• Korean Journal of Food Science and Technology
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• v.50 no.4
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• pp.357-361
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• 2018

This study aimed to explore efficient DNA extraction methods using tree nuts. Four different DNA extraction procedures, including silica membrane method, modified silica method, cetyltrimethylammonium bromide (CTAB) method, and modified CTAB method were examined for their relative efficiency in extracting DNA from pistachio, pine nut, almond, hazelnut, cashew nut, walnut, and peanut. The quality and quantity of the extracted DNA were subsequently assessed by spectrometric measurements, gel electrophoresis, and PCR amplifications. CTAB method was the most appropriate one for extracting DNA from pine nut, cashew nut, pistachio, and peanut. However, it could be replaced by the silica membrane method for walnut and modified CTAB method for almond and hazelnut.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.6
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• pp.673-679
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• 2008

In this study, Mesoporous silica were prepared from hydrothermal synthesis using gel mixture of tetraethylorthosilcate (TEOS) as silica source and cetyltrimethylammonium bromide(CTMABr) as a template. In the optimum synthesis cause, molar ratio of template and silica changed. The surface and structure properties of Mesoporous silica were determined by XRD, SEM, and BET. N$_2$ adsorption isotherm characteristics, including the specific surface area(S$_{BET}$), total pore volume(V$_T$), and average pore diameter(D$_{BJH}$), were determined by BET. Also, the adsorption character of Pb(II) and Cd(II) ion on Mesoporous silica were measured using ICP. As a result, a SBET of 100$\sim$1,500 m$^2$/g was determined from the N$_2$ adsorption isotherm. Also, the average pore diameter of 2$\sim$4 nm. The adsorption of Pb ion and Cd ion on Mesoporous silica become different depending on the pH of solution. The adsorption amount of Mesoporus silica had higher than that of silicagel.

• Journal of the Korean Chemical Society
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• v.35 no.1
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• pp.70-77
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• 1991

1-Benzyl-4-iodomethyl-2-azetidinone(BIMA) was synthesized and its electrochemical reduction was investigated by direct current, differential pulse polarography, cyclic voltammetry and controlled potential coulometry. The irreversible two electron transfer on reductive dehalogenation of iodo group proceeded to form 1-benzyl-4-methyl-2-azetidinone by EEC electrode reaction mechanism at the first reduction step(-1.35 volts vs. Ag-AgCl). The polarographic reduction waves separated into two reduction steps due to anionic surfactant (sodium lauryl sulfate) effects, while the waves were shifted to the positive potential as the concentration of cationic surfactant (cetyltrimethylammonium bromide) increased. Upon the basis of results on the product analysis and interpretation of polarogram with pH variable, EEC electrochemical reaction mechanism was suggested.

• Applied Chemistry for Engineering
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• v.30 no.1
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• pp.17-22
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• 2019

In this study, cationic gemini surfactants were synthesized by increasing the length of the hydrophobic chain and using 1,4-butanediol as a spacer, and the result was confirmed by $^1H-NMR$. The synthesized surfactant was a white powder, and Kraffts point was below $0^{\circ}C$. Surface tension measurements revealed that the evaluated critical micelle concentration (c.m.c) was $1.8{\times}10^{-3}{\sim}6.5{\times}10^{-4}mol/L$ with a surface tension of 22.5~26.1 dyne/cm at the c.m.c. The initial foam height for CG 14-6E-14 estimated by Ross-Miles method was 16 cm and after 5 minutes the height was 14 cm. It was confirmed that the initial foam force and foam stability were the highest. The foam test and emulsion stability of synthesized gemini cationic surfactants were also compared to those of cetyltrimethylammonium bromide (CTAB), a commoly used surfactant.

• Korean Journal of Chemical Engineering
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• v.35 no.11
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• pp.2269-2282
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• 2018

Mixed micelle formation behavior of cationic surfactant-cetyltrimethylammonium bromide (CTAB) and anionic surfactant sodium dodecyl sulfate (SDS) in aqueous as well as in urea medium from 303.15 K to 323.15 K at 5 K interval was carried out by conductometric method. The differences between the experimental values of critical micelle concentrations (cmc) and ideal critical micelle concentrations ($cmc^{id}$) illustrate the interaction between the amphiphiles studied. The values of micellar mole fraction ($X_1^{Rub}$ (Rubingh), $X_1^M$ (Motomura), $X_1^{Rod}$ (Rodenas) and $X_1^{id}$(ideal) of surfactant CTAB determined by different proposed models and outcome indicate high involvement of CTAB in SDS-CTAB mixed micellization, which enhance by means of the augment of mole fraction of CTAB. The negative value of interaction parameter (${\beta}$) showed an attractive interaction involving CTAB and SDS. Activity coefficients were less than unity in all case, which also reveals the presence of interaction between CTAB & SDS. The negative ${\Delta}G^0_m$ values imply the spontaneous mixed micellization phenomenon. The attained values of ${\Delta}H^0_m$ were positive at inferior temperature, while negative at superior temperature. The negative ${\Delta}H^0_m$ values in urea ($NH_2CONH_2$) medium illustrate exothermic micellization process. The magnitudes of ${\Delta}S^0_m$ were positive in almost all cases. The excess free energy of mixed micelle formation (${\Delta}G_{ex}$) was found to be negative, which indicates the stability of mixed micelle as compared to the individual's components micelles.

• Korean Journal of Chemical Engineering
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• v.35 no.11
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• pp.2313-2320
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• 2018

Tetramethylene-1,4-bis(N,N-dodecylammonium bromide), cationic gemini surfactant, (12-4-12) was first synthesized with an one-step and shortened procedure and its interfacial and antimicrobial properties were compared with a conventional single-chain cationic surfactant, cetyltrimethylammonium bromide (CTAB). The interfacial and thermodynamic properties of both surfactants reveal that critical micelle concentration (CMC) of this novel synthetic cationic dimeric surfactant is lower than that of cationic monomeric surfactant at almost 15 times of its magnitude, which is due to the increase in hydrophobicity of the surfactant molecules by having dual hydrocarbon chains. In comparison with CTAB, the produced compound 12-4-12 yields much better interfacial and thermodynamic properties. The antimicrobial activities of the synthesized gemini surfactant were tested against eight strains of bacteria, as well as two strains of fungi. The results showed that both 12-4-12 compound and CTAB exhibited higher inhibitory effects on the growth of Gram-positive bacteria and fungi than that of Gram-negative bacteria. The minimum inhibitory concentrations in molar of 12-4-12 against all tested Gram-negative bacteria were lower than those of CTAB, which is hypothetically due to the lower HLB together with smaller CMC values of our gemini surfactant.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1336-1338
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• 2010

Three cobalt-iron Prussian Blue Analogues (PBAs) nanotubes contained with different alkali metal cations of K, Rb or Cs, respectively, were prepared by using cetyltrimethylammonium bromide (CTAB)/ethanol-water micelles as soft templates. The products were characterized by energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron micrograph (SEM), which confirmed the composition of the substances and their unique nanotube structures. Furthermore, the formation mechanism of the PBAs nanotubes was discussed and provided useful insight for further synthesis of nanotubes of other Prussian blue analogues.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1527-1535
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• 2012

Selection of the most informative molecular descriptors from the original data set is a key step for development of quantitative structure activity/property relationship models. Recently, mutual information (MI) has gained increasing attention in feature selection problems. This paper presents an effective mutual information-based feature selection approach, named mutual information maximization by replacing collinear variables (MIMRCV), for nonlinear quantitative structure-property relationship models. The proposed variable selection method was applied to three different QSPR datasets, soil degradation half-life of 47 organophosphorus pesticides, GC-MS retention times of 85 volatile organic compounds, and water-to-micellar cetyltrimethylammonium bromide partition coefficients of 62 organic compounds.The obtained results revealed that using MIMRCV as feature selection method improves the predictive quality of the developed models compared to conventional MI based variable selection algorithms.

• Bulletin of the Korean Chemical Society
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• v.26 no.11
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• pp.1677-1681
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• 2005

Aldol condensation of 2-acetylthiophene, 2-acetylpyrrole and 2-acetylpyridine with different aromatic aldehydes were carried out in water in heterogeneous phases in the presence of cetyltrimethylammonium bromide as cationic surfactant at room temperature. All the reactions occur in a short time with excellent yields of steroselective hetarylpropanones in water as environmental friendly solvent.

• Journal of environmental and Sanitary engineering
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• v.10 no.3
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• pp.78-84
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• 1995

Cationic surfactants can be used to modify surface of solids to promote adsorption of hydrophobic organic compounds. This behavior is due to the surfactant forming aggregate structure on the solid surface. Partition coefficients are commonly used to quantify the distribution of organic pollutants between the aqueous and particulate phases of aquatic system Partitioning of hydrophobic compounds to cetyltrimethylammonium bromide ( CTAB ) coated silicate has been investigated as a function of surfactant surface coverage at I=0 and 0.1 ionic strength. Toluene, Xylene, TCI sorption experiments demonstrated that the CTAB coated silicate was able to remove these hydrophobic organic compounds from solution The hydrophobic organic compound with the higher Kow had higher removals than lowest Kow hydrophobic organic compound.