• Carbon letters
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• v.13 no.4
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• pp.212-220
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• 2012

Orange peel (OP) exhibits a sorption capacity towards anionic dyes such as reactive blue 19 (RB19). Cetyltrimethylammonium bromide (CTAB) as a cationic surfactant was used to modify the surface nature of OP to enhance its adsorption capacity for anionic dyes from an aqueous solution. Four adsorbents were investigated: the OP, sodium hydroxide-treated OP (SOP), CTAB-modified OP and CTAB-modified SOP. The physical and chemical properties of these sorbents were determined using nitrogen adsorption at 77 K and by scanning electron microscope and Fourier transform infrared spectroscopy techniques. The adsorption of the RB19 dye was assessed with these sorbents at different solution pH levels and temperatures. The effect of the contact time was considered to determine the order and rate constants of the adsorption process. The adsorption data were analyzed considering the Freundlich, Langmuir, Elovich and Tempkin models. The adsorption of RB19 by the assessed sorbents is of the chemisorption type following pseudo-first-order kinetics. CTAB modification brought about a significant increase in RB19 adsorption, which was ascribed to the grafting of the sorbent with a cationic surfactant.

• Bulletin of the Korean Chemical Society
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• v.25 no.4
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• pp.560-562
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• 2004

• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1729-1734
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• 2007

The electrochemical behaviors of estrone in the presence of various surfactants were examined with great details. It is found that a cationic surfactant, cetyltrimethylammonium bromide (CTAB), obviously facilitates the electro-oxidation of estrone at carbon paste electrode (CPE) from the significant peak current enhancement and the negative shift of peak potential. Additionally, chronocoulometry and electrochemical impedance spectroscopy (EIS) were also used for further investigation of the electrode process of estrone, indicating that low concentration of CTAB exhibits excellent enhancement effects on the electrochemical oxidation of estrone, greatly enhances the diffusion coefficient and the electron transfer rate. Based on this, an electrochemical method was proposed for the determination of estrone. The oxidation peak current is proportional to the concentration of estrone in the ranges over 9.0 × 10?8 - 8.0 × 10?6 mol/L, and a low detection limit of 4.0 × 10?8 mol/L was obtained for 180s accumulation at open circuit (S/N = 3). Finally, this proposed method was demonstrated using estrone tablets with good satisfaction.

• 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.

• 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.

• Analytical Science and Technology
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• v.14 no.2
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• pp.167-172
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• 2001

The technique that could collect efficiently the hanji fibrous sludge from wastewater using surfactants was developed. When fibrous sludge of which concentration was about 80mg/L, was floated and collected, the optimum concentration of sodium oleate, the pore size of glass filter and the air flow rate were 10mg/L, $5-10{\mu}m$ and 200mL/min., respectively. The behavior of sodium oleate might be interfered by polyvalent cations such as $Ca^{2+}$. But when the concentration of $Ca^{2+}$ was less than 100mg/L, the interference effect did not appear. And when a typical cationic surfactant, cetyltrimethylammonium bromide(CTAB), was used, the collecting yield was less than that of sodium oleate, and the amount of foam was higher than sodium oleate. When 1mg/L of CTAB was added to the hanji sludge sample contained 1mg/L of $PAMID^{(R)}$, a dispersant, fibrous sludge was effectively coagulated, the flotation time was very short and the collecting yield was above 95%. But in the case, sodium oleate was inefficient.

• Korean Chemical Engineering Research
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• v.62 no.1
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• pp.99-104
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• 2024

In this study, a carbon coated hollow silicon (HSi/C) composite material was prepared for anode material of high-capacity lithiun-ion battery. Hollow silica (HSiO₂) was synthesized by the Stöber method with CTAB (N-Cetyltrimethylammonium bromide). The HSi/C anode composite was manufactured by carbon coating after magnesiothermic reduction of HSiO₂. The physical and electrochemical characteristics of the prepared anode materials were investigated based on CTAB amount. In the FE-SEM analysis, it was found that the HSiO₂ particle size increased as CTAB amount decreased, but shell thickness decreased. The HSi/C composites exhibited high initial discharge capacities of 1866.7, 2164.5 and 2188.6 mAh/g with various CTAB ratios (0.5, 1.0, 1.5), respectively. After 100 cycles of charge-discharge, 0.5-HSi/C demonstrated a high reversible capacity of 1171.3 mAh/g and a capacity retention of 70.9%. Electrochemical impedance spectroscopy (EIS) was employed to analyze the impedance characteristics, and it revealed that 0.5-HSi/C showed more stable resistance characteristics than HSi/C composites with other CTAB amount over 20 cycles.

• 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.

• 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.

• Applied Chemistry for Engineering
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• v.32 no.1
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• pp.110-116
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• 2021

In this work, the surface of hydrophilic cellulose nanofibrils (CNFs) was modified precisely by varying amounts of cetyltrimethylammonium bromide (CTAB) to produce CNF-based particle surfactants. We found that a critical CTAB density was required to generate amphiphilic CTAB-grafted CNF (CNF-CTAB). Compared to pristine CNF, CNF-CTAB was highly efficient at stabilizing oil-in-water Pickering emulsions. To evaluate their effectiveness as particle surfactants, the surface coverage of oil-in-water emulsion droplets was determined by changing the CNF-CTAB concentration in the aqueous phase. Furthermore, styrene-in-water stabilized by CNF-CTAB surfactants was thermally polymerized to produce CNF-stabilized polystyrene (PS) particles, offering a great potential for various applications including pharmaceuticals, cosmetics, and petrochemicals.