Three-Phase Behavior in a Mixed Sucrose Alkanoate and Polyethyleneglycol Alkyl Ether System

Sugar-Ester Nonionic Microemulsion: Structural Characterization

“…In almost all nonionic microemulsions the nonionic surfactants used are ethoxylated surfactants, such as ethoxylated alcohols, acids and fats, monoglycerides, and sorbitan esters. However, only a limited amount of work was conducted on the polyol type of nonionic surfactants, such as glucoside ethers or sucrose esters of fatty acids (8)(9)(10). These surfactants are biodegradable and formed from renewable sources such as fatty acids and sugars.…”

“…Consequently, increasing the temperature does not induce a phase inversion in microemulsion systems based on sucrose esters, as was observed in microemulsions based on alkyl ethoxylates. Temperature-insensitive sucrose-ester-based microemulsions are described in the literature (8,11,12). In most cases a paraffinic oil phase was used and the surfactants were mostly mixtures of ethoxylated alcohols and sucrose esters.…”

Effect of Adding an Amphiphilic Solubilization Improver, Sucrose Distearate, on the Solubilization Capacity of Nonionic Microemulsions

“…As is shown in Fig. 3, the solubilization of water and oil in microemulsions is considerably improved upon addition of 2C 18 SE, but not upon addition of C 18 SE. Moreover, the threephase temperature is not largely shifted.…”

“…If the considerable amount of surfactant is monomerically dissolved in oil or water, the apparent solubilization capacity decreases. Hence, it is possible that the improvement of solubilization capacity in the C 12 EO 6 /2C 18 SE system arises from the decrease in the monomeric solubility, since the HLB temperature slightly decreases with increasing 2C 18 SE fraction in total surfactant and the monomeric solubility of nonionic surfactant in solvent is normally low at low temperature (6,18). The minimum surfactant concentrations in the three-phase region of the 2C 18 SEabsent system are about 1 wt% (±0.25%), which approximate the monomeric solubilities of surfactant in water and oil (24).…”

“…When an ASI is introduced in a given microemulsion system, the solubilization capacity of microemulsions is improved without a change in the relative HLB of the mixed surfactant. Sucrose surfactants can reduce the interfacial area per molecule when these are introduced into a polyoxyethylene-type surfactant layer (17) and the monomeric solubility in oil is low due to the strong hydrophilicity of its sucrose unit (4,18).…”