It is inevitable to use chemical germicidal agents like paraben, imidazolidinyl urea and phenoxyethanol to preserve the emulsions which is usually used in cosmetics. Although these chemical preservatives are good enough to reduce the microbiological contamination, they are irritative, allergenic to the skin. Several kinds of polyols are used in cosmetics as moisturizer and solvent. In this study, we evaluate the effects of polyols on anti-microbial activities, safety and resistant index. MIC(minimal inhibitory concentration) of polyols determined against 6 germs including Staphylococcus aureus. The order of MIC was PG ≅ DPG ≅ 1,3BG 〉 HG 〉 1,2-PD 〉 1,2-HD ≅ 1,2-OD. The 2~3 wt% of 1,2-HD(hexanediol) shows good anti-microbial effects in emulsions without allergenic response. Resistant index of 1,2-HD was less than 2 and this value was smaller than that of chemical preservatives. The mechanism of antimicrobilogical effect might be disturb the membrane of germs by investigating using electron microscope. Added to that, using this paradigm, low preservative contents, paraben-free system, and even preservative-free systems can be expected from these results.

In this study, the characteristics of emulsified fuel were studied. The emulsified fuel which was composed of water and diesel was manufactured by using homogenizer and ultrasonic generator. The more the percentage of water contents increases, the more the density increases to the emulsified fuel. However, the viscosity increased in the 60% of water contents and decreased in the 70% of water contents because the O/W type was formed. The 3 minutes's ultrasonic waves during the irradiation time was appropriate of 16,000 rpm. And the energy density of ultrasonic waves was 87.5J/g. The emulsion stability has improved in the lower temperature, the lower percentage of water contents, and the most stable emulsion state was obtained from 20%(w/w) of water contents. Also, the emulsion stability was related to the HLB values of emulsifiers. Especially, the HLB values of emulsifier were appropriate from 4 to 7 values.

The W/O emulsion was formed by mixing hydrophobic nonion surfactants of span 80 and tween 60 with kerosine, and by adding sodium silicate aqueous solution. Precipitating the W/O emulsion by sodium bicarbonate resulted in spherical silica particles. Shape and size distribution of silica particles were observed. The particles were spherical and they have narrow size distribution. Particle sizes were 9.29, 7.39 and 5.73 μm at homogenizer speed of 2500, 3000, and 3500 rpm, respectively. The particle size was decreased by increasing agitation speed due to the formation of emulsion droplet. At fixed agitation speed, absorbed paraffin oil weight were measured and the SiO2/Na2O mole ratio effects on particle size were investigated. Particle size was decreased by increasing the mole ratio of SiO2/Na2O.

In this work, the properties as polishing wax for automobile of O/W type microemulsion containing wax, liquid paraffine and quaternaryammonium salt was investigated. The microemulsions were prepared at 96~97℃ by the phase inversion method, and polyoxyethylene(20) sorbitan monooleate (POE(20)SMO) and distearyl dimethyl ammonium chloride(D.D.A.C) as the emulsifiers were used. The mean particle size of the rnicroemulsions was about 7±0.5nm and as the properties of polishing wax, gloss increased degree, water resistant gloss degree, initial and final contact angle after water resistance were tested. The result was that the value of water resistantance and contact angle were decreased with increasing amount of POE(20)SMO and D.D.A.C., while the gloss degree values did not affected. And the rnicroemulsion blended with mono ethylene glycol(MEG) of 5~15wt% showed smaller particle size and more stable particle size distribution than without MEG. Finally, this microemulsion showed more excellent values of gloss degree, the water resistant gloss degree and contact angle, than two kinds of commercial polishing wax for automobile.

에멀젼 구조가 변하는 에멀젼 변환은 이미 40년 전에 알려졌다. 에멀젼 변환에서는 O/W 에멀젼이 W/O 에멀젼으로, 또는 이와 반대로 구조가 변하므로 연석상과 분산상이 서로 바뀌게 된다. 그러나 3상 에멀젼에서는 이와 같은 에멀젼 변환뿐만 아니라 어떤 특정한 온도에서 연속상은 변하지 않고 분산상의 구조가 바뀌는 현상이 관찰되었다. 이 현상을 에멀젼이라고 불렀으며 에멀젼 전이가 일어나는 온도를 에멀젼 전이 온도라고 하였다. 에멀젼 전이는 이론적인 고찰의 결과이었으며 양친매성 분자/기름/물의 두 3성분계에 대해서 실험적으로 관찰하였다. 이는 이제까지 보고되지 않았던 새로운 현상이다. 본 논문에서는 에멀젼 전이와 에멀젼 전이를 비교 분석하였다.

Liquid crystalline phases were formed from acylglutamate; polyglyceryl-10 myristate and glycerine mixture and they were used as a base material for preparing an O/W emulsion. When an oil phase is added into the liquid crystalline phases, it was inserted into the dispersed liquid crystal droplets rather than stayed outside the liquid crystals, which can be known by the fact that the size of liquid crystal droplets increases with the increasing oil phase content. Along with the increase in the droplet size, the complex modulus increases from 100 to 350 pascals and the loss angle decreases from 60 to 24 degrees, from which it can be known that the increase in the internal phase volume results in the increase in the elastic property of oil in liquid crystalline-phases (O/LC). When the water phase was lastly added into the O/LC phase, the emulsification occurred to form a O/W emulsion and the averaged particle size of the O/W emulsion changes from 22.5nm to 538nm with the addition of water phase. The results from the droplet size measurements and stability tests under accelerated conditions such as high temperature show that the obtained O/W emulsion is very consistent with time.

Silver bromide particles from 50 to 200a in diameter are prepared by mixing two microemulsions contaning the precursor salts AgNO3 and KBr. The microemulsions are composed of AOT(bis(2-ethylhexyl) sodium sulfosuccinate), n-heptane and water. The particle diameters are measured on photomicrographs obtained by transmission electron microscopy. The size of the particles is generally larger than that of the water cores. The influence of both the concentration of precursor salts in the water cores of the microemulsoin and the size of these water cores on the size of the particles has been studied.

Aqueous polyurethane dispersion was synthesized using phosphorus compound which received significant attention for the replacement of halogenated flame retardants. In this study, polyols which have phosphorus moity in their structural unit were synthesized by two-step polycondensation reaction using dimethyl phenylphosphonate, ethylene glycols. adipic acid, and 1,4-butanediol. In the next step, polyurethane dispersion was prepared using these polyols, isophorone diisocyanate with dimethyl propionic acid. The particle size of polyurethane latex was reduced from 347 nm to 240 nm with increasing DMPA content. It was observed that the LOI values of prepared coatings increased from 27% to 35% with increasing phosphorus content.

Poly(oxypropylene-oxyethylene glycol) block copolymer(PBC) oil dispersant, which has low toxicity, high biodegradability, and an excellent dispersion efficiency to crude oils and weathered W/O emulsion was prepared by blending PBC, poly(oxyethylene) oleate, and sorbitan monooleate. The dispersing efficiency was measured by swirling flask method. The PBC oil dispersant had an excellent dispersing efficiency to weathered oil products formed as stable W/O emulsion, and the low toxicity, such as 4000 ppm to Oryzias Latipes(24 hr, TLM), Brine Shrimp Artemia(24 hr, TLM).

Silver nanoparticles was synthesized by the method of W/O microemulsions with AOT (bis(2-ethylhexyl) sodium sulfosuccinate). The nucleation particle growth and aggregation was controlled by the droplet exchange process. The intermicellar exchange reaction is varied by changing the AOT and the H2O concentration. The synthesized W/O microemulsions was found to give the nanoparticles, which was confirmed by SEM, TEM, particle-size-analyzer, and UV-spectrometer. The most stable particles was obtained at 0.056 mole AOT solution, and the particle size distribution was found in the range from 27 to 31 nm. The mean particle size was reduced by adding Tween 20 significantly, and distribution was found from 14 to 16 nm. And, It's size was reduced by cosurfactants as toluene and benzyl alcohol. In case of toluene and benzyl alcohol, the range of particle size was found 7~11 nm and 8~12 nm.

We studied on the preparation and evaluation of O/W type microemulsion containing "wax, liquid paraffine and quaternary ammonium salt". And also it was obtained to stability of microemulsions by mono ethylene glycol(MEG) addition. The microemulsions were generally prepared at 96~97℃ by the phase inversion method. We used polyoxyethylene(20) sorbitan monooleate(POE(20)SMO) and distearyl dimethyl ammonium chloride(D.D.A.C.) as the emulsifiers at microemulsion preparation. From the results, we could get best condition for microemulsion preparation, in case of oil phase, montanic ester wax ; 1.1wt%, paraffine wax ; 1.1wt%, liquid paraffine ; 3.1wt%, propylene glycol ; 0.6wt% and ethylene glycol monobutyl ether ; 0.6wt%, when the ratio(wt%) of D.D.A.C. and POE(20)SMO were 2 : 3. And also we could obtained that the distributed particle size of the final microemulsions were about 8±1.5nm and the mean particle size was 7±0.5nm. We got following results from final microemulsions that the percent of transmittance; 96~98% at 700nm. And the microemulsion blended with MEG of 5~15wt% showed smaller particle size and more stable distribution than non-containing MEG.