Cetyltrimetylammonium Bromide Research Articles

Electrode material for high performance symmetric supercapacitors based on superparamagnetic Fe3O4 nanoparticles modified with cetyltrimetylammonium bromide

A facile preparation method is reported to develop a supercapacitance material with high specific capacitance and stability. Fe3O4 superparamagnetic material was synthesised via CTAB assisted co-precipitation method to modify the morphology. Presence of CTAB has resulted in excellent output in terms of high specific capacitance of 1192 F/g at a current density of 1 A/g. 93% of charge storage capacity was retained by the working electrode after 4000 charge-discharge cycles with the optimum concentration of CTAB. The TEM micrograph showed a quasi-spherical morphology for the bare Fe3O4 and the same was modified to semi-cuboidal shape after CTAB modification. The change in crystal lattice was confirmed through SAED in parallel to the WAXRD analysis. The phase purity was deciphered using XPS and surface roughness of the electrode was studied using AFM. Increased saturation magnetisation value for CTAB modified Fe3O4 was also in line with the improved charge storage capacity.

Soft nanocarriers for new poorly soluble conjugate of pteridine and benzimidazole: Synthesis and cytotoxic activity against tumor cells

New conjugated derivative of pteridine and benzimidazole, 7-(benzimidazol-2-yl)-6-(2,4-dichlorophenyl)-2-thioxo-2,3-dihydropteridin-4(1H)-one (BP) possessing antitumor activity was obtained and thoroughly characterized; its spectrophotometry control in solution was developed. To improve the solubility of the hydrophobic antitumor agent BP in aqueous solutions, amphiphilic systems (micellar solutions and modified liposomes) were fabricated, with their composition optimized. Stable 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)-based liposomes modified with cationic surfactants, namely cetyltrimetylammonium bromide and 1-methyl-3-hexadecylimidazolium bromide (IA-16), were obtained. It was shown that the use of cationic surfactants for the formation of hybrid drug carriers and varying of the surfactant/lipid molar ratios can be the key factor for obtaining the optimized particles with high efficiency of encapsulation, favorable loading efficacy and prolonged release of the drug. The most beneficial parameters in terms of stability and loading/release efficacy were obtained for IA-16/DPPC hybrid liposomes with the surfactant/lipid molar ratio of 1:50. Free BP demonstrated cytotoxicity toward M-Hela tumor cells, along with the nearly the same toxic effect toward normal Chang liver cells. Importantly, double effect occurred upon the encapsulation of BP into hybrid cationic liposomes, i.e. a sharp decrease in viability of diseased cells and increase of viability of normal cells. Therefore, liposomal BP formulation can be recommended as therapeutics with improved stability and high selective cytotoxicity toward M-Hela tumor cells at the level of commercial drug doxorubicin, in combination with much less toxicity (by 37 times) toward the normal Chang liver cell line.

Adsorption of Petroleum Fractions on Organo-Modified Calcium Bentonite

This work aims to obtain an organoclay from a local Nigerian bentonite with Cetyl trimetyl-Ammonium bromide (CTAB), a quaternary ammonium compound which possesses surfactant properties. The studied natural bentonite (calcium bentonite) was obtained from Anambra state and modified with CTAB via impregnation techniques. Modification was achieved by varying the concentration of the modifier from 0.02 - 0.15mol/L. Adsorption test was carried out using Water, Petrol (PMS), Kerosene (DPK) and Automotive Gas Oil (AGO) on both modified and unmodified bentonite. The result showed that unmodified bentonite adsorbed more water than hydrocarbons while Modified bentonite adsorbed more hydrocarbons than water. The result also shows that the amount of each hydrocarbon adsorbed increases with an increase in the concentration of the modifier with a subsequent decrease in the amount of water adsorbed. This indicates that the modified bentonite was now organophilic. Therefore, this research shows that the bentonite modified with CTAB can be used in oil spill remediation and also to mop up hydrocarbons from the Environment.

Modification of natural bentonite clay using cetyl trimetyl-ammonium bromide and its adsorption capability of some petrochemical wastes

Modification of natural bentonite clay using cetyl trimetyl-ammonium bromide and its adsorption capability of some petrochemical wastes

Synthesis and Characterization Thermal of Polyurethane/MMT from Castor Oil Polyols for Coating

The purpose of this research overall is the manufacture of polyurethane nanocomposite from castor oil with the addition of montmorillonite nanoparticles as coating material. This study consists of several stages, the manufacture of montmorillonite nanoparticles (MMT), the process of forming polyols from castor oil by epoxidation and hydroxylation reactions with catalysts. The manufacture of polyurethanes (PU) by reacting polyols from castor oil and organic montmorillonite nanoparticles was then characterized and applied to polyurethane nanocomposites as coating materials. Organic montmorillonite nanoparticles are made by an intercalation process with cetyl trimetyl ammonium bromide (CTAB). Polyurethane nanocomposite was prepared by adding organic montmorillonite nanoparticles in polyols before being mixed with toluene diisocyanate. The effectiveness of polyurethane nanocomposites as heat-resistant coatings was determined by thermal properties with thermo gravimetric analysis (TGA) equipment, then the adhesive strength was tested and the morphological properties of the material coating. The manufacture of polyurethane nanocomposite from castor oil as a film coating is applied to material and characterization.

Optimizing Genomic DNA Isolation and PCR Amplification For Pasak Bumi (Eurycoma longifolia)

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Vesicle formation in aqueous mixture of the cetyltrimetylammonium bromide and an anionic chitosan derivative

ABSTRACTThe present work aimed at research the physic-chemical properties of the interaction of N-decyl-O-chitosan sulfate (an amphiphilic chitosan derivative, C10-OCHS) with cetyltrimetylammonium bromide (CTAB) by the steady-state fluorescent, static/dynamic surface tension, turbidity and transmission electron microscopy (TEM). The results showed that the complex of C10-OCHS/CTAB had high surface activity and lower critical aggregation concentration. Besides, the C10-OCHS/CTAB could self-assemble into various aggregates like irregular spherical aggregates, vesicles or polydisperse aggregates from lower to higher concentrations of CTAB with a mixed C10-OCHS concentration of 200 mg/L.

Synthesis of a high surface active polymeric surfactant based on chitosan and characteristics of complexation with cetyltrimetylammonium bromide

ABSTRACTThe N-dodecyl chitosan sulfate (NDCS) with a higher degree of substitution of dodecyl was synthesized. The surface tension and transmission electron microscopy showed that the product had a higher surface activity and could self-assemble into bigger spherical polymeric micelles. Besides, the characteristics of complexation of NDCS with cetyltrimetylammonium bromide (CTAB) were studied by static/dynamic surface tension, turbidity and transmission electron microscopy. The results revealed that the mixture of NDCS with CTAB had a higher surface activity, lower diffusing rate and higher turbidity. Furthermore, they also could self-assemble into agglomerate or dispersed spherical aggregates in some concentration domain of CTAB.

The supramolecular approach to the phase transfer of carboxylic calixresorcinarene-capped silver nanoparticles

The octacarboxylic derivative of tetrapentylcalix[4]resorcinarene (1) was used as stabilizer for preparation of silver nanoparticles (AgNPs) hydrosol. The calixresorcinarene-capped nanoparticles Ag@1 are stably dispersed in an aqueous colloid solution and have an average diameter of 4–6nm (TEM). The interaction of the macrocycle 1, possessed the receptor properties, with the cationic surfactant cetyltrimetylammonium bromide (CTAB) leads to the hydrophobization of AgNPs hydrosol. It was shown, that macrocycle 1 in its individual solution forms the hydrophobic associate with 8mol of CTAB (1H NMR, 2D NOESY). Various and complicated influence of CTAB/macrocycle molar ratio on the hydrophobization of AgNPs and their transfer into organic phase was demonstrated. The initial Ag@1 and modified Ag@1-CTAB were characterized by UV-vis and FTIR spectroscopy, DLS, and TG/DSC methods It was shown that the efficiency of water/organic phase transfer depends on the macrocycle/surfactant molar ratio. The presented supramolecular approach can be useful to form the ordered nanostructures through supramolecular modification and self-organization of hybrid metal nanoparticles.

Surface, compressibility and viscometric measurements of binary system containing cationic surfactant with achiral amino acid at different temperatures

In the preset manuscript, we intend to examine the type of solute-solvent interactions present in such system which is valuable to food/pharmaceutical sector. A systematic knowledge of the volumetric properties in conjunction with other thermodynamic properties provides useful information about water-solute interactions. We examine, therefore, surface tension, density, speed of sound and viscosity for binary system contains cationic surfactant cetyltrimetylammonium bromide (CTAB) in aqueous glycine solution (0.2, 0.3 and 0.4) mol/kg at four different temperatures ranging from (298.15 to 313.15) K. The surface tension result indicates the change in critical micelle concentration (CMC) values in the presence of additive. Various thermodynamic and adsorption parameters like surface excess, Γmax, minimum area at air-liquid interface, Amin etc. have been evaluated form surface tension data. The density and speed of sound measurements have been used to calculate the apparent molar volume and adiabatic compression which reveals the kind of interactions present pertaining to hydrophilic-hydrophillic and ion-hydrophillic interactions. In addition, hydrophobic hydration also plays a key role especially at higher surfactant concentration. Viscosity data further strengthen the concept of hydrophobic interactions present in the binary solution taken into consideration the relative viscosity and viscous relaxation time parameters. The effect of temperature and additive for all the calculated parameters has also been discussed in detail.

STUDY ON FORMULATION OF POLYURETHANE/CLAY NANOCOMPOSITES BASED ON PALM OIL POLYOL

A novel segmented polyurethane/clay nanocomposites has been synthesized by polyurethane based on palm oil and Kunipia-F as organoclay with an ammonium salt of cetyltrimetyl ammonium bromide (CTAB). In this investigation, we give much interest to synthesis of polyurethane/clay based on palm oil as raw materials for polyols to open new era for partial replacement of petrochemical based polyol with palm oil based polyols. Surprising, we got the polyurethane elastomer after along time polyurethane based on palm oil only using in coating applications. However, it is the first report in investigation about polyurethane/clay nanocomposites based on palm oil. Polyurethane/clay nanocomposites were prepared by a pre-polymer method and evaluated by fourier transform infrared spectra (FTIR) and X-ray diffraction measurements (X-RD) respectively.Keywords : Nanocomposite, polyurethane, synthesis, palm oil

Molecular dynamics simulations of various micelles to predict micelle water partition equilibria with COSMOmic: Influence of micelle size and structure

Due to the large number of different surfactant and solute molecules used in micellar solutions, it is important to have predictive models for micelle-water partition equilibrium. The relative new method COSMOmic, an extension of COSMO-RS, can predict thermodynamic data by taking the anisotropy of a system into account. For this purpose, it needs the structure of the system in atomistic resolution. In previous studies, atomic distributions were obtained from self-assembly molecular dynamics (MD) simulations. In this work MD simulations starting from pre-assembled micelles are used to receive atomic distributions. These simulations are more efficient than self-assembly simulations with respect to system size and simulation time and allow the detailed study of micelle size/structure influences on solute partitioning. For the first time a wide range of aggregation numbers for different types of surfactants are investigated. More than 90 different micelles structures were obtained for six different surfactants: SDS (sodium dodecyl sulfate), CTAB (cetyltrimetylammonium bromide), C12E10, Brij35 (C12E23), Triton X-114 and Triton X-100 with initial aggregation numbers between 20 and 160. These were investigated with respect to micelle size, micelle shape, surfactant concentration and simulation time. To examine the prediction quality of COSMOmic, experimental data was collected and 36 micelle-water partition coefficients for C12E10, Triton X-100 and Brij35 were measured. In total more than 370 experimental partition coefficients were used to validate the calculations. The results show that the calculations are in good agreement with the experimental data and that they are better than predictions from methods that do not take the micelle structure into account (pseudo phase approach). In this context, small spherical micelles are proven to be more efficient while larger more ellipsoidal micelles show a higher probability to result in outliers. Therefore, this article provides a guideline for the development of averaged atomic distributions as input for COSMOmic.

EFFECT OF STIRRING RATE ON ELECTROCHEMICAL CODEPOSITION OF Ni-SiC COMPOSITE

Nickel-Silicon Carbide (Ni-SiC) composite has been prepared by electrochemical codeposition technique. Nickel sulfamate bath was used along with grain modifier saccharine and cationic surfactant cetyltrimetylammonium bromide (CTAB). The effect of stirring rate was systematically studied and optimized to get well dispersed SiC particles in appropriate amount. Mixed crystalline phase with reinforced [2 1 1] crystal orientation was obtained by XRD analysis. The result revealed that, 250 revolutions per minute (rpm) is optimum stirring rate for the electrochemical codeposition of Ni–SiC. Coating prepared at 250 rpm showed highest microhardness and lowest coefficient of friction with better surface morphology and well distributed nano SiC particles.Scientific World, Vol. 12, No. 12, September 2014, page 30-33

Preparation, Characterization and Catalytic Activity of Sulfated Zirconia by Varied Sol-Gel Method

The sulfated zirconia catalysts were was prepared by sol–gel processes consist of varied templating method. Both preparations consist of sol-gel synthesis of zirconium dioxide followed by sulfatation process by using NH4SO4 solid reaction method. Two different templating agent; urea and cetyltrimetyl ammonium bromide was used in sol-gel processes. The prepared material was characterized using scanning electron microscope (SEM), x-ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) measurements. From the XRD measurement it can be concluded that both materials consist of ZrO2 in combined phases while from BET surface area analysis it can be noted that material prepared by urea template has higher specific surface area compared to that use CTAB template. Both materials exhibit the activity as acid catalyst in microwave assisted conversion of citronellal. It is also confirmed that the higher the surface area the higher total conversion of citronellal obtained. Study on the correlation between physicochemical properties of materials with the catalytic activity was discussed in this paper.

Preparation of Dichlorocarbene Modified Butadiene Rubber and Its Thermal Properties

SummaryDichlorocarbene modified butadiene rubber (DCBR) was prepared from butadiene rubber (BR) via an alkali hydrolysis of chloroform with using cetyltrimetylammonium bromide (CTAB) as a phase transfer agent. The chemical structure of DCBR was characterized by a fourier transform infrared spectroscopy and 1H‐ and 13C‐nuclear magnetic resonance spectroscopy. The chlorine content in DCBR matrix was extracted by acid digestion method and estimated based on a volhard method. The chlorine content of DCBR increased with the increase of reaction time. The glass transition temperature (Tg) of DCBR (Tg = −3.4 °C) was shifted to the higher temperature compared to Tg value of BR (Tg = −102.8 °C) due to the presence of dichlorocarbene group. Moreover, thermogravimetric analysis was used to study the decomposition profile of BR and DCBR. The thermal stability of DCBR was decreased compared to that of BR, while the flame retardant of NR/DCBR blend was improved due to the presence of chlorine in DCBR. The chlorine char from dichlorocarbene group acted as a thermal insulator for rubber.

Solubilization of new calix[4]resorcinols with amino acid substituents at the upper rim in surfactant micellar solutions

A spectrophotometric method was used to select conditions for the development of aqueous systems based on new calix[4]resorcinols containing amino acid moieties at the upper rim and heptyl or nonyl substituents at the lower rim. It was found that the additives of N-metylglucamine lead to the increase in the solubility in water of the macrocycles under study. Traditional surfactants (cetyltrimetylammonium bromide and sodium dodecylsulfate) considerably increase the solubility of calix[4]resorcinols under study due to their solubilization in the nonpolar micelle core when the concentration of the amphiphilic compounds is half as large as the concentration of N-metylglucamine.

Effect of Surfactant on the Thermal Behavior of Cerate-Zirconate Ceramic Powder Prepared by Modified Sol-Gel Method

BaCe0.54Zr0.36Y0.1O2.95 (BCZY10) ceramic powder was synthesized by a modified sol-gel method using metal nitrate salt as pre-cursors. The sample was prepared using three different types of surfactants namely polyethylene glycol (PEG) 6000, sodium dodecyl sulphate (SDS) and cetyltrimetylammonium bromide (CTAB). Thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectrometry was used to analyze the thermal decomposition of the dried (T=325 °C) and calcined (T=1100 °C) powder. Standard sample prepared without surfactant is denoted as A1 while the sample that prepared using PEG, SDS and CTAB as surfactant was denoted as A2, A3, and A4 respectively. TGA results indicate that all the samples were almost completely decomposed at ~800 °C except for A2. It showed the lowest thermal decomposition temperature Ttd=739 °C. The highest total weight loss ~94.7% is shown by sample A4 than others. The sample with the presence of surfactant exhibits faster reaction rate for the first decomposition stage which is t = 8 min, 11 min, and 13 min for sample A2, A3, and A4 respectively compared to A1 (t = 18 min). The A2 sample shows faster reaction rate indicates that BCZY10 compound might be formed earlier faster due to the long carbon chain posses by PEG surfactant. The higher number of carbon chain present in the surfactant may accelerate the combustion process and the formation of metal oxide compounds. FTIR spectra illustrated that the carbonate residue still remained in all the samples even after calcined at 1100 oC. This result indicates that the used of surfactant does not give a significant effect on preventing the formation of BaCO3. However, the intensity of metal-oxygen band at ~450 cm-1 become stronger indicates that the formation of BCZY10 compound was being enhanced.

Experimental study on the adsorptive behavior of Congo red in cationic surfactant-modified tea waste

The adsorption of Congo red (CR), an anionic dye, from aqueous solution by a cationic surfactant-modified tea waste (TW) was studied in batch experiments. Cetyl trimetyl ammonium bromide (CTAB) and cetyl pyridinium bromide (CPB) was used for the modification of TW and ground TW. CTAB-modified TW exhibited the highest adsorption capacity with respect to the other prepared adsorbents. The adsorption of CR on CTAB-TW as a function of adsorbent dosage, pH of the solution, contact time, and initial dye concentration was investigated. The optimum amount of CTAB-TW was found to be 0.2g. The equilibrium CR adsorption data on CTAB-TW were best described by the Langmuir isotherm model. The adsorption capacity of CR on CTAB-TW was found to be 106.4mg/g which is relatively high with respect to the other adsorbents. The adsorption kinetics of CR on CTAB-TW followed a pseudo-second-order model. Moreover, the intraparticle diffusion model was used to describe the kinetic data. It was found that diffusion is not the only rate controlling step. The adsorbent was characterized by the Brunauer–Emmett–Teller (BET) analysis, Fourier-transform-infrared (FTIR) spectroscopy, and scanning-electron-microscopy (SEM). The mechanism for the adsorption of CR on the surfactant modified TW may include hydrophobic interaction, van der Waals interaction, π–π stacking and electrostatic interaction.

Intensification of drag reduction effect by simultaneous addition of surfactant and high molecular polymer into the solvent

The paper presents the analysis of the possibilities of intensification of drag reduction effect (DR) by simultaneous addition of non-ionic high molecular polymer – poly(ethylene oxide) and the cationic surfactant – cetyltrimetyl ammonium bromide into the solvent. Salt sodium salicylate was applied as a counter-ion. The analyzed solutions were compared with their pure polymer or micellar equivalents.Clear existence of three drag reduction zones was observed: stable transitional zone, unstable transitional zone and in particular the third turbulent drag reduction zone. The dominant factor which influenced DR in the transitional zone was the addition of CTAB+NaSal. In the third zone, the addition of PEO had decisive influence on the DR intensity. The increase of PEO concentration enhanced DR in this zone.The influence of pipes diameter on the DR was investigated. The increase of pipe diameter caused clear extension of the stable transitional zone. In the third zone DR increased while decreasing pipe diameter.Analyses showed that the value of the n flow index was not an important factor in the DR.The results indicate that polymer-micellar solutions combine and intensify positive features of their pure polymer and micellar equivalents, providing efficient DR in a wider range of the Reynolds numbers.

Effect of Co Doping on the Properties of Ce0.75Zr0.25O2 Nanocatalyst

5wt% Co deposited on a support catalyst Ce0.75Zr0.25O2 mixed oxide were prepared by combination of microemulsion and deposition-precipitation method followed by calcinations at temperature 500°C. The microemulsion component comprise of cetyl trimetyl ammonium-bromide (CTAB), 1-butanol, n-octane and aqueous solution. Sodium hydroxide (NaOH) was used as precipitation precursor for the preparation of water-in-oil microemulsions method. The particles were characterized by X-ray diffraction (XRD), N2 adsorption-desorption analysis and Field Emission Scanning Electron Microscopy (FESEM). The results showed the preparation method has significant influences on the textural and structure properties of Co/Ce0.75Zr0.25O2. The formation of Co/Ce0.75Zr0.25O2 inhibit the better performance based on the particles size, specific surface area and particle distribution of cobalt into Ce0.75Zr0.25O2.