• 자원환경지질
• /
• 제35권2호
• /
• pp.149-154
• /
• 2002

오염된 토양의 복원에서 계면 활성제 용액의 조건에 따른 영향을 조사하기 위하여 주상실험이 실행되었다. 계면 활성제 용액의 조건에는 농도와 pH가 선택되었으며 모델 소수성 유기화합물은 삼염화벤젠, 그리고 DOSL라 OPEE 계면활성제가 본 연구에 사용 되었다. 또한 미국의 아이오와 토양이 본 연구에 이용 되었다. 실험 결과, 계면활성제 용액의 최적 조건은 농도 4%(v/v), pH 10 이며, 이러한 최적 조건이 적용될 때 93-98%의 삼염화벤젠이 오염된 토양으로부터 회수되었다. 규명된 최적 조건은 게면 활성제를 이용하여 삼염화벤젠으로 오염된 토양 복원에 유용하게 사용 될 수 있다.

• 한국응용과학기술학회지
• /
• 제26권4호
• /
• pp.422-427
• /
• 2009

We have investigated the effects of polyols and NaCl on the rheological behaviours of surfactant mixtures. Sodium lauryl ether sulfate (SLES), cocamidopropyl betaine (CAPB), disodium cocoamphodiacetate (DSCA), cocamide DEA (CDEA) and lauroyl/myristoyl DEA (LMDE) were used as surfactants. The polyols added into the surfactant mixture were 1,3-butylene glycol, propylene glycol, glycerin, sorbitol, dipropylene glycol, PEG 1500 and PEG 400. The addition of amphoteric surfactant to SLES aqueous solution lead to increase the height of foam and the viscosity of the system. The addition of nonionic surfactant, LMDE or CDEA to the SLES aqueous solution increased the viscosity and the effect of LMDE was better than that of CDEA. The effect of adding polyols and NaCl into the surfactant mixture aqueous solution lead to increase or decrease the viscosity of the systems depending on the concentration of NaCl and the kinds of polyols. These results can be explained through the salting in or salting out of surfactant of the systems.

• Journal of Pharmaceutical Investigation
• /
• 제34권3호
• /
• pp.185-192
• /
• 2004

The objective of this study was to evaluate the effects of surfactant type and concentration upon dissolution rates of carbamazepine from an immediate-release tablet. The dissolution media used in this study were aqueous solutions containing 0.1-2% sodium lauryl sulfate, cetyltrimethylammonium bromide, or polysorbate 80. The solubility of carbamazepine in the dissolution media was determined at first. A dissolution study was then conducted by using the USP dissolution apparatus II (paddle method) with an agitation rate of 75 rpm. Aliquots of the dissolution media were taken at predetermined time intervals, and the amount of carbamazepine dissolved was measured spectrophotometrically at 285 nm. The dissolution data obtained were fitted into a biphasic exponential equation with four parameters. Excellent correlations were observed between the experimental data and the theoretical ones predicted by the equation. This equation permitted the calculation of $T_{50%}$ (the time required for dissolving 50% of carbamazepine) under various experimental conditions. Differentiation of the equation also led to the attainment of dissolution rates at dissolution time points. The addition of a surfactant to an aqueous solution led to increasing the solubility of carbamazepine by 3- to 12-folds, depending upon its type and concentration. This event also resulted in enhancing the magnitude of a sink condition during the dissolution study. As a result, the dissolution rate of carbamazepine was affected by the aqueous surfactant concentration in a proportional manner. Subsequently, $T_{50%}$ values declined rapidly, as the surfactant concentration increased. Such effects were observed in decreasing order of sodium lauryl sulfate, cetyltirmethylammonium bromide, and polysorbate 80. These results clearly demonstrated that it was possible to tailor a dissolution rate and $T_{50%}$ of carbamazepine by manipulating the type and concentration of a surfactant. Relevant information would be beneficial to setting up dissolution specifications for poorly water-soluble drug products.

• Journal of Microbiology and Biotechnology
• /
• 제18권9호
• /
• pp.1564-1571
• /
• 2008

We investigated whether the threshold concentration for polychlorinated biphenyl (PCB) dechlorination may be lower in biosurfactant-amended sediments compared with biosurfactant-free samples. At PCB concentrations of 40, 60, and 120 ppm, the surfactant amendment enhanced the PCB dechlorination rate at all concentrations and the rate was also faster at higher concentrations. On a congener group basis, dechlorination proceeded largely with group A (congeners with low threshold) in both surfactant-free and -amended sediments, accumulating mainly group C (residual products of dechlorination) congeners, and surfactant enhanced the dechlorination rate of group A congeners. Since the PCB threshold concentration for the inoculum in the experiment was lower than 40 ppm, we carried out another experiment using sediments with lower PCB concentrations, 10, 20, and 30 ppm. Sediments with 100 ppm were also performed to measure dechlorination at a PCB saturation concentration. Comparison between the plateaus exhibited that the extent of dechlorination below 40 ppm PCBs was much lower than that at a saturation concentration of 100 ppm. There was no significant difference in the extent of dechlorination between surfactant-free and -amended sediments. Moreover, surfactant did not change the congener specificity or broaden the congener spectrum for dechlorination at PCB concentrations below 40 ppm. Taken together, it seems that at a given PCB concentration, dechlorination characteristics of dechlorinating populations may be determined by not only the congener specificity of the microorganisms but also the affinity of dechlorinating enzyme(s) to individual PCB congeners.

• 한국분말재료학회지
• /
• 제16권2호
• /
• pp.131-137
• /
• 2009

This paper deals with the effects of the surfactant and preplate process (sensitization and activation) on electroless copper plating on carbon nano-fiber (CNF). Ultrasonic irradiation was applied both during dispersion of CNF and during electroless plating containing preplate process. The dispersion of CNF and flatness of the plated copper film were discussed based on the changes in surfactant concentration and preplate process time. It was clearly shown that high concentration of surfactant and long time of preplate process could promote the agglomeration of CNF and uneven copper plating on CNF.

• 한국의류산업학회지
• /
• 제11권3호
• /
• pp.465-468
• /
• 2009

In this study, acid cellulase was used to treat denim fabrics by varying pH, temperature, enzyme concentration, treatment time and non-ionic surfactant (Triton X-100) concentration. Treatment condition was controlled based on the weight loss. The characteristics of enzyme-treated fabrics were measured in terms of tearing strength, stiffness, and color difference. The optimum conditions for cellulase treatment of denim fabric were pH 5.0, $50^{\circ}C$, 3% (o.w.f.), 90minutes. The weight loss did not change significantly with the addition of a non-ionic surfactant, but it improved when more non-ionic surfactant were used. The tearing strength of enzyme-treated denim fabrics did not deteriorate. The stiffness of the treated fabrics improved with the enzymatic treatment with and without the non-ionic surfactant. The difference in color of fabrics treated with enzyme increased.

• 한국환경과학회지
• /
• 제19권5호
• /
• pp.549-563
• /
• 2010

The environmental behaviors of polycyclic aromatic hydrocarbons (PAHs) are mainly governed by their solubility and partitioning properties on soil media in a subsurface system. In surfactant-enhanced remediation (SER) systems, surfactant plays a critical role in remediation. In this study, sorptive behaviors and partitioning of naphthalene in soils in the presence of surfactants were investigated. Silica and kaolin with low organic carbon contents and a natural soil with relatively higher organic carbon content were used as model sorbents. A nonionic surfactant, Triton X-100, was used to enhance dissolution of naphthalene. Sorption kinetics of naphthalene onto silica, kaolin and natural soil were investigated and analyzed using several kinetic models. The two compartment first-order kinetic model (TCFOKM) was fitted better than the other models. From the results of TCFOKM, the fast sorption coefficient of naphthalene ($k_1$) was in the order of silica > kaolin > natural soil, whereas the slow sorbing fraction ($k_2$) was in the reverse order. Sorption isotherms of naphthalene were linear with organic carbon content ($f_{oc}$) in soils, while those of Triton X-100 were nonlinear and correlated with CEC and BET surface area. Sorption of Triton X-100 was higher than that of naphthalene in all soils. The effectiveness of a SER system depends on the distribution coefficient ($K_D$) of naphthalene between mobile and immobile phases. In surfactant-sorbed soils, naphthalene was adsorbed onto the soil surface and also partitioned onto the sorbed surfactant. The partition coefficient ($K_D$) of naphthalene increased with surfactant concentration. However, the $K_D$ decreased as the surfactant concentration increased above CMC in all soils. This indicates that naphthalene was partitioned competitively onto both sorbed surfactants (immobile phase) and micelles (mobile phase). For the mineral soils such as silica and kaolin, naphthalene removal by mobile phase would be better than that by immobile phase because the distribution of naphthalene onto the micelles ($K_{mic}$) increased with the nonionic surfactant concentration (Triton X-100). For the natural soil with relatively higher organic carbon content, however, the naphthalene removal by immobile phase would be better than that by mobile phase, because a high amount of Triton X-100 could be sorbed onto the natural soil and the sorbed surfactant also could sorb the relatively higher amount of naphthalene.

• 한국자원식물학회지
• /
• 제30권6호
• /
• pp.686-692
• /
• 2017

The aim of this study was to determine the suitability of surfactant to extract higher phenolic compound, flavonoid and antioxidant activity from Tartary buckwheat and evaluate the potentiality of surfactant as a screening agent for breeding purpose. Primarily, we employed two types of surfactant (Hydrophilic: Tween 20 and Lipophilic: Span 80) to select the suitable surfactant agent for the extraction of optimum bioactive compounds. Between two surfactants, Tween 20 showed highest efficiency at 4 mM concentration to extract total phenolic content (TP), total flavonoid (TF) and antioxidant activity (AA). Tween 20 at 4 mM concentration was fixed for further analysis along with hot water ($90^{\circ}C$) treatment as a control. In our findings, highest TP (118 mg/g), TF (38 mg/g) and AA (76%) was achieved in KW21 and KW22 among the fifteen accessions of Tartary buckwheat. In other way, TP, TF and AA was 200%, 120% and 110% higher in surfactant formulation compared with control treatment, respectively.

• Journal of Pharmaceutical Investigation
• /
• 제28권4호
• /
• pp.249-255
• /
• 1998

Solid Lipid Nanoparticle(SLN), one of the colloidal carrier systems, has many advantages such as good biocompatibility, low toxicity and stability. In this paper, the effects of drug lipophilicity and surfactant on the drug loading capacity, particle size and drug release profile were examined. SLNs were prepared by homogenization of melted lipid dispersed in an aqueous surfactant solution. Ketoprofen, ibuprofen and pranoprofen were used as model drugs and tweens and poloxamers were tested for the effect of surfactant. Mean particle size of prepared SLNs was ranged from 100 to 150nm. The drug loading capacity was improved with the most lipophilic drug and low concentration of surfactant. Particle size and polydispersity of SLNs were changed according to the used lipid and surfactant. The rates of drug release were controlled by the loading drug and surfactant concentration. SLN system with effective drug loading efficiency and proper particle size for the intravenous or oral formulation can be prepared by selecting optimum drug and surfactant.

• 한국응용과학기술학회지
• /
• 제25권1호
• /
• pp.23-31
• /
• 2008

In general, anionic and cationic surfactants are incompatible because their mixtures form insoluble complexes. There are, however, some complexes that are soluble and behave like regular surfactants, specifically like nonionic surfactants, thus named pseudo-nonionic surfactant complexes. Pseudo-nonionic complexes are more effective and efficient than their ionic surfactant components as shown by their equilibrium and dynamic surface tensions and interfacial tensions. They pack at the interface more than their ionic components. Since, pseudo-nonionic complexes show their own characteristics, they can be treated as separate classes of surfactants distinct from ionic and nonionic surfactants. Novel cationic surfactant was synthesized, having the polyhydroxyl group at the head group. We found that aqueous mixtures of our cationic surfactant and usual anionic surfactant(SDS) could form homogeneous solutions even at high concentration. The properties of mixed surfactant solutions were measured. Foam stability, CMC(critical micelle concentration), water hardness tolerance and thickening effect were tested. The foam stability of mixed surfactants was very good and various synergy effects were observed.