• Journal of Microbiology and Biotechnology
• /
• v.14 no.4
• /
• pp.673-679
• /
• 2004

A microbial cryoprotectant formulation using a W/O/W multiple emulsion system was developed. The psychrotolerant microorganism, B4, isolated from soil in South Korea, was observed by the drop freezing method, in which the microorganism sample inhibited ice nucleation activity. The antifreeze activity was eliminated when the microorganism sample was treated with protease, indicating that the antifreeze activity was due to the presence of antifreeze protein. The result of the l6S rDNA sequencing indicated the B4 strain was most closely related to a species of the genus Bacillus. Culture broth of B4 strain (Bacillus sp.) and rapeseed oil containing 1 % polyglycerine polyricinolate (PGPR) were used as core and wall material, respectively. The most stable W/O emulsion was prepared at a core/oil ratio of 1:2. The highest W/O/W emulsion stability was achieved when the primary emulsion to external aqueous phase containing 0.5% caster oil polyoxyethylene ether $(COG25^{TM})$ ratio was 1:1. Microcrystalline cellulose showed better W/O/W emulsion stability than other polymer types. The viability of cells in a W/O/W emulsion was higher than free cells during storage at $37^\circ{C}$. An acidic pH and UV exposure decreased the viability of free cells, but cells in W/O/W emulsion were more stable under these conditions.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.44 no.1
• /
• pp.37-42
• /
• 2012

This study was carried in order to manufacture the high quality coated paper. High quality includes not only physical and optical properties of coated paper but also final print quality. In this study, new acrylic-styrene emulsion was polymerized in laboratory and compared with conventional styrene-butadiene latex. Low-shear viscosity of coating color was decreased with increasing acrylic-emulsion dosage. Small amount of acrylic emulsion addition increased water retention, but further addition decreased it. Acrylic-emulsion addition improved paper gloss, brightness and whiteness, but decreased PPS and opacity slightly. Ink gloss was increased with using No. 3 acrylic-emulsion due to lower ink setting properties. However No. 1 and 2 emulsion showed the opposite result. Surface strength of coated paper was increased with using No. 3 acrylic-emulsion. These results indicate that high quality coated paper can be manufactured with using No. 3 acrylic-emulsion.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.24 no.3
• /
• pp.111-115
• /
• 1998

We investigated the stability of all-trans-retinol on the liquid crystalline O/W emulsion composed of mainly alkyl polyglycerine, alkyl polyglucose and glycerine, and compared the activity of all-trans-retinol in the various forms of liquid crystal. Under certain conditions, novel liquid crystalline gel was formed around oil droplets, and layers of this liquid crystalline gel were very wide and rigid. (SWLC; Super Wide Liquid Crystal) SWLC was very helpful to stabilize retinol in O/W emulsion. After storage at 45 C for 4 weeks, all-trans-retinol in O/W emulsion composed of SWLC retained above 85% of the activity upon HPLC analysis, whereas those within no liquid crystalline emulsion gave 47% and normal liquid crystalline emulsion composed of fatty alcohols gave 40 60%. Retinol in oil phase is nealy insoluble in pure water, but in cosmetic emulsion systems can be slightly solubilized into water because emulsifiers and polyols in emulsion systems function as solubilizers. In this case, water in outer phase acts as a media for oxygen transporation$.$and thus destabilizes retinol. As a result, retinol in O/W emulsion has a tendency to become unstable. SWLC surrounding oil droplet which contains retinol is wide and rigid, therefore reduces contact between inner phase and outer phase To make SWLC, properties of emulsifiers are very important phase transition temperature should be high, and the structure of surfactants should be bulky, and their ratio should be suitable to make rigid and wide liquid crystalline gel layer in order to reduce contact between retinol in inner phase and water in outer phase.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.23 no.3
• /
• pp.263-270
• /
• 2015

Using Diesel-Water Emulsion fuel in commercial diesel engine can reduce NOx and soot when it is injected through the injector. Because water in Diesel-Water Emulsion fuel is vaporized ahead of diesel particle and it cause decrease of combustion temperature. Furthermore, research about the possibility of applicating Diesel-Water Emulsion fuels to commercial diesel engine is demanded in order to prove that Diesel-Water Emulsion fuel is able to apply commercial diesel engine without any replacement of equipments. This research analyzed applicable possibility of Diesel-Water Emulsion fuels to commercial diesel engine's fuel injection system refering injection and spray characteristics. In this research, there are 3 experiments, that is injection quantity, spray visualization, and injection rate. Diesel-Water Emulsion fuel has less injection quantities compared to diesel fuel, and spray penetration length is more longer than diesel. Furthermore, emulsion fuels have less dispersed than diesel fuel. In conclusion, comparing with diesel fuel with only spray characteristics, Diesel-Water Emulsion fuel has bad effects about dispersion and vaporization.

• The Korean Journal of Food And Nutrition
• /
• v.34 no.6
• /
• pp.561-567
• /
• 2021

Curcumin is not soluble in water. Therefore, curcumin emulsion that can dissolve well in water were prepared using multi-emulsification technology, and the antioxidant activities and physical properties of emulsion were measured. Although curcumin was not dissolved in water, it was confirmed to be well dispersed in water when prepared in an aqueous dispersion curcumin emulsion. After dissolving curcumin using water and ethanol as solvents, respectively, the DPPH and ABTS radical scavenging abilities of the filtrate and the curcumin emulsion were measured. Because it was not dissolved in water, activities were not shown. However, when curcumin was dissolved in ethanol, the activities increased as the concentration of curcumin increased. On the other hand, when the curcumin emulsion was dissolved in water, it was found to have abilities. The curcumin emulsion was nano-homogenized and the size and distribution of the emulsified spheres were measured. It was confirmed to be nano-sized as it appeared as 9.083 nm/100%. In the results of the DPPH radical and ABTS radical scavenging abilities of curcumin nano-emulsion, it was confirmed that there was no change in the antioxidant abilities. In conclusion, water-dispersible curcumin prepared using multi-emulsification technology, and it was confirmed to exhibit antioxidant activity and emulsion stability.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.4
• /
• pp.533-541
• /
• 2016

Effect of polyphenols-rich cacao extract (CE) on lipid hydrolysis by pancreatic lipase was investigated by pH-stat digestion. Two types of substrate (oil vs. emulsion) prepared from soybean oil and CE were studied as types I and II. In the case of type I, addition of CE did not show retardation of lipid hydrolysis, showing that pancreatic lipase was not inhibited. Final digestibility rate (${\Phi}$ max, %) and initial rate (mM/s) of the 24-h aged control (52.31%, 0.03 mM/s) were similar to those of the CE-added sample (58.88%, 0.03 mM/s). However, in the case of typeII, the hydrolysis rates of the control and CE-added emulsion showed distinct differences as aging time increased to 43 days, showing lower digestion in the CE-added emulsion than the control. After 43 days, ${\Phi}$ max values of the control and CE-added emulsion were 92.13% and 77.68%, respectively.

• Applied Chemistry for Engineering
• /
• v.17 no.2
• /
• pp.132-137
• /
• 2006

Polyurethane acrylate hybrid emulsions were prepared by seeded polymerization techniques. In the synthesis, seeded polyurethane dispersion containing a carboxylic group was used to endow hydrophilicity to the hybrid emulsion and various acrylates such as methyl methacrylate (MMA), 2-hydroxy ethylmethacrylate (2-HEMA), n-butyl acrylate (n-BA) and acrylic acid (AAc) were used to endow hydrophobicity. The particle size and distribution of various emulsion particles such as polyurethane acrylate hybrid emulsion, polyurethane dispersion homopolymer, acrylate emulsion, and physical blending emulsion were measured by a particle size analyzer. The average particle size of hybrid emulsion was greater than physical blending emulsion. And tensile strength, 100% modulus, elongation, and swelling properties of the polyurethane acrylate hybrid emulsion were studied and compared with those of polyurethane homopolymer, acrylate emulsion, and physically blended compositor, respectively. To improve chemical and physical resistance, this paper review a melamine hardener and compares it for effects on the physical properties of cured coating.

• International Journal of Highway Engineering
• /
• v.17 no.2
• /
• pp.39-46
• /
• 2015

PURPOSES: The objectives of this study were to develop a new polymer-modified emulsion for application to tack coats and to evaluate its properties by comparing it with other types of asphalt emulsions, with the goal of providing an enhanced tack coat material for use in construction. METHODS: Modified asphalt binders were developed from using SBS and SBR latex in the laboratory, and their fundamental properties, such as their penetration index and PG grade, were evaluated. Based on the properties, a new tack coat material was developed. To evaluate the newly developed asphalt emulsion, the bonding strength between the two layers of HMA was measured by applying a uniaxial tensile test and shear test. For the tests, a total of four different conditions were applied to the specimens, including the developed asphalt emulsion, latex modified asphalt emulsion, conventional asphalt emulsion, and non-tack coating. RESULTS AND CONCLUSIONS: Overall, the developed asphalt emulsion exhibits the best bonding strength behavior among all of the three types. Also, the two types of polymer-modified emulsions were found to be better for application for use as a tack coat than a conventional emulsion. Especially, at a high temperature ($50^{\circ}C$), the conventional asphalt emulsion no longer acts as a tack coating material. Therefore, the polymer-modified emulsion should be considered for application to tack coat construction during the summer.

• Journal of Microbiology and Biotechnology
• /
• v.15 no.1
• /
• pp.29-34
• /
• 2005

W/O/W (water-in-oil-in-water) type multiple emulsion was applied to improve the storage stability of an antagonistic microorganism, Burkholderia gladioli. Encapsulation of microorganism into a W/O/W emulsion was conducted by using a two-step emulsification method. W/O/W emulsion was prepared by the incorporation of B. gladioli into rapeseed oil and the addition of polyglycerin polyriconolate (PGPR) and castor oil polyoxyethylene (COG 25) as the primary and secondary emulsifier, respectively. Microcrystalline cellulose was used as an emulsion stabilizer. To evaluate the usefulness of W/O/W emulsion formulation as a microbial pesticide for controlling the bacterial wilt pathogen (Ralstonia solanacearum), the storage stability and antagonistic activity of emulsion formulation were tested in vitro. The storage stability test revealed that the viability of formulated cells in emulsion was higher than that of unformulated cells in culture broth. At $4^{\circ}C$, the viabilities of formulated cells and unformulated cells at the end of 20 weeks decreased to about 2 and 5 log cycles, respectively. At $37^{\circ}C$, the viability of formulated cells decreased to only 2 log cycles at the end of storage. On the other hand, the viable cells in culture broth were not detected after 13 weeks. In activity test, formulated cells in emulsion were more effective in inhibiting the growth of pathogen than unformulated cells in culture broth. Unformulated cells completely lost their antagonistic activity during storage under similar conditions. The W/O/W multiple emulsion formulation was shown to be useful as the novel liquid formulation for biological control.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.11
• /
• pp.1465-1471
• /
• 2008

This study was carried out to make water-soluble tocopherol emulsion which can be applicable directly in water. The molecular weight of tocopherol was 340 to 360 and tocopherol emulsion model was decided as O/O/W/W type. In correlation between stability of emulsion and surface tension, the stability in surface tension of emulsion was from 40 to 46 dyne/cm. In the case of lower than 40 dyne/cm of surface tension, the stability of the emulsion was lower. Lipophilic surfactants, especially for a polyglycerine polyricinoleate in 20%, 30% and 40% tocopherol emulsion, was the most effective in emulsion stability. A higher stability of the emulsion among hydrophilic surfactants in the tocopherol emulsion was obtained in the following order; polyglycerine monostearate> polyglycerine monooleate> polyoxyethylene (20) sorbitan monooleate$\geq$ polyoxyethylene (20) sorbitan monolaurate.