• Journal of the Korean Applied Science and Technology
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• v.13 no.3
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• pp.61-71
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• 1996

In acid-catalyzed acetal cyclization of long aliphatic aldehydes($R=n-C_7H_{15}$ ; $n-C_9H_{19}$ ; $n-C_{11}H_{23}$) with 1,1,1-tris(hydroxymethyl)propane, 2-alkyl-5-hydroxymethyl-5-ethyl-1,3-dioxanes were obtained. The final products, sodium 2-alkyl-5-(sulfonatedpropylethermethyl)-5-ethyl-1,3-propanesultion in the presence of sodium hydride. These compounds were a new group of destructible surfactants which were readily hydrolyzed and oxidized in natural water reservoirs. Physical properties of these new compounds involved some surface properties such as Krafft point(Kp), critical micelle concentration(cmc), surface tension of aqueous solutions near cmc(${\gamma}_{min}$), foaming power, emulsion power and hydrolysis properties were determined. The destructible surfactants containing 1,3-dioxane ring were synthesized to about $85{\pm}5.5%$ yield. The cmc values of the compounds by ring method were assumed to $0.5{\sim}5.0{\times}10^{-3}mol/L$ range and surface tensions at cmc were $29.5{\sim}33.0dyne/cm$ respectively at $25^{\circ}C$. The foaming power and foam stability were $170{\sim}230mm$ and $52{\sim}135mm$ respectively at $1{\times}10^{-2}mol/L$, foam was occurred rarely below $1{\times}10^{-3}mol/L$. The emulsion property of liquid paraffin was better than that of soybean oil. For hydrolysis property with ph and time, these compounds were decomposed within about 200minutes at $ph1{\sim}2$. Hopefully these compounds are expected to be a good O/W emulsifier that have decomposability in acid and may be used in the process which do not need foaming.

• Journal of the Korean Applied Science and Technology
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• v.11 no.1
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• pp.79-85
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• 1994

All the activities and physical properties including surface tension' foaming power, foam stability, emulsifying power, dispersion effect of 3-(N, N-dimethyl N-alkylammonio)-2-hydroxyY-1-propane sulfonate (HSB)류와 3-CN-alkylamidopropyl-N,N-dimethylamm-onjo)-2-hydroxy-1-propane sulfonate (APSB) aquous solution were measured and critical micelle concentration was evaluated. Their cmc of hydroxy sulfobetaine derivatives evaluated by the surface tension method was $1.0{\times}10^{-3}{\sim}1.0{\times}10^{-4}$ mol/l, and surface tension of the aquous solution was decreased to $27{\sim}38dyne/cm$. The experimental results for foaming power, foam stability, emulsifying power in liquid paraffin showed a good surface active properties, especially, dispersion effect in ferric oxide exhibited some efficient surface active properties, and then it would be expected to application as detergent and dispersion agent.

• Polymer(Korea)
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• v.37 no.3
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• pp.332-341
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• 2013

H-shaped amphiphilic pentablock copolymers $(PSt)_2-b-PCL-b-PEO-b-PCL-b-(PSt)_2$ was synthesized via chemoenzymatic method by combining enzyme-catalyzed ring-opening polymerization (eROP) of ${\varepsilon}$-caprolactone (${\varepsilon}$-CL) and atom transfer radical polymerization (ATRP) of styrene. By this process, we obtained copolymers with controlled molecular weight and low polydispersity. The structure and composition of the obtained copolymers were characterized by nuclear magnetic resonance (NMR), gel permeation chromatography (GPC) and infrared spectroscopy analysis (IR). The crystallization behavior of the copolymers was analyzed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The crystallization behavior of the H-shaped block copolymers demonstrated a PCL dominate crystallization. The self-assembly behavior of the copolymers was investigated in aqueous media. The hydrodynamic diameters of the copolymer micelles in aqueous solution were measured by dynamic light scattering (DLS). The morphology of the copolymer micelles was observed by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The hydrodynamic diameters of spherical micelles declined gradually with the increase of the hydrophobic chain lengths of the copolymers. The critical micelle concentration (CMC) values were determined from fluorescence emission, and it was found that the CMCs decreased with an increase of PSt hydrophobic block lengths.

• Journal of the Korean Chemical Society
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• v.59 no.5
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• pp.379-386
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• 2015

The solubilization of p-chlorobenzoic acid in aqueous solutions of pure cationic, nonionic, amphoteric, and their mixed surfactant systems have been measured by the UV-Vis spectrophotometric method. The effects of hydrophobic tail-group with different chain length and the hydrophilic head-group on the solubilization of p-chlorobenzoic acid have been studied and also thermodynamic parameters have been calculated from the dependence of K_s values on the temperature. The results show that the values of ΔG^o for the solubilization by all surfactant systems are negative and the values of ΔH^o and ΔS^o are all positive.

• Journal of the Korean Applied Science and Technology
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• v.7 no.1
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• pp.13-24
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• 1990

2-N,N,N-trimethyl ammonia decanoate, 2-N,N,N-trimethyl ammonio dodecanoate, 2-N,N,N-trimethyl ammonia tetradecanoate and 2-N,N,N-hexadecanoate with in straight long chain alkyl carboxybetaines, and N-decyl N,N-dimethyl ammonio ethanoate, N-dodecyl N,N-dimethyl ammonia ethanoate, N-tetradecyl N,N-dimethyl ammonia ethanoate and N-hexadecyl N,N-dimethyl ammonia ethanoate with in nitrogen-straight long chain alkyl carboxy betaines measured respectively surface tensions by the stalagmometer method at various temperature, also their critical micelle concentration were evaluated. In micellization, the contribution of standard free energy change(${\Delta}G^{\circ}m$), standard enthalpy change(${\Delta}H^{\circ}m$) and standard entropy change (${\Delta}S^{\circ}m$), have been calculated, with increasing temperature. ${\Delta}H^{\circ}m$ changes from negative, and a similar change in the sign of ${\Delta}H^{\circ}m$ is observed with increasing chain length at $25^{\circ}C$, while the entropy of micellization, ${\Delta}S^{\circ}m$ is positive over the temperature range studied, it becomes less so at higher temperatures. Estimates of the enthalpy and entropy contribution attributable to the ion head group and alkyl chain have been made. The enthalpy and entropy change, per methylene group increase respectively with increasing chain length the result are discussed in terms of current theories of micellization.

• Journal of the Korean Applied Science and Technology
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• v.17 no.4
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• pp.213-225
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• 2000

Sophorolipids were biosynthesized using a strain of yeast, Torulopsis bombicola ATCC22214. It has been reported that this yeast gives the highest yields for the production of biosurfactant sophorolipids. Hence, this yeast was used in this study. One of the objectives of this study is to increase the yield of the sophorolipid synthesis. To meet this end, basic culture medium was formulated on the basis of literature research to-date. When this medium was used, the increase in yield from 15% to 150% was observed compared to using the media in the literature. To examine how the interfacial characteristics of sophorolipids change with substrate, glucose (the first carbon source) was maintained in the media and after being cultured for three days, the second carbon sources such as alkanes, vegetable oils, alcohols or organic acids were added. The whole broth was extracted twice with ethyl acetate and the extract was analyzed by thin layer chromatograhy(TLC). After qualitative analyses by TLC, surface tensions of sophorolipids were measured by the Wilhelmy plate method and critical micelle concentration(CMC) was determined using these surface tension data. Also, interfacial tensions were measured by the spinning drop method and emulsions of the three-component water/decane/sophorolipid system were tested. Sophorolipids were effective and efficient in terms of surface tension reduction and CMC, but they were ineffective as emulsifiers because emulsions were separated within 30 minutes.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.602-611
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• 2014

The critical micelle concentration (CMC) of the zwitterionic surfactant of dodecyldimethyl(3-sulfopropyl)ammonium hydroxide(LSB, $CH_3(CH_2)_{11}N^+(CH_3)_2(CH_2)_3SO{_3}^-$) and LSB/Tween-20, LSB/Tween-40, LSB/Tween-80 and LSB/DTAB, LSB/TTAB, LSB/CTAB mixed surfactant systems were determined by using the UV/Vis absorbance method from 284 K to 312 K. And the effects of temperature on the micellization have been measured for the thermodynamic study. The results show that the measured values of gibbs free energy are all negative in the whole measured. The values of enthalpy are positive Tween-20, And negative other surfactants. but the values of entropy are positive in the whole measured temperature region. The results show that all of the thermodynamic parameters are dependent on temperature and alkyl-group's length.

• Economic and Environmental Geology
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• v.35 no.5
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• pp.421-428
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• 2002

Lab-scale experiments were conducted to evaluate the effect of surface tension reduction on the extension of the influence zone and the VOC removal efficiency of ground water sparging. A glass column packed with coarse sand was used for VOC removal test at two different surface tensions. A glass column without porous media was also used fer control purpose prior to sand-packed column test. A quasi-two-dimensional glass box model, packed with a sand, was used fer sparging zone tests at different water surface tensions. Surface tension of the aquoues solution used in this study was controlled using sodium dodecyl sulfate (SDS). For the glass, sand column experiments, total amount of air filled in the media increased as surface tension decreased. Toluene (used as VOC in this study) removal rate increased slightly with decreased surface tension f3r both free water column and sand-packed column. Air sparging zone extended up to 500% as the surface tension decreased. Combining the results from two different experiments, VOC removal efficiency is expected to increase significantly with surface tension reduction.

• Applied Chemistry for Engineering
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• v.21 no.3
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• pp.337-342
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• 2010

The interaction of monochlorophenol isomers with the micellar system of TTAB (tetradecyltrimethylammonium bromide) was studied by the UV/Vis spectrophotometric method. The solubilization constants ($K_s$) of monochlorophenol isomers into this micellar system have been measured with the change of temperature. Various thermodynamic parameters (${\Delta}G^{\circ}_s$, ${\Delta}H^{\circ}_s$, and ${\Delta}S^{\circ}_s$) have been calculated and analyzed from the dependence of $K_s$ values on the temperature. The results show that the values of ${\Delta}G^{\circ}_s$ and ${\Delta}H^{\circ}_s$ are all negative but the values of ${\Delta}S^{\circ}_s$ are all positive for the solubilizations of all isomers within the measured temperature range. The effects of additives (n-butanol and NaCl) on the solubilization of monochlorophenol isomers by the same surfactant system have been also measured. There was a great change on the values of $K_s$ and CMC simultaneously with these additives. From these changes we can postulate the solubilization sites of each isomer in the micellar system of TTAB.

• Polymer(Korea)
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• v.30 no.5
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• pp.437-444
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• 2006

Reactive hydroxypropyl methylcellulose phthalate (reactive HPMCP) was synthesized by using a stepwise urethane reaction with isophorone diisocyanate (IPDI) and 2-hydroxyethyl moth acrylate (HEMA). Molecular weight, acid number, and critical micelle concentration (CMC) of the synthesized reactive HPMCP and pristine HPMCP were measured and used as a polymeric surfactant in the emulsion polymerizations of styrene. In the preparation of HPMCP-hybrid poly styrene nanoparticles, 6, 9, 12, 18, and 24 wt% of HPMCPs were introduced, and the maximum rate of polymerization ($R_{p,max}$), the average number of radicals per particle (n), particle size distribution were investigated. In addition, core - shell morphology of the nanoparticles were observed by using TEM and their thermal stabilities were measured by using TGA. Reactive HPMCP showed higher $R_{p,max}$, smaller particle size, larger values of n and gel contents as compared with pristine HPMCP, due to the vinyl groups from HEMA, which can be reacted with styrene oligomers, in the reactive HPMCP.