• Applied Chemistry for Engineering
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• v.5 no.5
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• pp.795-800
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• 1994

The detergencies of these new functional anionic surfactants, sodium monoglycerol ${\alpha}$-sulfonated alkanoates, were investigated and compared with those of two commercial surfactants, that is, sodium ${\alpha}$-sulfonated alkanoic acid methyl ester and sodium alkyl benzene sulfonate. According to the variation of the hydrophobic alkyl chain length, the order of detergency was shown to be $C_{16}$>$C_{18}$>$C_{14}$>$C_{12}$. From the comparision experiment for the detergency and the various fundamental properties of two other surfactants, it was found that sodium monoglycerol ${\alpha}$-sulfonated hexadecanonate has the most outstanding characteristics of detergency. Possibly this result shows light on its industrial application as a nonpolluting detergent.

• YAKHAK HOEJI
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• v.20 no.1
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• pp.19-26
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• 1976

Sixteen compounds of 2-aminobenzothiazole derivatives were synthesized from alkyl ($C_{1-5}$) p-aminosalicylate by thiocyanation reaction. The NMR spectra of synthesized compounds showed that they were actually mixture of 5-hydroxy-6-alk-oxycarbonyl-2-aminobenzothiazole [alkoxy=methoxy(Ia), ethoxy (IIa), n-propoxy (IIIa), iso-propoxy (IVa), n-butoxy (Va), iso-butoxy (VIa), n-amoxy (VIIa), iso-amoxy(VIIIa)] and 7-(1b), ethoxy(IIb), n-propoxy(IIIb), iso-propoxy(IVb), n-butoxy(Vb), iso-butpxy (VIb), n-amoxy (VIIb), iso-amoxy (VIIIb)]. The mixtures of two isomeric benzothiazole were separated by two isomers varied with the kind of alkyl chain in alkyl p-aminosalicylate. These compounds were subjected to the test for antimicrobial activities using Staphylococcus aureus and Escherichia coli by tube dilutioin method. The seven compounds, Ia, IIa, IIIa, VIa, IIIb, IVb and Vb showed inhibition of the growth of S. aureus at the concentration of 10${\mu}$g/ml. As to the growth of E. coli, IVb, VIb, VIIb, and VIIIb were observed inhibition at the concentration of 1${\mu}$g/ml. Ia, IIa, IIIa, VIIa, Va, VIIIa, and IIb exhibited potential antimicrobial activities against showed inhibition of the growth of E.coli at the concentration of 100${\mu}$/ml.

• Korean Journal of Weed Science
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• v.30 no.3
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• pp.233-242
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• 2010

This study was conducted to know that if ionic liquids can be applicable as control agents of harmful algae in water-ecosystem and to find out problems caused by ionic liquid application. Firstly, the differential selectivity of various fresh-water algal species to several 1-alkyl-3-methylimidazolium chloride ionic liquids was investigated. There was a distinct differential response between alkyl chain lengths from butyl to dodecyl and towards the algal organisms : Generally algicidal activity was increased with increase of chain length and among the algae used in this study, Stephanodiscus hantzschii f. tenuis, Oscillatoria tenuis and Spirulina pratensis were most sensitive to 1-dodecyl-3-methylimidazolium chloride (MAIC12), next was Microcystis aeruginosa, and the others were relatively less sensitive to the chemical. The selectivity degree was about ten to twenty times based on the $EC_{80}$ (Effective concentration required for 80% growth inhibition). Secondly, an activity persistence of ionic liquids was investigated in natural mimic condition (using water bottle containing soil-sediments under the greenhouse condition). At the application of $1.0{\mu}g\;mL^{-1}$ of 1-octyl-3-methylimidazolium chloride (MAIC8), the algal growth did not occur at all until 6 days after treatment(DAT) and observed a only little growth at 9 DAT. But the algae grew rapidly after 9 DAT. So at 20 DAT, total chlorophylls was $264.4{\mu}g\;L^{-1}$ and the growth was inhibited by 58.2% compared to untreatment. On the other hand, MAIC12 also had a similar persistence pattern to MAIC8, showing nearly 5 times more activity than MAIC8. At 20 days after $0.2{\mu}g\;mL^{-1}$ application of MAIC12, that is, total chlorophylls was $251.2{\mu}g\;L^{-1}$ and the growth was inhibited by 55.2% compared to untreatment. In summary, 1-alkyl-3-methylimidazolium chloride ionic liquids is likely to be applicable for selective control of harmful algae as potent compounds having long lasting activity. However, the difficulty of degradation seems to be a limiting factor in an eco-friendly application of the compounds.

• Journal of the Korean Applied Science and Technology
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• v.10 no.1
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• pp.83-91
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• 1993

The syntheses of urocanic acid esters was optimized, starting from p-toluenesulfonic acid salt of this acid and long chain fatty alcohols in the organic solvent and extracting water from it by means of azeotropic Compound. The salts of these urocanic acid esters showed amphoteric properties, but their micellization enhances their rate of hydrolysis leading to the free amine. Nevertheless the long chain gives to the esters themselves an amphoteric character allowing their solubilization in micellar media and in microemulsions the result, yield could enhanced.

• Journal of Satellite, Information and Communications
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• v.10 no.1
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• pp.67-70
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• 2015

We studied the state of the dual liquid crystal (LC) alignment which displays both homeotropic and homogeneous alignment on blended polyimide (PI) layer. The research was conducted using rubbing method at different imidizing temperatures and the blended PI was made using homeotropic PI having an alkyl side chain and homogeneous PI without the side chain. The uniform LC alignments were achieved, and have thermal stability. The results of contact angles were similar to that of pretilt angles.

• Analytical Science and Technology
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• v.10 no.2
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• pp.139-145
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• 1997

Alkylbenzenes used as synthetic lubricant base oils have been analyzed to find the quantity of mono- and di-substituted alkyl aromatic hydrocarbon compositions and the number of carbon atoms in alkyl chains by $^{13}C$-NMR, near-infrared, and UV-Vis spectroscopy. Also, linear long chain alkylated benzene in the engine lubricants was analyzed quantitatively by infrared spectroscopy.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.345-345
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• 2006

It is well known that poly(glutamate)s with long n-alkyl side chains form thermotropic liquid crystalline state by melting of the side-chain crystallites and also poly(glutamate)s such as poly(${\gamma}-benzyl\;L-glutamate$ )(PBLG), poly(${\gamma}-n-alkyl\;L-glutamate$), etc. in solvent form the isotropic, biphasic and liquid crystalline phases which contains cholesteric and columnar liquid crystalline forms depending on the polypeptide concentration. Although there is no diffusion study for PBLG in liquid crystalline state, because it is difficult to observed $^{1}H$ spectrum of PBLG in liquid crystalline state for its very short $^{1}H\;T_{2}$. In this study, the diffusional behavior of rodlike PBLG in concentrated solution is successfully elucidated as studied by the field-gradient $^{1}H$ NMR methods.

• Journal of the Korean Applied Science and Technology
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• v.16 no.3
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• pp.231-235
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• 1999

Several instances of synergistic interaction have been identified between alkyl amine oxide and long chain fatty acohol polyethoxylates in various surfactant formulation. The purpose of this study was examined whether these benefits could be observed within the framework of generic hand-surface cleaning formulations. Comparative evaluation were also carried out to determine the performance characteristics of low-and zero-phosphate systems in which amine oxide and alcohol ethoxylates are used. Best cleaning was observed with 1:1 mixtures of the subject surfactants, but substantial improvements over fatty alcohol ethoxylate alone also were noted with formulations that contained lower ratios of amine oxide.

• Journal of the Korean Applied Science and Technology
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• v.6 no.1
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• pp.67-73
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• 1989

The adsorptions of 2-(dimethylalkylammonio)propanoates with straight chain alkyl group having from 12 to 16 carbon atoms on the liquid-air interface were decreased while lowering the surface tensions at critical micelle concentrations. In micellization, the standard free energy changes per methylene in alkyl group were found to make same contribution to the micelle formation of corresponding C-alkylcarboxybetaines, and the standard enthalpy and entropy changes were studied within the range of temperature from 30 to $50^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• v.27 no.11
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• pp.1737-1740
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• 2006

The optimized structures and complexation energies of bis(18-crown-6-ether) analogue (2) of Trgers base (1) with a series of primary alkylbisammonium ions have been calculated by DFT B3LYP/6-31G(d,p) method. The calculated complexation efficiency (-142.84 kcal/mol) of 2 for butane-1,4-diylbisammonium guest is better than twice of the value (-61.40 kcal/mol) for butylammonium ion. The multiple hydrogen-bond abilities for the complexes are described as the function of the length of the alkyl substituents of the bisammonium guests with normal-alkyl chain [$-(CH_2)_{n-}$, n = 4-8]. The longer bisammonium guest shows the stronger hydrogen-bonding characterizations (the distance and the quasi-linear angle of the N-H…O) to the host 2 than the shorter bisammonium ions. These calculated results agree with the experimental data of the complexation of 2 with bisammonium salts ([$NH_3(CH_2)_nNH_3$] $Cl_2$).