optimal Surfactant Structures for Cosurfactant-Free Microemulston Systems I. C16and C14Guerbet Alcohol Hydrophobes

“…From extensive previous studies [10,[19][20][21][22][23][24][25][26][27][28][29][30], the following general results are obtained for the extremes in hydrophobe structure.…”