Effect of Water-Soluble Alcohols on Surfactant Aggregation in the C₁₂EO₈ System

Abstract

We investigated the effect of water-soluble alcohols (glycerol, propylene glycol, and 1-propanol) on the surfactant aggregation and its structure by phase study, surface tension measurement, small-angle X-ray scattering (SAXS) measurement, and pulsed field gradient NMR self-diffusion measurement. The phase behavior in the (water + glycerol)/C12EO8 system as a function of the glycerol content in water at constant temperature is similar to that in the water/C12EO8 system as a function of temperature, and a phase separation (clouding phenomenon) takes place at a high glycerol content. The phase separation was not observed in the other alcohol systems. However, a hexagonal liquid crystal (H1) changes to an isotropic solution (Wm) in all the systems with increasing the alcohol content. The SAXS measurement for the H1 and the Wm phases, and the self-diffusion measurement for the Wm phase suggest that the dehydration of the ethylene oxide chain takes place and the aggregates tend to grow with increasing glycerol content. On the other hand, propylene glycol or 1-propanol molecules tend to penetrate into the palisade layer of the aggregates and the micelles are downsized, and eventually they are broken into monomers with increasing the alcohol content. The critical micelle concentration measurement also supports the difference in the alcohol effects on the phase behavior in the aqueous nonionic surfactant system.

O/W Nano-Emulsion Formation Using an Isothermal Low-Energy Emulsification Method in a Mixture of Polyglycerol Polyricinoleate and Hexaglycerol Monolaurate with Glycerol System

“…Thus, the expansion of the sponge phase region observed in previous studies has been considered to be caused by increased hydrophobicity of MOPS in the presence of sugar. Glycerol also has been shown to decrease the cloud point of octaethylene glycerol dodecyl ether 23 .…”

Formulation, development, and optimization of a novel octyldodecanol-based nanoemulsion for transdermal delivery of ceramide IIIB

“…26,27 Third, some cosurfactants change their optimum curvature and decrease the elasticity of surfactant film by penetrating the hydrophilic head-group region of surfactant monolayers. 29,30 Glycerol affects the surfactant aggregation and its structure due to dehydration. 29 The other part of the cosurfactant molecules resides in the water and decreases the polarity of water by interfering with its hydrogen-bonding network.…”

“…29,30 Glycerol affects the surfactant aggregation and its structure due to dehydration. 29 The other part of the cosurfactant molecules resides in the water and decreases the polarity of water by interfering with its hydrogen-bonding network. 31,32 The mechanism of droplet formation has been partly attributed to the solubility and optimum curvature of the surfactants.…”

“…45 The TW80:glycerol weight ratio was the key factor influencing the appearance of nanoemulsions and affecting the area of nanoemulsion regions. High glycerol concentrations may dehydrate the polar heads of polysorbate molecules too quickly and intensely, 29 leading to high reduction in the hydrophilic-lipophilic balance of the surfactant and preventing their proper accommodation in the oil-water interface. 46 Glycerol contains three hydroxyl groups; therefore, an increase in glycerol concentration accompanied by a reduction in TW80 concentration made spontaneous breakup of the oil-water interface more difficult without a decrease in interfacial tension.…”

Phase Behavior and Froth Stability in a Water/Lysophospholipid System

“…The addition of water-soluble polyhydric alcohols often influences the surfactant self-assembled structure and the phase behavior due to direct incorporation in the selfassemblies or changing the solvent nature depending on the molecular structure of the polyhydric alcohols 30) . The effect of different polyhydric alcohols such as propyleneglycol (PG), glycerol (Gly) and 1,3-butanediol (BD) on the phase behavior of the aqueous lysophospholipid system is studied and the phase behavior is shown in .…”