• Polymer(Korea)
• /
• v.36 no.5
• /
• pp.579-585
• /
• 2012

Polystyrene/carbon nanotube (CNT) microcellular foams were prepared to have electrically conductive properties via high internal phase emulsion polymerization. In this study, we have investigated the effects of surface modification of CNT, surfactant content and dispersion time to improve the stability of emulsion and the electrical conductivity of foam. Acid treatment and a surfactant were used to effectively disperse CNTs in the aqueous phase. In the organic phase, CNTs were used after a surface modification with organic functional groups. The degree of dispersion of CNTs was estimated by the electrical conductivity of resultant microcellular foams. With raw CNTs dispersed with the surfactant in the aqueous phase, substantial conductivity increase was observed but the foams were slightly shrunk. The foams prepared with organically modified CNTs dispersed in the organic phase showed stable cell morphology without shrinkage, but displayed limitation to improve the conductivity.

• Journal of Environmental Health Sciences
• /
• v.23 no.3
• /
• pp.109-120
• /
• 1997

The purpose of this study is to evaluate the effectiveness of wastewater treatment containing surfactant. For that, comparative analysis of effectiveness of Featon Oxidation, Aluminum Sulfate, PAC (Poly Aluminum Chloride) on the treatment of the synthetic wastewater containing LAS (Linear Alkyl Sulfate), a main component of the commercial detergent was carried. Then, the optimum pH, the dosage of reagents, and the concentration of the LAS in each treatment were determined. The results of the study were summarized as following. 1. In Fenton Oxidation, optimal pH was 3 and 97.92% removal of LAS was achieved. However, the increase of the pH reduced the efficiency of LAS removal. The proper chemical dosages of FeSO$_4$ and $H_2O_2$ were 300 mg/l and the increase of dosages didn't affected the removal efficiency. Therefore, it was concluded that the economic chemical dosage was 300 mg/l of FeSO$_4$ and $H_2O_2$. 2. In case of Alum treatment, optimal pH was 11 with 61.13% removal efficiency. At other pH range, the removal efficiency was very low indicating that removal efficiency is greatly influenced by pH. The proper chemical dosage was 200 mg/l with the removal efficiency of 77.65%. The increase of chemical dosage, however, reduced the removal efficiency. 3. In case of using PAC, optimal pH was 6 with 97.99% removal efficiency. The result showed that wastewaters containing surfactant were almost completely removed at pH 6 by PAC. Removal efficiency was decreased by increasing PAC dosage higher than 400 mg/l and dosage over 700 mg/l of PAC abolished the treatment. 4. The comparative analysis of three methods revealed that the effective pH ranges were at pH 2-5 with Fenton oxidation, at pH 6-11 with PAC, and pH 11 with Alum. The removal efficiencies at these pH were 83.95-97.92%, 75.98-97.99% and 61.13%, respectively. 5. Increase in LAS concentration reduced the removal efficiencies of all three methods. In the case of PAC or Alum treatment, treatment abolished at LAS concentration higher than 700 mg/l.

• Journal of the Korean Geotechnical Society
• /
• v.15 no.2
• /
• pp.153-164
• /
• 1999

The solubilization of BTEX was evaluated in aqueous surfactant solutions with and without several additives. Anionic surfactant(Sodium Dodecyl Sulfate, SDS) and nonionic surfactants (NEODOL(equation omitted)25-3 and $SOFTANOL\circledR-90$ were used as test surfactants. The effects of surfactant HLB(Hydrophile-Lipophile Balance) Number and hydrocarbon molar volume and polarity of BTEX on the MSR(Molar Solubilization Ratio), micelle-water partition coefficient of BTEX, and CMC(C,itical Micelle Concentration) were investigated. Optimizing treatment conditions applicable to enhanced solubilization was also studied by manupulating salinity or electrolyte control with additives of ethyl alcohol, hydrotrope, and electrolyte solution. The most effective surfactant for solubilization was found $SOFTANOL\circledR-90$, since HLB number of 13.6 is similar to those values of BTEX ranging between 11.4 and 12.2, which was also proved experimentally. Ethyl alchohol of 3% was the most effective additives in reducing CMC and improving solubilization among the conditions using SDS, NEODOL(equation omitted)25-3, and $SOFTANOL\circledR-90$ with three additives. The partitioning of BTEX between surfactant micelles and aqueous solutions was characterized by a mole fraction micelle-phase/aqueous phase partion coefficient, $K_m$. Values of log $K_m$. for BTEX compounds in surfactant solutions of this study range from 2.95 to 3.76(100mM SDS) and 2.95 to 3.49(117mM $SOFTANOL\circledR-90$. Log $K_m$ appears to be a linear function of log $K_{ow}$ for SDS and $SOFTANOL\circledR-90$. A knowledge of partitioning of BTEX in aqueous surfactant system can be a prerequisite for the understanding of the behavior of hydrophobic organic compounds in soil-water systems in which surfactants play a role in remediation of contaminated soil and facilitated transport.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.20 no.5
• /
• pp.841-851
• /
• 1996

The purpose of this study is to investigate the backstaining generated during cellulase treatment for indigo-dyed denim. The results were as follows. 1. High generating conditions of the backstaining were as same as best conditions for cellulose activity (temperature at 6$0^{\circ}C$, pH at about 4.5~5.5, treatment time at 40 min. and enzyme concentration at 2g/l). And also, liquor ratio, sample weight and repeated-use cycle of liquor had influenced on the backstaining. 2. The backstaining was decreased about 30~40% when various additives, that is, surfactant, anti-backstaining agent (C.M.C) and softners were added. 3. A application of image processing on the backstaining evaluation was more effective than method by reflectance, particullarly in out of level fabrics. In image analysis, the backstainings were measured by histogram between 256 gray levels.

• Tuberculosis and Respiratory Diseases
• /
• v.71 no.3
• /
• pp.163-171
• /
• 2011

Recently published articles on interstitial lung disease (ILD) have focused on the accurate diagnosis of idiopathic pulmonary fibrosis (IPF), serum biomarkers, acute exacerbation of IPF, the prognostic factors of ILD and the trial of new treatment. In particular, reports on the serum biomarkers such as CC-chemokine ligand 18, surfactant protein, circulating fibrocytes, and acute exacerbation of IPF are sufficient to be mentioned here. Pirfenidone therapy is the most important trial for the treatment of IPF. Other newer treatment trials such as interferon-gamma, sildenafil and imatinib have been reported to be unsuccessful. On the other hand, the sirolimus trial for lymphangioleiomyomatosis is promising. Combined pulmonary fibrosis and emphysema and IgG4-related disease are established to be the new disease entities of ILD.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.159-159
• /
• 2007

In order to reduce a signal delay in ULSI, low resistive metal and intermetal dielectric material of low dielectric constant are required. Ordered mesoporous silica film is proper to intermetal dielectric due to its low dielectric constant and superior mechanical properties. In this study, ordered mesoporous silica films was synthesized using TEOS (tetraethoxysilane) / MTES (methyltriethoxysilane) mixed silica precursor and Brij-$76^{(R)}$ surfactant. These films had the porosity of 40% and dielectric constant of 2.5. To lower dielectric constant, the ordered mesoporous silica films were surface-modified by HMDS (hexamethyldisilazane) treatment. HMDS substituted -OH groups on the surface of silica wall for -Si$(CH_3)_3$ groups. After the HMDS treatment, ordered mesoporous silica films were calcined at various calcination temperatures. Through the investigation, it was concluded that the proper calcination temperature is necessary as aspects of structural, electrical, and mechanical properties.

• Journal of the Korean Society for Heat Treatment
• /
• v.18 no.4
• /
• pp.242-246
• /
• 2005

Silver nanoparticles were synthesized by liquid phase reduction method from aqueous silver nitrate solution and borohybride as a reduction agent. The morphology, particle size and shape were influenced by the reaction conditions such as the concentration of $AgNO_3$, a reduction agent and addition of surfactant. The particle size decreased with decreasing the concentration of silver nitrate and using a borohydride. The obtained Ag particles showed the spherical shape with the range of 10-20 nm.

• 한국생물공학회:학술대회논문집
• /
• 2000.04a
• /
• pp.442-445
• /
• 2000

Amphiphilic polyurethane(APU) particle is a polymeric surfactant, and could increase the solubility of 2-methylnaphthalene significantly. 2-Methylnaphthalene was recovered by the precipitation of APU particles and was degraded by Acinetobacter sp. K2-2. APU particle was recovered and reused after treatment of triethylamine.

• Journal of Chest Surgery
• /
• v.24 no.8
• /
• pp.797-801
• /
• 1991

Reexpansion pulmonary edema following pneumothorax, atelectasis, massive pleural effusion are clinically uncommon, but sometimes life threatening progression. Reexpansion pulmonary edema is usually ipsilateral but rarely contralateral or both. Reexpansion pulmonary edema was occurred when chronically collapsed lung is rapidly reexpanded by evacuation of large amounts of air or fluid. The pathogenesis of the reexpansion pulmonary edema is unknown but is probably mutifactorial. The etiological factors of the reexpansion pulmonary edema are chronicity of the lung collapse, technique of the reexpansion, airway obstruction, loss of the surfactant, and pulmonary artery pressure changes. In the treatment of the chronically collapsed lung, physician must be remembered the possible events, and to prevent of the complication.

• Clinical and Experimental Pediatrics
• /
• v.48 no.10
• /
• pp.1096-1101
• /
• 2005

Purpose : Recently, early surfactant replacement and tidal volume based gentle ventilation has been a fundamental treatment of respiratory distress syndrome(RDS). The aims of this study were to survey the changes in ventilator care duration and rate of complication in RDS groups. Methods : We performed a retrospective study of 255 newborn infants less than 1,500 g admitted to the neonatal intensive care unit(NICU) and discharged from January 1999 to December 2003. 141 of 255 newborn infants were RDS groups that required invasive management, such as endotracheal intubation, surfactant replacement and assisted ventilation. We analyzed epidemiologic data to study the changes in ventilator care duration and outcome of RDS groups. Results : Of 141 RDS groups, 135 were mild to moderate RDS groups and only 6 were severe RDS groups. 24(17.8%) of 135 mild to moderate RDS groups and 3(50%) of 6 severe RDS groups were antenatal no use of maternal dexamethasone. 127(90.1%) of 141 RDS groups underwent replacement of surfactant during 3 hours after birth. 121(85.9%) weaned within 48 hours. Conclusion : Our study shows a decreased frequency of severe RDS by a antenatal use of maternal dexamethasone and decreased duration of ventilator care by early surfactant replacement and gentle ventilation.