Effect Of Cetyltrimethylammonium Bromide Research Articles

Effect of CTAB and SDS on base hydrolysis of iron(II)-sulphonated and unsulphonated phenyl-1,2,4-triazine complexes - A kinetic and mechanistic study

The effect of cetyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulphate (SDS) on base hydrolysis of iron(II)-triazine complexes viz., tris((3-(4-phenyl)-2-pyridyl)-5,6-bis(4-phenyl)-1,2,4-triazine)iron(II), Fe(PPDT)32+ and its sulphonated analogue, tris(3-(4-(4-phenylsulphonic acid)-2-pyridyl)-5,6-bis(4-phenyl sulphonic acid)-1,2,4-triazine)iron(II), Fe(PPDTS)37‐ has been studied under pseudo-first order conditions at 25, 35, 45 and 55°C. These reactions are first order with respect to the substrate and hydroxide ion. The rate of base hydrolysis of Fe(PPDT)32+ decreases with the increase in ionic strength in both aqueous and CTAB media whereas the effect is minimal in SDS medium. In the case of Fe(PPDTS)37‐, the opposite is seen i.e., the rate of hydrolysis increases with the increase in ionic strength in both the aqueous and SDS media whereas in CTAB medium it has little effect. Specific rate constants (k2) and activation parameters, Ea, ΔH#, ΔS# and ΔG# have also been evaluated. The results obtained suggest that these reactions occur essentially by the same mechanism in aqueous and micellar media. About 104 times catalysis and 5 times inhibition were noticed in CTAB and SDS media respectively when compared to aqueous medium. The observed catalysis is ascribed to electrostatic and hydrophobic interactions between hydroxide and CTAB ions, whereas the inhibition is attributed to the electrostatic repulsions between hydroxide ion and dodecyl sulphonate anions. Density functional theory (DFT) calculations were found to support the experimental results.

The study of interfacial tension of kerosene-water under influence of CTAB surfactant and different size silica nanoparticles

Kerosene–water system is widely used in liquid–liquid extraction investigations. This study aimed to examine the effect of cetyltrimethyl ammonium bromide (CTAB) surfactant and different size silica nanoparticles (NPs) on the interfacial tension (IFT) of kerosene–water at 298.2K and ambient pressure. Based on the experimental results, CTAB with concentrations up to 5.0×10−4moldm−3 was positively adsorbed while no sensible adsorption was observed in the case of NPs alone. However, the surfactant adsorption could significantly improve in the presence of only 1.00×10−4wt% of NPs, leading to a significant decrease in the IFT. In addition, aqueous phase pH variation indicated strong effects under alkaline pHs. The obtained experimental IFT data for CTAB concentrations were considerably reproduced by the well-known Frumkin adsorption isotherm under the critical micelle concentration. Accordingly, a decrease was appeared in the saturated interface excess with pH while adsorption equilibrium constant could increase. Finally, both higher saturated interface excess and lower adsorption equilibrium constant were recognized as appropriate for the larger size NPs.

Effect of cetyltrimethyl ammonium bromide on uptake of polycyclic aromatic hydrocarbons by carrots

This is the first study investigating the effect of cationic surfactants on the mobility of polycyclic aromatic hydrocarbons (PAHs) in aged contaminated soils and on PAH bioaccumulation in tuberous vegetables. In an aerobic soil incubation experiment, 150 mg/kg cetyltrimethyl ammonium bromide (CTMAB) decreased the bioavailability of PAHs primarily via immobilization (by 13%). In a carrot pot experiment, the effectiveness of CTMAB to reduce PAH uptake by carrots decreased with time. Accordingly, the bioavailability of PAHs in the soil decreased in the first 90 days and then increased and remained stable until harvest. In the leaching test, the leaching loss of CTMAB (15%) was lower in soils treated with small amounts of CTMAB in several applications than it was in soils (24%) treated once with CTMAB. Therefore, CTMAB, when applied in appropriate doses via addition methods, can effectively reduce the environmental risk of PAH entering humans and livestock through the food chain.

Effect of CTAB on structural and optical properties of CuO nanoparticles prepared by coprecipitation route

CuO (Copper Oxide) nanoparticles were synthesized by a simple coprecipitation route by using copper acetate, sodium hydroxide as precursors and cetyltrimethyl ammonium bromide (CTAB) as surfactant. For the purpose of the study, the surfactant-CTAB treated and non-treated samples were synthesized separately. Both the synthesized samples were studied to understand their structural and optical properties. The formation of CuO and its crystallinity was confirmed by XRD. Further, the optical studies showed a defined blue shift in CTAB treated sample which is clear evidence that the particles undergo confinement when they are nano-regime.

Effect of cetyltrimethylammonium bromide and its gemini homologue bis(cetyldimethylammonium)butane dibromide on activity of xanthine oxidase

ABSTRACTSpectrophotometry is employed to study the effect cetyltrimethylammonium bromide (CTAB) and bis(cetyldimethylammonium)butane dibromide (C16C4C16Br2) on the activity of xanthine oxidase (XO), a key enzyme in purine metabolism, at pH 7.4 and 25°C. The spectrophotometric results revealed that the Gemini surfactant interact strongly with the XO than its conventional single chain counterpart and unfold it to a greater extent as compared to CTAB. The effectiveness of the Gemini in interacting/unfolding the XO are justified owing to peculiar structural features of C16C4C16Br2 owing to the presence of two charged headgroups and two hydrophobic tails and hence enhanced competence for electrostatic and hydrophobic interactions.

In Ukrainian

The effect of cetyltrimethylammonium bromide (CTAB) on drying patterns of aqueous suspension of multiwalled carbon nanotubes (NTs) has been studied. The sessile droplets were dried on glass substrates in an air bath chamber (295±0.1 K) with fixation of changes in transparency using an optical microscope CAM-03 (Sigeta, China). The relative humidity in the chamber was of 40 ± 5%. The concentrations of NTs and CTAB were changed in the ranges of C n = 0.005-0.1% and C s = 0.0-0.1%, respectively. The final drying patterns were tested using analysis of radial distribution of optical transparency, and the topographies of patterns were investigated using an atomic force microscope (AFM) NanoScope IIIa Dimension 3000 (Digital Instruments, Bruker, USA). In bulk aqueous suspensions addition of CTAB improved dispersion of NTs and at x=C s /C n >=0.1 the size of NT aggregates progressively decreased. The formation of drying patterns with four different morphological types was observed as dependent on the concentrations of NTs and CTAB. The increase of CTAB concentration resulted in increase of the thickness of a “coffee ring”. For different concentrations of NTs the similar correlations in the behaviour of total transparency of drying pattern and thickness of the "coffee ring" layer were observed. The data obtained using the AFM technique indicated the possibility of formation of quite thick bundles of NTs located inside the "coffee ring" layer.

Effects of cetyltrimethylammonium bromide on the morphology of green synthesized Fe3O4 nanoparticles used to remove phosphate

In this paper, iron oxide nanoparticles (IONPs) are successfully synthesized using Eucalyptus leaf extract in the presence of cetyltrimethylammonium bromide (CTAB) to enhance the dispersion and reduce aggregation of IONPs. CTAB was used as a stabilizing and capping agent in biosynthesis of IONP was observed. The particle size decreased from 183.9±30.1nm to 89.8±17.1nm as the concentration of CTAB increased from 0 to 0.4mM CTAB, indicating that CTAB reduce the aggregation of IONPs and enhance the reactivity. In addition, the removal efficiency of phosphate declined from 95.13% to 89.58% when the CTAB concentration increased from 0.4 to 10mM, indicating that a CTAB impacted on micelles and lipophilic biomolecules in Eucalyptus leaf extract, and hence affected the formation of IONPs. Furthermore, SEM image showed that the smaller spherical with some irregularly shaped CTAB-IONPs having a diameter of 80–90nm in the presence of 0.4mM CTAB were observed. The date from EDS, FTIR and TGA suggested that the CTAB capped on the surface of CTAB-IONPs, while XRD showed that zero-valent iron and iron oxide were formed. Finally, the formation mechanism of IONPs was proposed.

The effect of cetyltrimethylammonium bromide on the coefficient of thermal expansion and optical transmittance of poly(ether sulfone) film

Cetyltrimethylammonium bromide (CTAB) was used as a stabilizing agent for PES films, and its effect on the coefficient of thermal expansion (CTE) and optical transmittance (OT) of PES films was investigated. The CTE of PES film decreased with increasing CTAB concentration up to 0.5 wt%, because of the improved intermolecular interaction between polymer chains via CTAB molecules. When 0.5 wt% of CTAB was added to the PES film, the CTE of polymer film decreased from 66 to 50 ppm/°C without noticeable reduction in OT. At such a low CTAB concentration range (<0.5 wt%), the glass transition temperature (T g ) and tensile strength increased with CTAB. At high CTAB concentration above 0.5 wt%, however, it had a negative effect on the properties of PES film - CTE increased but T g and tensile strength decreased with it.

Cationic surfactant (CTAB) a multipurpose additive in polymer-based drilling fluids

Drilling fluids are designed to assist drilling by minimizing reservoir damage and increasing productivity of pay zone. Excess fluid loss due to degradation of additives of drilling fluids causes a major problem in real-time drilling. Usages of excess biocides are threat to the environment and cause handling problems. Effect of cetyltrimethylammoniumbromide, a cationic surfactant, on rheology, fluid loss and biocide has been studied in a polymer-based drilling fluid. Inhibitive polymer mud was formulated using XC polymer, shale inhibitors like KCl, K2SO4 and CaCO3 as bridging agent. Rheology and other properties were studied using Fann VG meter, API filter press, mud balance, roller oven apparatus. Dissolved oxygen meter was used to check the microbicidal property of cetyltrimethylammoniumbromide. Addition of cetyltrimethylammoniumbromide increased fluid retention capacity of the fluid even at very low concentration 0.1%(w/v) without affecting the mud properties. Also it is compatible with the commercially available fluid loss preventers like pre-gelatinized starch when used in combination. It also performed well in dissolved oxygen test, suggesting eliminating need of any other biocide to prevent degradation of bio-polymer-based drilling fluid. The dissolved oxygen test results are comparable with commercial available biocides. Thermal stability studies were carried out by using roller oven at different temperatures. It was found suitable for application in high-concentrated brine conditions and at high temperatures up to 120 °C without effecting the rheology and shear thinning property of the fluid. Bridging efficiency was investigated by analysing the mud cake using scanning electron microscope.

Effects of cetyltrimethylammonium bromide (CTAB) on the structural characteristic of non-expandable muscovite

The non-expandable muscovite was treated with an alkaline salt and modified with cetyltrimethylammonium bromide (CTAB) at various concentrations in a cation exchange reaction. Basal spacing, interlamellar structure, morphological structure, and specific surface area (SSA) of this organomuscovite were characterized using X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FTIR), field emission scanning electron microscopy (FESEM) coupled with energy dispersive X-ray spectroscopy (EDX) and the Brunauer–Emmett–Teller (BET) method. The increase in basal spacing and SSA following lithium nitrate (LiNO3) treatment and organic modification indicates that natural muscovite can be expandable as the number of stacked individual layers keeps decreasing at high CTAB concentrations as suggested by XRD and BET. The appearance of symmetric and asymmetric stretching vibrations in FTIR analysis indicated the presence of the surfactant in muscovite layers. The FESEM organomuscovite formation images confirm the presence of intercalated structures. The present study shows that not only the basal spacing, but also the specific surface area and the number of the stacked individual silicate layers of the organoclay strongly depend on the packing density of the surfactant within the muscovite interlayer space.

Effects of Cetyltrimethylammonium Bromide and Heptane on the Surface Properties and CO2 Adsorption of Zeolite NaX

Zeolite X was synthesized by the gelation method for use as a CO2 adsorbent. The zeolite was prepared from a sodium silicate solution and Al(OH)3 as silicon and aluminum source, respectively. The effects of cetyltrimethylammonium bromide (CTAB) and heptane addition on surface properties, morphology, and CO2 adsorption capacities were investigated. The CO2 adsorption capacity of the synthesized zeolite with the addition of CTAB and heptane increased as demonstrated by the higher CO2 uptake (3.00 mmol/g), which was due to the higher surface area and pore volume. Interaction between CTAB micelles and sodium cations with aluminosilicate anions led to an increase in the nucleation rate and smaller crystalline sizes. The addition of heptane resulted in higher positively charged CTAB micelles and improved the affinity between the micelles and aluminosilicate anions.

Double-Shelled TiO2 Hollow Spheres Assembled with TiO2 Nanosheets.

High-quality double-shelled TiO2 hollow spheres (DHS-Ti) assembled with TiO2 nanosheets have been synthesized for the first time through a simple hydrothermal treatment of sSiO2 @TiO2 (TiO2 -coated solid SiO2 spheres). The double-shelled structure shows a high BET surface area up to 417.6 m2 g-1 . Anatase DHS-Ti of high crystallinity can be obtained without structural collapse by calcination treatment. The effects of cetyl trimethylammonium bromide (CTAB) concentration, pH, and hydrothermal reaction temperature have also been investigated with a series of contrast experiments. A formation mechanism involving the in situ growth of amorphous TiO2 nanosheets followed by the redeposition of dissolved silica species is proposed. Lastly, the DHS-Ti forming strategy can be extended as a general strategy to fabricate various morphological hollow nanostructures and double-shelled Pt nanocatalysts by rationally selecting functional sSiO2 nanoparticles as core materials. This work could open up a new strategy for controllable synthesis of complex hollow structures and other functional materials.

Inhibitory effect of cetyltrimethyl ammonium bromide on the corrosion of 904L stainless steel in LiBr solution

The inhibitory influence of cetyltrimethyl ammonium bromide (CTAB) on 904L stainless steel (SS) in LiBr solution was investigated by potentiodynamic polarisation, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy techniques. The results showed that the inhibition efficiency of CTAB increases with the increasing concentration. The adsorption of CTAB on 904L SS surface obeys the Langmuir isotherm equation. The data reveal that the CTAB was of mixed-type inhibitor. The thermodynamic parameters for the corrosion of 904L SS in 1.0 M LiBr solution were calculated and discussed. The EIS data are in agreement with potentiodynamic polarisation measurements.

The influence of aggregation of latex particles on membrane fouling attachments & ultrafiltration performance in ultrafiltration of latex contaminated water and wastewater

The goal of the present study was to investigate the influence of latex particle aggregation on membrane fouling attachments and the ultrafiltration performance of simulated latex effluent using Cetyltrimethyl Ammonium Bromide (CTAB) as a cationic surfactant. Hydrophilic polysulfone and ultrafilic flat heterogeneous membranes, with molecular weight cut off (MWCO) of 60,000 and 100,000, respectively, as well as hydrophobic polyvinylidene difluoride with MWCO of 100,000, were used under a constant flow rate and cross-flow mode in ultrafiltration of latex solution. In addition, a polycarbonate flat membrane with uniform pore size of 0.05μm was likewise used during the experiment. The effects of CTAB on the latex particle size distribution were investigated at various concentrations, different treatment times, and diverse agitation duration times. The effects of CTAB on the zeta potential of membrane surfaces and latex particles were also investigated. The data obtained indicate that the particle size distribution of treated latex effluent experienced significant shifts in the peaks toward a larger size range caused by the aggregation of particles. As a result, the mass of fouling contributing to pore blocking and the irreversible fouling were noticeably reduced. The optimum results occurred in the instance when CTAB was added at the critical micelle concentration of 0.36g/L, for the duration of 10min and with minimal agitation. Notably, a higher stirring rate had an overall negative effect on the membrane fouling minimization.

Effect of Cationic Surfactant Micelles on Hydroxyapatite Nanocrystal Formation: An Investigation into the Inorganic–Organic Interfacial Interactions

To clarify hydroxyapatite (HAp) nanocrystal formation based on the interfacial interactions with organic molecules is important for controlling the dispersion states/shapes of HAp and understanding the biomineralization mechanism. In this study, the effects of cetyltrimethylammonium bromide (CTAB) micelles on the HAp nanocrystal formation process were investigated through both the morphosynthesis technique and the molecular orbital calculations. The HAp nanocrystals synthesized in the presence of CTAB exhibited a controlled rod-like shape and subsequently grew up by a thermal treatment to be larger-sized nanocrystals at a well-dispersed state. It was also found that the CTAB micelles strained and disordered at the higher temperature effectively induced heterogeneous nucleation to initiate the nucleation/growth processes. In contrast, HAp nanocrystals synthesized without CTAB exhibited irregular-shaped and aggregated nanocrystals, which are due to dominantly occurring homogeneous nucleation. According to t...

The self-assembly of twinned boehmite nanosheets into porous 3D structures in ethanol–water mixtures

Surfactant molecules have high surface activity, and can therefore influence the self-assembly of nanomaterials. The self-assembly of twinned boehmite nanosheets into porous 3D superstructures will be greatly affected by the presence of surfactant monomer and micelles in various ethanol–water mixtures. It should be possible to influence the shape, thickness, and twinning of boehmite nanosheets by varying the concentration of the surfactant and ethanol in the synthesis mixture to obtain high porosity 3D superstructures. The critical micelle concentration (CMC) of cationic surfactant cetyl trimethylammonium bromide (CTAB) was determined in 0, 12.5, 25, 37.5, and 50 vol% ethanol–water mixtures. The effect of CTAB on boehmite particle morphology and superstructure formation during self-assembly was explored at the CMC, and at 20%, 15%, 10%, 5% below and above the CMC of CTAB in various ethanol–water mixtures. Boehmite nanosheets with controllable shape and thickness were successfully formed in various ethanol–water mixtures. Prior to micelle formation, the average thickness of nanosheets formed in 0 vol%, 25 vol%, and 50 vol% ethanol–water were 200 nm, 110 nm and 100 nm, respectively. Micelle formation reduced the availability of surfactant molecules for particle templating, broadening the nanosheet thickness distribution. Micelle formation was inhibited in 50 vol% ethanol–water due to the increase in Gibbs free energy needed to form micelles relative to the Gibbs free energy of micelles in 0 vol% or 25 vol% ethanol–water. The enthalpy-driven process gives greater control over the nanosheet thickness, producing particles with narrow thickness distributions. In general, the CMC represented the point at which control is lost over the thickness of the nanoplatelets; increasing the surfactant concentration above the CMC increased the thickness of the nanoplatelets. Particle twinning during crystal growth produced an interconnected 3D network of boehmite particles with high porosity (79–88%) and hydraulic permeability (62.4–809 mD). The addition of ethanol during synthesis increased the porosity and reduced the bulk density of the 3D superstructures by 8–11% and 26–28%, respectively, and yielded a ten-fold increase in the hydraulic permeability. The integrity of the porous 3D network was maintained upon calcination, suspension in water and deposition by filtration onto cellulose filter paper.

CTAB-Assisted Precipitation Synthesis of Ca(OH)&lt;sub&gt;2&lt;/sub&gt; Sorbent for CO&lt;sub&gt;2&lt;/sub&gt; Captures

Ca (OH)2 sorbent with novel pods bundle structure were successfully synthesized by precipitation method by using Cetyltrimethylammonium bromide (CTAB) as cationic surfactant. The effects of CTAB on the morphologies of Ca (OH)2 sorbent were investigated. The results showed that the presence of CTAB could significantly differ the shape and particle size of the Ca (OH)2 sorbent which synthesized in ethanol media at 35°C for 30 minutes. The XRD pattern indicated that the as-prepared product were well-crystallized hexagonal phase of Ca (OH)2 sorbent. Possible mechanisms for the CTAB assisted particle growth of Ca (OH)2 sorbent are discussed. The Ca (OH)2 sorbent have been studied by thermal gravimetric analyzer (TGA) at a 650oC carbonation temperature. The morphological changes and particle size of the sorbent have greatly influenced the CO2 capture performance.

Tailored smart bioactive glass nanoassembly for dual antibiotic in vitro sustained release against osteomyelitis.

The effect of cetyltrimethylammonium bromide (CTAB) concentration as a sacrificial template on tunable mesostructure textured bioactive glass nanoparticles has been explored and characterized. For the 10 mM CTAB concentration templated sample, smart bioactive glass nanoassembly (nBGA) has been tailored for dual antibiotic sustained release against osteomyelitis disease. The loading of two different drugs on the bioglass has been controlled through a thin chitosan sheath. To our knowledge, for the first time synergistic co-drug delivery of two antibiotics, namely sodium ampicillin and gentamicin sulfate, through bioglass nanoassembly, along with bone regeneration has been considered. Sustained co-release kinetics of dual anti-biotic drugs at different time points was evaluated. In addition to this, the in situ loss in bacterial viability with time of the dual drug loaded bioglass nanoassembly has been quantified against two different mono- and co-bacterial cultures by live/dead BacLight bacterial viability kit. Additionally, osteoblast like osteosarcoma cells proliferation on the dual drug loaded bioglass nanoassembly surface has been quantified in the presence and absence of bacterial challenge. This study provides a new insight into the application of bioactive glass as an efficient co-drug delivery vehicle for osteomyelitis.

CTAB enhancement of FRET in DNA structures.

The effect of cetyl-trimethylammonium bromide (CTAB) on enhancing the fluorescence resonance energy transfer (FRET) between two dye-conjugated DNA strands was studied using fluorescence emission spectroscopy and dynamic light scattering (DLS). For hybridized DNA where one strand is conjugated with a TAMRA donor and the other with a TexasRed acceptor, increasing the concentration of CTAB changes the fluorescence emission properties and improves the FRET transfer efficiency through changes in the polarity of the solvent, neutralization of the DNA backbone and micelle formation. For the DNA FRET system without CTAB, the DNA hybridization leads to contact quenching between TAMRA donor and TexasRed acceptor producing reduced donor emission and only a small increase in acceptor emission. At 50 µM CTAB, however, the sheathing and neutralization of the dye-conjugated dsDNA structure significantly reduces quenching by DNA bases and dye interactions, producing a large increase in FRET efficiency, which is almost four fold higher than without CTAB.

Polypyrrole nanosphere embedded in wrinkled graphene layers to obtain cross-linking network for high performance supercapacitors

Polypyrrole nanospheres were embedded in graphene layers (rGCP) to successfully form three-dimensional hierarchical cross-linking structure through simple hydrothermal method. The structure of rGCP composite mainly resulted from the synergistic effect of cetyltrimethyl ammonium bromide and crumpled graphene layers, which was beneficial for achieving large surface area, short ion diffusion pathway, excellent rate performance and cycling stability. As a result, the hybrid rGCP composite exhibited excellent electrochemical performance with a specific capacitance of almost 400Fg−1 at the scan rate of 1mVs−1. Furthermore, even at the high current density of 10Ag−1, it still retained the capacitance of 243.2Fg−1, and excellent cycling stability (91.8% capacitance retention even after 5000 cycles). The as-prepared hierarchical hybrid composite has promising potential in electrochemical energy storage.