• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2000년도 추계종합학술대회
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• pp.653-655
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• 2000

Alumina-surfactant mesostructures have been synthesized with the $Al_{13}$-Keggin cation prepared by Al(N $O_3$)$_3$.9$H_2O$ solution with NaOH solution in the presence of a non-ionic surfactant at room temperature. The synthesized samples had the hexagonal structure similar to MCM-41 type materials. These samples have been characterized by X-ray diffraction and thermal analysis(TG). The samples prepared from OH/Al ratio 1.5 and 2.0 were well-crystalline mesostructures, but the sample from OH/Al ratio 2.5 was not. Also, The d$_{100}$ value decreased slightly from 38 to 36 according to the OH/Al mole ratio. These results could be explained that Keggin ion depended on the OH/Al molar ratio and pHpH

• 한국물환경학회지
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• 제23권6호
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• pp.966-972
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• 2007

A novel organoclay has been developed with aluminium-pillared clay modified with an amphoteric surfactant, N-Dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (DDAPS). This novel organoclay is expected to have phosphorus removal capacity as well as organic and inorganic contaminant removal capacity, due to aluminum inside the clay structure. It also exhibited less surfactant desorption than conventional cation surfactant-based organoclays. Phosphorus in water can be decreased from 0.2 mg/L to 0.0012 mg/L in 27 hours with this organoclay. Also, cadmium could removed from water using this proposed organo-clay. Experiments were performed under various pHs and amphoteric surfactants sorption capability was the highest at pH 5 when more of the amphoteric surfactant head group took on positive charges.

• 한국세라믹학회지
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• 제28권2호
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• pp.146-152
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• 1991

Ultra fine and homogeneous (Ni0.4Zn0.6)Fe2O4 ferrite powders were prepared by direct-wet, Hydrothermal and coprecipitation methods. In case that specific surface areas of Ni-Zn ferrite powders were over 220㎡/g, 100㎡/g, 30㎡/g individually direct-wet, hydrothermal and coprecipitation methods. The Ni-Zn ferrite magnetic fluids of which Solvents were benzene or kerosene was prepared by making cation surfactant adsorbed on the surface of the (Ni0.4Zn0.6)Fe2O4. The results that measured dispersion and viscosity by making cation surfactant adsorbed were as follows. 1. The adsorption amount of Oleric acid be proportioned the specific surface area of powders. 2. The maximum amount of Oleric acid was 36wt% of dried powders which has 220㎡/g of specific surface area. 3. The stability of fluid by direct-wet synthesis emthod in benzene or kerosene solvent excellent.

• Bulletin of the Korean Chemical Society
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• 제12권5호
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• pp.474-477
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• 1991

The preferential transport phenomena of neutral cation-anion moieties in neutral macrocycle-facilitated emulsion liquid membrane were described in this study. Emulsion membrane systems consisting of (1) aqueous source phase containing 0.001 M M($NO_3$)$_2(M=Mn^{2+},\;Co^{2+},\;Ni^{2+},\;Cu^{2+},\;Zn^{2+},\;Sr^{2+},\;Cd^{2+},\;and\;Pb^{2+})$ (2) a toluene membrane containing 0.01 M ligand $(DBN_3O_2$, DA18C6, DT18C6, TT18C6, HT18C6) and the surfactant span 80 (sorbitan monooleate) (3% v/v) and (3) an aqueous receiving phase containing $Na_2S_2O_3$ or $NaNO_3$ were studied with respect to the disappearence of transition metal ions from the source phase as a function of time. Cation transports for various two component or three component equimolar mixture of transition metal and $Cu^{2+}$ in a emulsion membrane system incorporating macrocyclic ligand (HT18C6) as carrier were determinded. $Cu^{2+}$ was transported higher rates than the other $M^{2+}$ in the mixture solution. Equilibrium constants for cation-source phase co-anion, cation macrocycle and cation-receiving phase reagent interaction are examined as parameters for the prediction of cation transport selectivities.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 가을 학술발표회 논문집
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• pp.241-246
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• 1999

In this research, electrokinetic remediation test was experimented with contaminated kaoline specimen at below, above the cation-exchange capacity of the mineral. The changes of the flow in electro-osmosis with open electrodes and current were presented, and lead removal results were evaluated through the extraction test. As a result, it was showed that removal efficiency was 20-30%, 67-87% In the anode As lead transport continues, the lead precipitation within a narrow zone very close to the cathode can go significantly high. This high lead precipitation near the cathode could block the flow path, decrease the conductivity, and thus the electroosmotic flow. The net effect will cause a decrease in the efficiency of electrokinetic processing. Therefore, in this study, citric acid and surfactant solution was used at the cathode as enhancement techniques.

• Bulletin of the Korean Chemical Society
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• 제10권5호
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• pp.437-442
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• 1989

The cmc's of sodium dodecyl sulfate (SDS)/Triton X-100 surfactant mixtures were determined by surface tension measurement at various surfactant compositions. The cmc values were lower than those predicted from ideal mixture. The regular solution theory was applied to calculate the interaction parameter, micellar composition, and the activity coefficients of surfactants in the mixed micelle. The interaction parameter (${\beta}$) was - 2.1. The nonideality arised largely from decreased activity of SDS in the mixed micelle. The mean aggregation numbers (${\bar{n}}$) and micropolarity of hydrocarbon region of the mixed micelles were determined by luminescence probe techniques. The total aggregation number (${\bar{n}}_{SDS}+{\bar{n}}_{TX}$) in mixed micelles showed little dependency on the composition of the micelle. The apparent dielectric constant of the hydrocarbon region of the micelle vs micellar composition plot showed positive deviation from linearity. Emission and emission quenching of excited tris(2,2'-bipyridine)ruthenium(Ⅱ) cation, $(Ru(bpy)_3^{2+})$, by methylviologen ($MV^{2+}$) were also investigated in the mixed micellar solutions. The quenching rate was lowest when the mole fraction of SDS in the surfactant mixtures (${\alpha}_{SDS}$) is about 0.25 and highest at ${\alpha}_{SDS}$ = 0.85. This was explained in terms of combined effects of binding of the cations with the micelle and mobility of the bound cations on the surface of the micelles.

• 한국산학기술학회논문지
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• 제14권5호
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• pp.2544-2549
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• 2013

고성능 고분자/클레이 나노 복합재료의 제조 과정에는 친수성을 보이는 클레이 원료 물질인 $Na^+$-MMT (sodium monmorilonite)를 친유성을 갖도록 유기화된 계면활성제로처리하여 개질하는 과정이 필수적이다. 이를 위하여 이 연구에서는 VDAC (vinylbenzyldimethyl-dodecylammonium chloride)를 간단한 화합물로부터 합성하였고 이를 이용하여 양이온 교환반응에 의하여 $Na^+$-MMT를 개질한 후 $VDA^+$-MMT를 제조하였다. 이를 스티렌과 혼합하여 in-situ 중합에 의하여 나노복합재료를 제조하였고 클레이의 분산성 및 차단특성을 연구하였다. 연구 결과 PS/$VDA^+$-MMT 나노 복합재료의 경우 클레이의 분산이 $Na^+$-MMT와 비교할 때 현저히 증가함을 확인하였고 이로 인해 유기 용매에 대한 차단 특성이 매우 우수함을 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제24권1호
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• pp.37-44
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• 2003

We examined the effect of polyether-type nonionic surfactants (Brij 35, Triton X-100, Tween 20 and Tween 80) on the potentiometric properties of sodium-, potassium- and calcium-selective membranes which are prepared with widely used ionophores and four kinds of polymer matrices [poly(vinyl chloride) (PVC), polyurethane (PU), PVC/PU blend, and silicone rubber (SR)]. It was found that the PVC-based membranes, which provide the best performance among all other matrix-based membranes in the absence of nonionic surfactants, exhibited larger change in their potentiometric properties when nonionic surfactants are added to the sample solution. On the other hand, the sodium-selective SR-based membrane with calix[4]arene, potassium-selective PVC/PU- or SR-based membrane with valinomycin, and the calcium-selective SR-based membrane with ETH 1001 provide almost identical analytical performance in the presence and absence of Tween 20 or Tween 80 surfactants. The origin of nonionic surfactants effect was also investigated by interpreting the experimental results obtained with various matrices and ionophores. The results suggest that the nonionic surfactant extracted into the membrane phase unselectively form complexes with the primary and interfering ions, resulting in increased background potential and lower binding ability for the ionophore. Such effects should result in deteriorated detection limits, reduced response slopes and lower selectivity for the primary ions.

• Macromolecular Research
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• 제15권1호
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• pp.51-58
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• 2007

The approach studied in the present work produced an exfoliated state of clay layers via confinement of the charged nano-sized polystyrene (PS) beads within the gallery of swollen pristine clay. It was demonstrated that adsorption of the polymer nanobeads dramatically promotes expansion of the clay gallery. A comparative study of incorporation was conducted by employing organo-modified clay along with two different colloid polymer systems: electrostatically stabilized PS nanobeads and cationic monomer-grafted PS nanobeads. The mechanism of adsorption of the monomer-grafted polymer beads onto clay via cationic exchange between the alkyl ammonium group of the polymer nanobeads and the interlayer sodium cation of the layered silicate was verified by using several techniques. As distinct from the polymer nanobeads formed using conventional miniemulsion polymerization method, competitive adsorption of stabilizing surfactant molecules was be prevented by grafting the surface functional groups into the polymer chain, thereby supporting the observed effective adsorption of the polymer beads. The presence of surface functional groups that support the establishment of strong polymer-clay interactions was suggested to improve the compatibility of the clay with the polymer matrix and eventually play a crucial role in the performance of the final nanocomposites.

• 대한토목학회논문집
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• 제26권6B호
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• pp.677-682
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• 2006

본 연구에서는 이보다 더 성능이 향상된 유기 벤토나이트의 제작을 위해 Hexadecyltrimethylammonium(HDTMA)보다 흡착능력이 더 좋을 것으로 예상 되어지는 양이온성 계면 활성제인 Dodecyldimethylethylammonium(DDDEA)와 금속 이온을 유기 벤토나이트 합성 시 동시에 첨가하여 합성방법에 대한 비교와 인 제거 성능을 비교해 보았다. 다양한 유기 벤토나이트의 제조 방법으로 실험해본 결과 금속 이온을 이용하여 층간 가교 점토를 합성한 후 DDDEA 계면 활성제 용액을 첨가하여 합성한 유기 벤토나이트가 계면활성제의 흡착이 가장 좋은 흡착 능력을 보였고 따라서 오염 물질 제거해도 효율 적일 것이라는 예상을 할 수 있었다. 또한 인의 제거 실험에서도 금속이온 층간 가교 점토에 계면 활성제 용액을 첨가하여 합성한 유기 벤토나이트가 약 81%의 가장 높은 인 제거 효율을 보여 주었다. 결과적으로 알루미늄 금속의 첨가를 통해 계면활성제의 흡착이 기존의 HDTMA 유기 벤토나이트보다 더 많이 일어나게 되어 유기 오염 물질의 제거가 잘 이루어질 것으로 예상 되었고 인의 제거도 잘 이루어 졌지만 탈착 실험에서는 금속 이온으로 인하여 계면활성제의 탈착 또한 잘 일어나게 되었다.