• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.37 no.1
• /
• pp.1-21
• /
• 2011

This review describes several kinds of emulsification methods for nanoemulsions and the application of nanoemulsions. Nanoemulsion droplet sizes fall typically in the range of 20 ~200 nm and show narrow size distributions. Although most of the publications on either oil-in-water (O/W) or water-in-oil (W/O) nanoemulsions have reported their formation by dispersion or high-energy emulsification methods, an increased interest is observed in the study of nano-emulsion formation by condensation or low-energy emulsification methods based on the phase transitions that take place during the emulsification process. Phase behaviour studies have shown that the size of the droplets is governed by the surfactant phase structure (bicontinuous microemulsion or lamellar) at the inversion point induced by either temperature or composition. Studies on nanoemulsion formation by the phase inversion temperature (PIT) method have shown a relation between minimum droplet size and complete solubilization of the oil in a microemulsion bicontinuous phase independently of whether the initial phase equilibrium is single or multiphase. Due to their small droplet size nanoemulsions possess stability against sedimentation or creaming with Ostwald ripening forming the main mechanism of nanoemulsion breakdown. An application of nanoemulsions is the preparation of nanoparticles using a polymerizable monomer as the disperse phase where nanoemulsion droplets act as nanoreactors, cosmetics and controlled drug delivery. In this review, we mainly focus on the cosmetics.

• Journal of Digital Convergence
• /
• v.13 no.4
• /
• pp.369-375
• /
• 2015

In this study, the formation potential and the stability of nano-emulsions were evaluated according to the structure of various cosmetic oils in Tween 80/Span 80 system using PIC method at 80 oC LP 70, Isopar H and Pripure 3759 of hydrocarbons were both form a stable nano-emulsion, particle size distribution of about 40 nm. A linear structure of silicone oil formed an unstable emulsion, but cyclic or short chain oil formed was a stable nano-emulsion. In ester oils, the particle size of emulsions increases with increasing molecular weight of oils and a stable nano-emulsion could not be obtained in the molecular weight of about 450. The particle size of the nano-emulsion against required HLB value for calculating in consideration of the lipophilic and hydrophilic oil was smaller in the HLB of 8-10.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.43 no.4
• /
• pp.273-279
• /
• 2017

In this study, low viscous O/W (oil-in-water) nano-emulsion with fatty acid and fatty alcohol was prepared by phase inversion emulsification method using Tween 80 and Span 80 widely used in cosmetic products. The particle size of the nano-emulsion was increased as increasing the concentration of fatty alcohol in oil phase. Adjusting the HLB of mixed surfactants, a stable nano-emulsion with a narrow size distribution was produced. Similar change in viscosity and electrical conductivity in both systems containing fatty acid and fatty alcohol was shown in the vicinity of the phase inversion point. However, high viscosity was shown in a wide range of different aqueous fraction unlike the system consisting only oils and surfactants. The low viscous nano-emulsion with less than 100 nm droplet size was stable for one month or more at room temperature. O/W nano-emulsions with low viscosity containing fatty acid or fatty alcohol produced by low-energy emulsification method can be widely used as formulations of cosmetics.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.40 no.3
• /
• pp.221-226
• /
• 2014

IIn this study, O/W type nano-emulsions were prepared by phospholipid-nonionic surfactant mixtures and octyldodecylmyristate using the phase transition low-energy emulsification method. The nano-emulsions were formed only in the very narrow area of the concentration of mixed surfactant and oil molar ratio of around 1 : 1. The particle size of the emulsions was decreased as adding the aqueous phase into the emulsions after phase inversion point unlike the emulsions formed only with nonionic surfactant. Nano-emulsion was stable at room temperature for more than a month. Thus, the nano-emulsions containing phospholipids can be widely used as a cosmetic formulations.

• Korean Chemical Engineering Research
• /
• v.47 no.1
• /
• pp.46-53
• /
• 2009

Phase equilibrium and dynamic behavior studies were performed in systems containing $C_{12}E_5$ nonionic surfactant solution and nonpolar hydrocarbon oil. The phase behavior result showed an oil-in-water(O/W) microemulsion(${\mu}E$) in equilibrium with excess oil phase at low temperatures and a water-in-oil(W/O) ${\mu}E$ in equilibrium with excess water phase at high temperatures. For intermediate temperatures a 3 phase region containing excess water, excess oil, and a middle-phase microemulsion was observed and the transition temperature was found to increase with an increase in the chain length of a hydrocarbon oil. Dynamic behavior at low temperatures showed that an oil drop size decreased linearly with time due to solubilization into micelles and the solubilization rate decreased with an increase in the chain length of a hydrocarbon oil. On the other hand, both spontaneous emulsification of water into oil phase and expansion of oil drop with time were observed because of diffusion of surfactant and water into oil phase. Under conditions of a 3 phase region including a middle-phase ${\mu}E$, both rapid solubilization and emulsification of oil into aqueous surfactant solution were found mainly due to the existence of ultra-low interfacial tension. Interfacial tensions were measured as a function of time for n-decane oil drops brought into contact with 1 wt% surfactant solution at $25^{\circ}C$. Both equilibrium interfacial tension and equilibration time were found to increase with an increase in the chain length of a hydrocarbon oil.

• Applied Chemistry for Engineering
• /
• v.20 no.5
• /
• pp.473-478
• /
• 2009

Phase equilibrium and dynamic behavior studies were performed on systems containing $C_{10}E_5$ nonionic surfactant solutions and nonpolar hydrocarbon oils. The phase behavior showed an oil in water (O/W) microemulsion (${\mu}E$) in equilibrium with excess oil phase at low temperatures and a water in oil (W/O) ${\mu}E$ in equilibrium with excess water phase at high temperatures. For intermediate temperatures a three-phase region containing excess water, excess oil, and a middle-phase microemulsion was observed and the transition temperature was found to increase with an increase in the chain length of a hydrocarbon oil. Dynamic behavior at low temperatures showed that an oil drop size decreased linearly with time due to solubilization into micelles and the solubilization rate decreased with an increase in the chain length of a hydrocarbon oil. On the other hand, both spontaneous emulsification of water into oil phase and expansion of oil drop were observed because of diffusion of surfactant and water into oil phase. Under conditions of a 3 phase region including a middle-phase ${\mu}E$, both rapid solubilization and emulsification of oil into aqueous solutions were found mainly due to the existence of ultra-low interfacial tension. Interfacial tensions were measured as a function of time for n-decane oil drops brought into contact with 1 wt% surfactant solution at $25^{\circ}C$. Both equilibrium interfacial tension and equilibration time increased with an increase in the chain length of a hydrocarbon oil.

• Applied Chemistry for Engineering
• /
• v.22 no.4
• /
• pp.416-422
• /
• 2011

In this study, the effect of cosurfactant on the phase equilibrium and dynamic behavior was studied in systems containing NP7 nonionic surfactant solutions and nonpolar hydrocarbon oils. All cosurfactants used during this study such as n-pentanol, n-octanol and n-decanol acted as a hydrophobic additive and thus promoted the transition from an oil in water (O/W) microemulsion (${\mu}E$) in equilibrium with an excess oil phase to a three-phase region containing excess water, excess oil, and a middle-phase microemulsion and further to a water in oil (W/O) ${\mu}E$ in equilibrium with the excess water phase. The transition temperature was found to decrease with both increases in the chain length and amount of addition of a cosurfactant. Dynamic behavior studies under O/W ${\mu}E$ conditions showed that an oil drop size decreased with time due to the solubilization into micelles. On the other hand, both the spontaneous emulsification of water into the oil phase and the expansion of oil drop were observed under W/O ${\mu}E$ conditions because of the diffusion of surfactant and water into the oil phase. Under conditions of a three-phase region including a middle-phase ${\mu}E$, both the rapid solubilization and emulsification of the oil into aqueous solutions were found mainly due to the existence of ultra-low interfacial tension. Dynamic interfacial tension measurements have been found to be in a good agreement with dynamic behavior results.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.48 no.1
• /
• pp.55-64
• /
• 2022

The potassium cream soap with fatty acid called cleaning foam has a crystal gel structure, and unlike an emulsion system, it is weak to shear stress and shows characteristics that are easily separated under high temperature storage conditions. The crystal gel structure of cleansing foams is significantly influenced by the nature and proportion of fatty acids, degree of neutralization, and the nature and proportion of polyols. In order to investigate the effect of these parameters on the crystal gel structure, a ternary system consisting of water/KOH/fatty acid was investigated in this study. The investigation of differential scanning calorimeter (DSC) revealed that the eutectic point was found at the ratio of myristic acid (MA) : stearic acid (SA) = 3 : 1 and ternary systems were the most stable at the eutectic point. However, the increase in fatty acid content had little effect on stability. On the basis of viscosity and polarized optical microscopy (POM) measurements, the optimum degree of neutralization was found to be about 75%. The system was stable when the melting point (T_m) of the ternary system was higher than the storage temperature and the crystal phase was transferred to lamellar gel phase, but the increase in fatty acid content had little effect on stability. The addition of polyols to the ternary system played an important role in changing the T_m and causing phase transition. The structure of the cleansing foams were confirmed through cryogenic scanning electron microscope (Cryo-SEM), small and wide angle X-ray scattering (SAXS and WAXS) analysis. Since butylene glycol (BG), propylene glycol (PG), and dipropylene glycol (DPG) lowered the T_m and hindered the lamellar gel formation, they were unsuitable for the formation of stable cleansing foam. In contrast, glycerin, PEG-400, and sorbitol increased the T_m, and facilitated the formation of lamellar gel phase, which led to a stable ternary system. Glycerin was found to be the most optimal agent to prepare a cleansing foam with enhanced stability.

• Journal of the Korean Applied Science and Technology
• /
• v.29 no.3
• /
• pp.486-494
• /
• 2012

Nano-emulsion with phase inversion temperature (PIT) emulsifying system was prepared to use rapeseed oil from originating Jeju in order to apply various cosmetic applications. Natural rape seed oil (NRSO) extraction was extracted using n-hexane as a solvent. NRSO extract showed a light yellowish color of viscous liquid as well as yield was $43{\pm}2.5%$. Acid value was $2.76{\pm}0.5$ and gravity was $0.89{\pm}0.05$. Droplet size of PIT-Yuche-NE with 20wt% of rapeseed oil was 50-120nm (average: $82{\pm}5.8nm$) and zeta potential was -29.5mV. It was thermodynamically good stable emulsion due to $(PEG)_{5-30}$fattyacidether. Some conclusions from the result of characteristic experiment were obtained as follows. First, the anti-oxidative activity was measured by free radical scavenging activity using DPPH (1,1-diphenyl-2-picrylhydrazyl radical). Anti-oxidative activity of PIT-Yuche-NE was $37.2{\pm}6.7%$ on 10mg/mL compared with PIT-Toco-NE (Natural tocopherol nano-emulsion, $28.8{\pm}6.5%$ on 10 mg/mL) and PIT-Nokcha-NE (Green tea extract nano-emulsion, $29.6{\pm}7.2%$ on 10mg/mL). Second, the collagen synthesis activity of PIT-Yuche-NE was $148{\pm}15.2%$ compared with PIT-Toco-NE (Natural tocopherol nano-emulsion, $121{\pm}13.5%$ on 10mg/mL) and PIT-Nokcha-NE (Green tea extract nano-emulsion, $95{\pm}12.7%$ on 10mg/mL). Third, the effectiveness of moisturizing activity of Yuche-CRM with Aramo-TS after 6 hours increase $47{\pm}3.9%$ (*p-value￡0.05, n=7) whereas Both Toco-CRM was $30{\pm}5.2%$ (*p-value￡0.05, n=7) and Nokcha-CRM was $35{\pm}4.5%$. Therefore, Yuche-CRM has higher moisturizing effect than other two creams. Finally, Nano-emulsion stabilizing rapeseed oil using PIT emulsifying system of this study can be used to apply cosmetics industry and pharmaceutical industry.