The association of α-monoglycerides in nonaqueous solvents

Aggregation response of triglyceride hydrolysis products in cyclohexane and triolein

“…In the current work, only monopalmitin in cyclohexane system formed clear aggregates and had a cmc of 14 mM based on numerical fitting. Previously, Konno et al 15 26 , are likewise in good agreement with the current findings; however, their measured concentration range is extremely narrow. Finally, Shrestha et al 28 investigated monomyristin/cyclohexane system (5 wt %, 70 • C) with SAXS and found the aggregates to be prolate ellipsoids with maximum dimensions of 2.8 nm.…”

“…Interestingly, replacing cyclohexane with a solvent containing hydrogen bonding sites appears to prevent the formation of large aggregates, even for those surfactants that have two hydroxyl groups per surfactant (monopalmitin). Actually, this mirrors the findings of Debye and coworkers 22,26 who investigated the aggregation tendency and hydrogen bonding of monoglycerides in benzene, carbon tetrachloride and chloroform. They found evidence of aggregation and intermolecular hydrogen bonding in benzene and carbon tetrachloride but not in chloroform 22,26 .…”

“…Experimentally, the self-assembly of monoglycerides in nonpolar media has been studied extensively 15,22,[25][26][27][28][29][30][31][32] in various hydrocarbon and triglyceride solvents but only a few works address aggregate formation of diglycerides and fatty acids 21,[33][34][35] . Vapor pressure osmometry, calorimetry, light scattering, and small angle X-ray scattering (SAXS) studies indicate that small to medium sized reverse micelles of monoglycerides form in a wide range of hydrocarbon solvents 15,22,[25][26][27][28][29] . The morphology of the aggregates can be controlled through temperature, solvent structure, and polar impurities 22,26,28,36 .…”

“…Vapor pressure osmometry, calorimetry, light scattering, and small angle X-ray scattering (SAXS) studies indicate that small to medium sized reverse micelles of monoglycerides form in a wide range of hydrocarbon solvents 15,22,[25][26][27][28][29] . The morphology of the aggregates can be controlled through temperature, solvent structure, and polar impurities 22,26,28,36 . In vegetable oils, monoglycerides can form inverse lamellar structures [30][31][32] , which dissolve to form an isotropic fluid-like phase at a temperature dependent on the surfactant structure, concentration, and water content 30,31 .…”

Critical micelle concentrations of aqueous surfactant systems

“…They are grouped together since they often involve problems of carbon dioxide contamination as well as salt bridges. 9. Other bulk properties that have been used to determine CMC's are density (23) based generally on magnetic float methods plotted directly as DENSITY (17) or after conversion to PARTIAL VOLUME (6) and ultrasonic VELOCITY OF SOUND (10 Other dyes which have been used in this method are Fluorescein -FL (2), Erythrosin -ERTS (7), dichlorofluorescein -DCLF (9), Benzopurpurine 4B -BZP4 (11), Bromphenol Blue -BRPB (21), Skyblue FF -SKYB (43), Eosin -EOSN (51), Indophenol -INPX (129) and, included because it performs the same function although not a dye in the strict sense, Iodine -12 (52). There is also unspecified VISUAL SPECTR CHNGE (27).…”