• Applied Chemistry for Engineering
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• v.23 no.5
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• pp.433-439
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• 2012

In this study, a cationic surfactant BHMAS (N,N-bis-(3'-n-dodecyloxy-2'-hydroxypropyl)-N-methyl-2-hydroxyethylammonium methyl sulfate) having two lauryl and three hydroxyl groups was synthesized by the reaction of n-dodecyl glycidyl ether and 2-aminoethanol followed by the quarternization with dimethyl sulfate. The structure of the product was elucidated by $^{1}H-NMR$ and FT-IR. The CMC (critical micelle concentration) and surface tension of BHMAS at CMC condition were found to be $9.12\;{\times}\;10^{-4}$ mol/L and 28.71 mN/m respectively. Dynamic surface tension measurements using a maximum bubble pressure tensiometer indicated that a relatively long time was required to saturate the interface between air and aqueous surfactant solution. The interfacial tension measured between 1 wt% surfactant solution and n-decane reached an equilibrium value of 0.045 mN/m in 5 min. The adsorption capacity of the synthesized surfactant was observed to be excellent, which suggests that the surfactant can be used as a softening agent during a laundry process.

• Elastomers and Composites
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• v.37 no.2
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• pp.99-106
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• 2002

In this work, the surface properties and mechanical interfacial properties of the carbon blacks treated by oxygen plasma were investigated. The surface properties of carbon black by oxidation process of oxygen plasma were studied in acid-base surface value, zeta potential, and X-ray photoelectron spectroscopy (XPS). And their mechanical interfacial properties of the carbon black/rubber composites were evaluated by the composite tearing energy ($G_{III}c$). As a result, it was found that the introduction rate of oxygen-containing polar functional groups, such as carboxyl, hydroxyl, lactone, and carbonyl groups, onto the carbon black surfaces was increased by increasing the plasma treatment time. It revealed that the polar rubber, such as acrylonitrile butadiene rubber (NBR), showed relatively a high degree of interaction with oxygen-containing functional groups of the carbon black surfaces, resulting in improving the tearing energy ($G_{III}c$) of the carbon black/acrlyonitrile butadiene rubber composites.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.262-262
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• 2012

Modifications of graphenes have been studied for catalytic applications due to their advantages such as high surface area, conductivity and thermal stability. In this research, individual graphene oxide (GO) sheets were exfoliated from graphite using Hummers and Offeman method. Pd nano-particles were deposited on the GO surface using Pd2+ ion exchange where hydroxyl groups on the GO act as nucleation sites of Pd nanoparticles and their dispersions. The thermal treatments of the Pd-GO in H2 flow produced Pd-Graphene nanocomposites. Their catalytic performances in Sonogashira reaction were investigated. Morphological and chemical structures of the GO, Pd-GO, and Pd-Graphene were investigated using FT-IR, XRD, TEM, STEM, and XPS. The catalytic performances have been investigated using microwave reactor.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.276-280
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• 1999

Electrical properties of electrochromic (EC) InN thin films prepared by rf ion plating were studied. There was a correlation between the electrical properties and the electrochromism in the InN films, particularly, carrier concentration changes were responsible for the electrical resistivity changes of the films due to the electrochromism. These carrier concentration changes were caused by chemisorbed hydroxyl groups and protons. From these results, it was proved that the carrier concentration changes of the InN films was responsible for the electrochromism in the visible and near-infrared region.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.195-195
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• 2012

Recently, graphene based solution-gated field-effect transistors (SGFETs) have been received a great attention in biochemical sensing applications. Graphene and reduced graphene oxide (RGO) possess various advantages such as high sensitivity, low detection limit, label-free electrical detection, and ease of fabrication due to their 2D nature and large sensing area compared to 1D nanomaterials- based nanobiosensors. Therefore, graphene or RGO -based SGFET is a good potential candidate for sensitive detection of protons (H+ ions) which can be applied as the transducer in various enzymatic or cell-based biosensing applications. However, reports on detection of H+ ions using graphene or RGO based SGFETs have been still limited. According to recent reports, clean graphene grown by CVD or exfoliation is electrochemically insensitive to changes of H+ concentration in solution because its surface does not have terminal functional groups that can sense the chemical potential change induced by varying surface charges of H+ on CVD graphene surface. In this work, we used RGO -SGFETs having oxygen-containing functional groups such as hydroxyl (OH) groups that effectively interact with H+ ions for expectation of increasing pH sensitivity. Additionally, we also investigate RGO based SGFETs for bio-sensing applications. Hydroloytic enzymes were introduced for sensing of biomolecular interaction on the surface of RGO -SGFET in which enzyme and substrate are acetylcholinesterase (AchE) and acetylcholine (Ach), respectively. The increase in H+ generated through enzymatic reaction of hydrolysis of Ach by AchE immobilized on RGO channel in SGFET could be monitored by the change in the drain-source current (Ids).

• Journal of Fashion Business
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• v.7 no.2
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• pp.69-81
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• 2003

Among the various properties of textile fabrics, the moisture-related properties are important for the textile processes or the apparel comfort characteristics. Alkaline hydrolysis results in pitting on the surface of fibers and increases the amount of hydroxyl and carboxyl end groups of the PET molecules on the fiber surface. The purpose of this study is to investigate the moisture-related properties of PET fabrics treated with quaternary ammonium compound/alkaline solution. The wetting and wicking properties of the PET fabrics were measured using the following experiments: contact angle, surface free energy, work of adhesion, vertical wicking height, moisture regain, and frictional static voltage. It was concluded that by the alkaline hydrolysis process, surface hydrophilicity and reactivity were considerably improved especially at lower levels of weight loss% and that the pitting of the fiber surface resulted in at higher levels of weight loss% was disadvantageous in moisture-related properties of PET.

• Environmental Engineering Research
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• v.20 no.1
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• pp.41-50
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• 2015

The cyanobacterium Anabaena doliolum Ind1 isolated from a coal mining site was tested for removal of cadmium at optimum pH 7.0 and temperature $25^{\circ}C$. The organism recorded high percentage of metal removal (92-69%) within seven days of exposure to 0.5-2.0 ppm cadmium. Biosorption onto the cell surface was the primary mode of metal removal. Fourier transform infrared spectroscopy (FTIR) established hydroxyl, amides, carboxyl, sulphate and carbonyl groups to be the major functional groups on the cell surface involved in cadmium binding. Cellular ultrastructure and a range of vital physiological processes (i.e., photosynthetic pigments, respiration, photosynthesis, heterocyst frequency and nitrogenase activity) remained unaffected upon 0.5 ppm treatment; higher concentrations of cadmium exerted visible adverse effects. Amongst the five photosynthetic pigments tested, phycocyanin was the most targeted pigment (inhibition was 15-89%). Both respiration and photosynthetic activities were inhibited by cadmium with more severe effect seen on respiration. 2.0 ppm cadmium exposure also had drastic negative effect on nitrogenase activity (87% decreased).

• Textile Coloration and Finishing
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• v.6 no.3
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• pp.15-26
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• 1994

Cotton fabrics were treated with the cellulase which is an enzyme to decompose cellulose and its actional mechanism is known. The optimum condition of the cellulase to the cotton fabrics and the weight losses, tensile strengths of the treated cotton fabrics were also obtained. The cellulase performs a specific catalytic action on the ${\beta}-1$, 4-glucosidic bonds of the cellulose molecules and hydrolyzes them. For that reason, the negative surface charges of the cotton fabrics were increased by additional generation. of hyrdoxyl groups. The increased surface charges cause the decrease of dye adsorption by inhibiting the approach of the anions of direct dyes. But, it was overcome by the use of enough amount of salt, it means that sodium ions of the salt neutralize the almost all of negative charges of the cotton fabrics. The improvement of the water absorbency is also due to the increased hydroxyl groups In addition, their handles including the mechanical properties were measured and caculated by KES system which is a measuring apparatus that numerizes and objectificates human's feeling, especially touch. As the results, we knew that KOSH(stiffness) and FUKURAMI(fulness & softness) were decreased and that NUMERI(smoothness) was increased.

• Applied Chemistry for Engineering
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• v.27 no.1
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• pp.86-91
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• 2016

Three amorphous silicas and SBA-15 were employed as supports, which were capable of confining ionic liquid (IL) and metallocene in the nanopore. Ionic liquid functionalized silica was prepared by the interaction between the chloride anions of 1,3-bis(cyanomethyl)imidazolium chloride and the surface OH groups. Metallocene and methylaluminoxane (MAO) were subsequently immobilized on the ionic liquid functionalized silica for ethylene polymerization. The metallocene supported on ionic liquid functionalized XPO-2412 and XPO-2410 having a larger pore diameter compared to SBA-15 showed higher activity than that of using supported catalyst without ionic liquid functionalization. However, the activity of metallocene supported on SBA-15 decreased after ionic liquid functionalization, suggesting that the diffusion of ethylene monomer and cocatalyst to the active site of nanopore was restricted during ethylene polymerization. This could be resulted from significant reduction of the pore diameter due to the immobilization of ionic liquid and $(n-BuCp)_2ZrCl_2$ and MAO. The effect on polymerization activity in accordance with the concentration of hydroxyl groups on the surface was also investigated. The polymerization activity increased as the concentration of hydroxyl groups on amorphous silica increased. The polymerization activities of metallocene supported on silica showed the similar trend after ionic liquid functionalization.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3269-3273
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• 2013

Graphene oxide (GO) has been of particular interest because it provides unique properties due to its high surface area, chemical functionality and ease of mass production. GO is produced by chemical exfoliation of graphite and is decorated with oxygen-containing groups such as phenol hydroxyl, epoxide groups and ionizable carboxylic acid groups. Due to the presence of those functional groups, GO can be utilized as a novel platform for hybrid nanocomposites in chemical synthetic approaches. In this work, GO-$SnO_2$ nanocomposites have been prepared through the spontaneous formation of molecular hybrids. When $SnO_2$ precursor solution and GO suspension were simply mixed, $Sn^{2+}$ was spontaneously formed into $SnO_2$ nanoparticles upon the deoxygenation of GO. Through further chemical reduction by adding hydrazine, reduced GO-$SnO_2$ hybrid was finally created. Our investigation for the electrocapacitive properties of hybrid electrode showed the enhanced performance (389 F/g), compared with rGO-only electrode (241 F/g). Our approach offers a scalable, robust synthetic route to prepare graphene-based nanocomposites for supercapacitor electrode via spontaneous hybridization.