• Journal of the Korean Applied Science and Technology
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• v.9 no.2
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• pp.107-117
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• 1992

The synthesis and solution properties of polyglycerol alkyl ether($R_{12}Gn$) are described. The phase behavior, surface tension, cloud point and HLB value of polyglycerol dodecyl ether in aqueous solution and in mixed solution of surfactant /water /oil have been investigated and compared with values of polyoxyethylene dodecyl ether. The surface tension showed that $R_{12}Gn$ have sufficiently low values of surface tension and cmc to serve as useful polyoxyethylene alkyl ether. The mesophases appearing in the $R_{12}Gn$ systems were more stable in a high temperature range than the mesophases of polyoxyethylene alkyl ether systems. The cloud point and HLB data indicated that addition of one glycerol group was equivalent to the addition of three oxyethylene group units, as far as the hydrophilic property was concerned. The phase diagrams of the polyglycerol alkyl ether /dodecane /water systems showed that the solubilizing and emulsifying powers of $R_{12}Gn$ were greater than those of polyoxyethylene alkyl ether. It is concluded that the polyglycerol chain can be even more useful as hydrophilic group of nonionic surfactants than the polyoxyethylene chain.

• Bulletin of the Korean Chemical Society
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• v.25 no.10
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• pp.1531-1537
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• 2004

Twenty four thiol-functionalized ionic liquids based on imidazolium cation, 1-(12-mercaptododecyl)-3-alkylimidazolium salts, have been synthesized, and utilized to investigate the effects of alkyl-chain length and anion on the wettability of Au surfaces on the basis of self-assembled monolayers presenting [(CnSAMIM)X], where n = 1-6, X = Br, $BF_4$, $PF_4$ and $NTf_2$. Water wettabilities of the surfaces were measured as a water contact angle by contact angle goniometry. It was found that water wettability of the Au surfaces coated with imidazolium ions was largely dependent not only on counter anions but also on the length of alkyl chains. In the case of SAMs of N-alkylimidazolium ions having short length of N-alkyl chain (C1-$C_4$), anions played great role in determining water wettability of the surfaces.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.1
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• pp.36-41
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• 1998

Intercalation compounds of alkyl sulfonates into layered double hydroxides (LDH) have been directly synthesized. From the X-ray diffraction data and the alkyl sulfonates size, the orientation of the intercalated alkyl sulfonate into the layered double hydroxide was determined. The intercalated alkyl sulfonate is arranged with molecular chain perpendicular to the hydroxide layer with an antiparallel pattern.

• Macromolecular Research
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• v.16 no.4
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• pp.360-366
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• 2008

Poly(dialkoxyphenylene 1,3,4-oxadiazole)s were conveniently synthesized to compare their material properties of solvent solubility, thermal stability and molecular alignment with respect to alkyl chain length and meta/para-phenylene structure. All prepared polymers exhibited good solubility in co-solvents containing various volume levels of chloroform to trifluoroacetic acid. Meta-polymers showed slightly better solubility than para-polymers. All polymers produced were thermally stable up to $320^{\circ}C$. Photoluminescence of polymer films was observed with blue light emission at around 450 nm. X-ray diffraction patterns of all polymers indicated that they were composed of stacked molecular sheets with the same layer-to-layer distance of $3.4\;{\AA}$. However, side chain-to-side chain and main chain-to-main distances within the layers increased with increasing alkyl chain lengths. The meta-polymer chains were separated more than the para-polymer chains.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.248.2-248.2
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• 2003

The 18 ureidoceramide derivatives had been investigated for their cytotoxic activity against HT-29 colon cancer, Caki-2 renal cancer, A549 lung cancer, PC-3 prostate cancer, HL -60 leukemia cell using MTT assay. Cytotoxic activity was strongly influenced by the substituted alkyl chain length and the optimal alkyl chain length for cytotoxicity was C9-C12. (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.185.1-185.1
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• 2003

The 20 alkylsulfonylamido propanol derivatives had been investigated for their cytotoxic activity against HT-29 colon cancer, Caki-2 renal cancer, A549 lung cancer, PC-3 prostate cancer, HL-60 leukemia cell using MTT assay. Cytotoxic activity was strongly influenced by the substituted alkyl chain length and the optimal alkyl chain length for cytotoxicity was C11. Some of alkylsulfonylamido porpanol derivatives showed stronger activity than reference compound, B13.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.358.1-358.1
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• 2002

The 20 thiourea derivatives had been investigated for their cytotoxic activity using MTT assay. Cytotoxic activity was strongly influenced by the substituted alkyl chain length. but not by configuration of Cl and C2. The optimal alkyl chain length for cytotoxicity was C12. The 9 thiourea derivatives showed stronger activity than reference compound. B13. some of them gave 2-3 times stronger activity than B13. (omitted)

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1443-1454
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• 2011

Methods to prepare novel second-order nonlinear optical (2O-NLO) materials composed of all-silica zeolite (silicalite-1) and a series of 2O-NLO molecules having high second order hyperpolarizability constants (${\beta}$ values) are reviewed. These methods include the development of novel methods to incorporate a series of hemicyanine (HC) molecules into the channels of silicaite-1 films in uniform orientations. The first method is to incorporate HC molecules tethered with long alkyl chains (octadecyl or longer) into the silicalite-1 channels with the long alkyl chain side first through the hydrophobic-hydrophobic interaction between the long alky chains and the silicalite-1 channels. The second method is to incorporate the HC molecule tethered with a medium length alkyl chain (nonyl) into the silicalite-1 channels with the medium length alkyl chain side first through hydrophobic-hydrophobic interaction between the medium length alky chain in the photoexcited state and the silicalite-1 channels. The third method is to incorporate the HC molecule tethered with propionic acid into the silicalite-1 channels with the propionic acid side last mediated by a tetrabultylammonium cation ion-paired to the propionate unit. A method to prepare a novel third-order nonlinear optical (3O-NLO) material composed of zeolite-Y and PbS or PbSe quantum dots is also reviewed. This Account thus describes a promising new direction to which the search for highly sensitive 2O-NLO and 3O-NLO materials has to be conducted and a new direction to which zeolite research and applications have to be expanded.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.5
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• pp.362-368
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• 2021

A homeotropic liquid crystal (LC) alignment state on rubbed fluorinated self-assembled monolayers (FSAMs) is described according to alkyl chain length. A simple procedure, gas-phase method, for the preparation of FSAM was used. The average optical transmittance in the visible light range of FSAMs were 76.63% to 78.21%, which were superior to the conventional polyimide layer having a transmittance of 75.89%. In addition, the excellent homeotropic LC alignment characteristics of FSAMs were observed through pretilt angle measurement and polarized optical microscope images. By measuring the contact angles and the surface energies of FSAMs, it was confirmed that pretilt angles of LC molecules increased according to the alkyl chain length. High optical transparency and uniform homeotropic LC alignment characteristics of FSAMs showed the possibility of FSAMs as an LC alignment layers.

• Bulletin of the Korean Chemical Society
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• v.13 no.3
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• pp.259-265
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• 1992

Cyclic voltammetric behavior of symmetric (dimethyl, diheptyl, dioctyl, dibenzyl) and asymmetric (methyloctyl, methyldodecyl, methylbenzyl) viologens was investigated in homogeneous aqueous solution and sodium dodecyl sulfate (SDS) micellar media. In SDS-free 0.1 M NaCl solutions, the reduction potential is less negative as the chain length of alkyl substituent is longer. This is due to the stabilization of the reduced cationic radical and neutral form of viologen by adsorption on electrode surface. The adsorbed species show the "aging-effect". With the exceptions of methyldodecyl viologen and methylbenzyl viologen, the viologens show strong tendency of conproportionation reaction between viologen dications and neutral forms. In cases of methyldodecyl viologen and methylbenzyl viologen, the conproportionation reaction is kinetically disfavored, though it is thermodynamically favorable. SDS micelles dissolve the adsorbed species and the viologens exhibit two reversible redox processes in SDS micellar solutions. The reduction potentials of viologens in SDS micellar solutions depend little on the length of alkyl chain. Benzyl-substituted viologens are more easily reduced than the alkyl substituted viologens, presumably due to electron-withdrawing character of benzyl group.