Spontaneous emulsification of oil drops containing surfactants and medium-chain alcohols

Abstract

Spontaneous emulsification of mixtures of n-hexadecane, noctanol, and the pure nonionic surfactant C~2E6 brought into contact with water was observed using videomicroscopy. Relevant aspects of equilibrium phase behavior in this system were determined, and information on emulsion drop size and stability was obtained by turbidity measurements. It was found that small, uniform oil droplets and the most stable emulsions occurred when the entire original oil drop was converted to another phase -in this case a microemutsion -which subsequently became supersaturated in oil owing to diffusion of octanol into the aqueous phase. Spontaneous emulsification was also studied for mixtures of n-decane, n-heptanol, and tetradecyldimethylamine oxide contacting water. In this case, small droplets were formed when both the microemulsion and an intermediate lamellar liquid crystalline phase became supersaturated with oil.

Role of medium-chain fatty acids in the emulsification mechanistics of self-micro-emulsifying lipid formulations

“…Based on a study by Rang and Millar (1998, 1999) investigating the emulsification of oils containing hydrocarbon, nonionic surfactant and n -octanol, the following mechanism for the self-emulsification of Miglyol 812-Imwitor 988-Tagat TO system can be proposed, see Fig. 7b.…”

Role of Hydrophilic Surfactants in the Emulsification Mechanistics of Type Iii Self-Micro-Emulsifying Drug Delivery Systems (Smedds)

“…General considerations of the putative mechanisms which have been proposed to explain spontaneous and self-emulsification processes have been discussed thoroughly in many reports [3][4][30][31][32][33]. In practice, disruption of the oil-water interface is caused by penetration of water into the formulation through the network of aqueous channels or diffusion of hydrophilic components such as, cosolvents and hydrophilic surfactants away from the formulation into the aqueous phase see fig.…”

Droplet Formation and Growth Mechanisms in Reaction-Induced Spontaneous Emulsification of 3-(Trimethoxysilyl) Propyl Methacrylate

“…Diffusion and stranding has been observed in a number of oil–water systems with various salts, surfactants, and solvents to facilitate supersaturation. − Droplet nucleation occurs when the local composition becomes unstable, which can be identified through the phase diagram of the solution components. When spontaneous emulsification occurs through diffusion and stranding, a water-in-oil emulsion is often observed simultaneously with the oil-in-water emulsion, and the oil-in-water emulsion appears a certain distance below the oil–water interface. , We also observe that the oil droplets appear some distance from the oil–water interface (Figure b) and the presence of aqueous droplets in the oil phase.…”