• Applied Chemistry for Engineering
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• v.20 no.5
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• pp.479-485
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• 2009

In this study, basic physical properties were measured for ASCO EQ85 cationic surfactant of triethanolamine-ester quaternary ammonium salt and effect of pH on softening performance on fabrics was investigated using zeta potential measurement and adsorption experiment by quartz crystal microbalance. The CMC of the surfactant was near $3{\times}10^{-3}mol/L$ and the surface tension at CMC was about 40 mN/m. The interfacial tension measurement between 1 wt% aqueous solution and n-dodecane measured by spinning drop tensiometer showed that interfacial tension slightly increased with an increase in pH but the equilibration time was not affected by pH. The surfactant adsorption was found to increase with an increase in surfactant concentration and was also affected by pH of surfactant solution. The friction factor for fabrics treated with ASCO EQ85 surfactant was shown to increase with pH and better softening effect was found under acidic conditions. Half-life for foams generated with ASCO EQ85 surfactant solution increased with pH, which indicated an increase in foam stability with pH.

• Journal of Adhesion and Interface
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• v.24 no.3
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• pp.77-85
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• 2023

In this research, polymeric anionic surfactants having various molecular weights and acid values were synthesized using a continuous stirred tank reactor (CSTR). The CSTR has an advantage of higher production rate and more constant product properties compared to batch and semi-batch reactors. The polymeric surfactants were made using butyl acrylate as a hydrophobic group and acrylic acid as a hydrophilic group. The synthesized polymeric surfactants were ionized with alkali solution and were used as an anionic surfactant. To investigate the properties as a surfactant, the properties of the synthesized surfactant, such as acid value, critical micelle concentration (CMC) and molecular weight, were measured. The results showed that the acid values of the polymeric surfactants were 60 to 380 and a number average molecular weight were 8,000 to 13,000 g/mol. Also, it was found that the CMC was around 0.01 g/ml, which showed similar level values with ordinary surfactant. To prove the performance of the polymeric surfactant, acrylic emulsion PSAs were synthesized using the acquired polymeric surfactant. The results showed that the maximum peel strength of 21.24 N/25mm when acid value was 150 and molecular weight was 8,500 g/mol. The values of peel strength and initial tack of acrylic emulsion PSAs using polymeric surfactant synthesized in this study showed much higher than those of reference PSAs synthesized using ordinary anionic surfactant, SDS (Sodium Dodecyl Sulfate) and SDS/TRX (Triton X-100).

• Clean Technology
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• v.24 no.3
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• pp.206-211
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• 2018

Lead molybdate ($PbMoO_4$) were successfully synthesized using a facile surfactant-assisted hydrothermal process and characterized by XRD, Raman, PL, BET and DRS. We also investigated the photocatalytic activity of these materials for the decomposition of Rhodamine B under UV-light irradiation. From XRD and Raman results, well-crystallized $PbMoO_4$ crystals have been successfully synthesized with a facile surfactant-assisted hydrothermal process and had 52-69 nm particle size. The $PbMoO_4$ catalysts prepared at $160^{\circ}C$ showed the highest photocatalytic activity. The PL peak was appeared at about 540 nm at all catalysts and it was also shown that the excitonic PL signal was proportional to the photocatalytic activity for the decomposition of Rhodamine B.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.26 no.1
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• pp.213-232
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• 2000

Cetostearyl alcohol has been incorporated into cosmetic or pharmaceutial emulsions to give them an appropriate consistency and a long term stability. It is well known that cetostearyl alcohol forms a gel phase with a nonionic surfactant in an aqueous system, and the properties of the gel phase depend on several factors such as the ratio of fatty alcohols. The aim of the present Paper is to investigate the effect of the structural difference of the lipophilic part of surfactants on the stability of the gel phase in the nonionic surfactant / cetostearyl alcohol / water ternary systems using differential scanning calorimeter. It is concluded that the gel phase formed by the surfactant having the bended alkyl chain is more unstable than that formed by the case of the straight alkyl chain, and we discussed the reason why the former is more unstable after long term storage by means of the measurements of the ${\Delta}$H.

• Journal of the Korean Chemical Society
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• v.59 no.5
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• pp.407-412
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• 2015

A preconcentration procedure for determination of palladium by laser thermal lens spectrometry (TLS) is proposed. It is based on cloud point extraction of palladium(II) ions as 2-(3,5-dichloro-2-pyridylazo)-5-dimethylaminoaniline (3,5-diCl-PADMA) complexes using octylphenoxypolyethoxyethanol (Triton X-114) as surfactant. The effects of various experimental conditions such as pH, concentration of ligand and surfactant, equilibration temperature and time on cloud point extraction were studied. Under the optimized conditions, the calibration graph was linear in the range of 0.15~6 ng mL⁻¹, and the detection limit was 0.04 ng mL⁻¹ with an enrichment factor of 22. The sensitivity was enhanced by 846 times when compared with the conventional spectrophotometric method. The recovery of palladium was in the range of 96.6%~104.0%. The proposed method was applied to the determination of palladium in water samples.

• Journal of Applied Biological Chemistry
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• v.52 no.4
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• pp.195-199
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• 2009

To select antifungal surfactants, control efficacy of various nonionic and anionic surfactants on cucumber powdery mildew was evaluated under greenhouse conditions. Among 14 surfactants, pentaetylene glycol monododecyl ether ($C_{12}E_5$), mixture of heptaethylene glycol monodecyl ether and heptaethylene monododecyl ether, and heptaethylene glycol mono-9-octadecenyl ether effectively reduced the development of powdery mildew on cucumber plants. Among the surfactants, $C_{12}E_5$ gave the best control efficacy on the disease and did not show phytotoxic response in cucumber plants. Whereas, fenarimol at a recommended rate (31.3 mg/L) showed less control activity than the surfactant (1,000 mg/L). In addition, mixtures of the surfactant and DBEDC, a protective fungicide, showed high control efficacies against powdery mildews of cucumber and strawberry by additive effect in greenhouse tests.

• Journal of Electrochemical Science and Technology
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• v.11 no.2
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• pp.148-154
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• 2020

Highly ordered mesoporous manganese oxide films were electrodeposited onto indium tin oxide coated (ITO) glass using sodium dodecyl sulfate (SDS) and ethylene glycol (EG) which were used as a templating agent and stabilizer for the formation of micelle, respectively. The manganese oxide films synthesized with surfactant templating exhibited a highly mesoporous structure with a long-range order, which was confirmed by SAXRD and TEM analysis. The unique porous structure offers a more favorable diffusion pathway for electrolyte transportation and excellent ionic conductivity. Among the synthesized samples, Mn₂O₃-SDS+EG exhibited the best electrochemical performance for a supercapacitor in the wide range of scan rate, which was attributed to the well-developed mesoporous structure. The Mn₂O₃ prepared with SDS and EG displayed an outstanding capacitance of 72.04 F g^-1, which outperform non-porous Mn₂O₃ (32.13 F g^-1) at a scan rate of 10 mV s^-1.

• Applied Chemistry for Engineering
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• v.20 no.5
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• pp.493-499
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• 2009

The properties of polystyrene and styrenic copolymer nanocomposites containing carbon nanotubes (CNT) and nanoclays were studied. Polystyrene and styrenic copolymer containing styrene and vinylbenzyl trimethylammonium chloride (SVTAC) were synthesized by emulsion polymerization. Polystyrene/CNT/clay and SVTAC/CNT/clay nanocomposites with various concentrations of CNT and different types of clay were prepared via mixing of polystyrene emulsion and clay. SVTAC/CNT nanocomposites showed a better electrical conductivity than PS/CNT nanocomposites. Nanocomposites with more surfactant during polymerization showed a better electrical conductivity than the ones with less surfactant. These indicated the positive effect of comonomer and surfactant on the electrical conductivity. Transmission electron microscopy (TEM) was used to analyze the state of CNT dispersion. TEM results showed that CNT loading, comonomer composition and amount of surfactant affected the final dispersion of CNT in nanocomposites. In order to confirm the effects of CNT loading, comonomer composition and the amount of surfactant on the thermal and dynamic mechanical properties, DSC and DMA analyses were conducted.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.455-463
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• 2012

In this study, the measurement of physical properties of ethylene oxide-propylene oxide adducted zwitterionic surfactants were measured such as critical micelle concentration, surface tension, interfacial tension, contact angle, viscosity and foam stability. Also, the dual function characteristics of a zwitterionic surfactant were investigated by determining an isoelectric point, which were obtained using zeta potential measurement and QCM (quartz crystal microbalance) experiments. The isoelectric point of DEP-OSA82-AO zwitterionic surfactant determined by zeta potential measurement was close to that obtained by QCM experiment and both results have shown almost the same trend as that determined by the frictional property measured using an automated mildness tester. In particular, it has been observed that DEP32-OSA82-AO and DEP34-OSA82-AO surfactants provide better softening effect at a pH of acidic or neutral condition than at an alkaline condition. This result indicates that both surfactants act as a cationic surfactant at a pH of acidic or neutral condition and thus provide good softening effect during a rinsing cycle in the detergency process.

• Korea-Australia Rheology Journal
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• v.14 no.4
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• pp.189-201
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• 2002

The interaction between hydrophobically modified hydroxyethyl cellulose (hmHEC), containing approximately 1 wt% side-alkyl chains of $C_{16}$, and an anionic sodium dodecyl sulphate (SDS) surfactant was investigated. For a semi-dilute solution of 0.5 wt% hmHEC, the previously observed behaviour of a maximum in solution viscosity at intermediate SDS concentrations, followed by a drop at higher SDS concentrations, until above the cmc of surfactant when the solution resembles that of the unsubstituted polymer, was confirmed. Additionally, a two-phase region containing a hydrogel phase and a water-like supernatant was found at low SDS concentrations up to 0.2 wt%, a concentration which is akin to the critical association concentration, cac, of SDS in the presence of hmHEC. Above this concentration, SDS molecules bind strongly to form mixed micellar aggregates with the polymer alkyl side-chains, thus strengthening the network junctions, resulting in the observed increase in viscosity and elastic modulus of the solution. The shear behaviour of this polymer-surfactant complex during steady and step stress experiments was examined In great detail. Between SDS concentrations of 0.2 and 0.25 wt%, the shear viscosity of the hmHEC-polymer complex network undergoes shear-induced thickening, followed by a two-stage shear-induced fracture or break-up of the network. The thickening is thought to be due to structural rearrangement, causing the network of flexible polymers to expand, enabling some polymer hydrophobic groups to be converted from intra- to inter-chain associations. At higher applied stress, a partial local break-up of the network occurs, while at even higher stress, above the critical or network yield stress, a complete fracture of the network into small microgel-like units, Is believed to occur. This second network rupture is progressive with time of shear and no steady state in viscosity was observed even after 300 s. The structure which was reformed after the cessation of shear is found to be significantly different from the original state.