Mixtures Of Cetyltrimethylammonium Bromide Research Articles

Mixed surfactant assisted synthesis of single-crystal Ni2P hollow spheres with excellent adsorption performance

The single-crystal Ni2P hollow spheres have been synthesized via a solvothermal route in presence of mixed surfactant. It is showed that solvent played a significant role for the synthesis of Ni2P. Furthermore, the structure of hollow spheres would be obtained only using the mixtures of cetyltrimethyl ammonium bromide (CTAB) and sodium dodecyl benzene sulfonate (SDBS) which act as soft template rather than single CTAB or pure SDBS. Finally, it turned out that the single-crystal Ni2P hollow spheres exhibit excellent adsorption activity for malachite green (MG) organic dyes.

Regeneration of LiNi0.6Co0.2Mn0.2O2 material from spent lithium-ion batteries by solution combustion synthesis method

LiNi0.6Co0.2Mn0.2O2 (NCM622) material was regenerated by solution combustion synthesis method using metal precursors obtained from the spent lithium-ion batteries. The structural, microstructural, and electrochemical properties of the regenerated cathode material were evaluated as a function of fuel type including citric acid, polyvinylpyrrolidone (PVP), cetyltrimethylammonium bromide (CTAB), and a mixture of CTAB and PVP fuels. The mixed CTAB-PVP fuel led to the layered crystal structure and porous microstructure with high specific surface area and pore volume. The regenerated cathode powders prepared by a mixture of CTAB and PVP fuels had a specific capacity of 156 mAh g−1 at 0.1C with a capacity retention of 94 % following 100 charge/discharge cycling at a current rate of 0.5C.

Sonochemical synthesis of ortho‐aminocarbonitrile tetrahydronaphthalenes using mesoporous yolk–shell nanocomposites as a recyclable heterogeneous catalyst and evaluation of their in vitro antimicrobial activities

A mobile Ca/Mg core was formed inside the silica shell of mesoporous yolk–shell nanocomposites (CaO‐MgO@SiO2). This new structure of hollow mesoporous silica spheres has been successfully synthesized inside the inner cavity. The used carbon spheres as a rigid template in the multi‐step synthetic process are covered with tetraethyl orthosilicate (TEOS) and a mixture of cetyltrimethylammonium bromide (CTAB). Then, the tetrahydronaphthalenes were synergistically synthesized using CaO‐MgO@SiO2 nanocomposites as a nanocatalyst under ultrasound irradiation. By this technique, the required items could be produced with a high to excellent efficiency between 90% and 98% and the reaction times of 5–15 min. As an effective and reusable catalyst in multicomponent processes, the CaO‐MgO@SiO2 catalyst exhibits high reactivity. The FT‐IR, 1H NMR, and melting point methods were used to identify all of the products. Moreover, FT‐IR, XRD, FE‐SEM, EDS, Mapping, and HR‐TEM techniques are used to characterize the prepared catalysts. Also, in vitro antibacterial activity of some synthetic compounds was evaluated.

Photocatalytic properties of BiFeO3 powders synthesized by the mixture of CTAB and Glycine

Highly pure BiFeO3 (BFO) powders were prepared by the solution combustion synthesis method using cetyltrimethylammonium bromide (CTAB) and glycine as fuels at various fuel-to-oxidant (φ) ratios. Microstructural characteristics, morphology, optical properties, and thermal analysis were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), and differential thermal/thermogravimetry (DTA/TGA), respectively. The combusted powders prepared at different fuel content contained a small amount of impurity phases such as Bi24Fe2O39 and Bi2Fe4O9. During the calcination of BFO powders at 600 °C for 1 h, a nearly pure BFO phase was produced. Combusted powders photodegraded about 80% of methylene blue dye at φ = 2 through 90 min of visible light irradiation.

A novel cetyltrimethylammonium bromide-based deep eutectic solvent pretreatment of rice husk to efficiently enhance its enzymatic hydrolysis

Deep eutectic solvent (DES) has caught widely attention of researchers in biomass pretreatment. As a highly efficient surfactant, cetyltrimethylammonium bromide (CTAB) was expected to be used for synthesizing new DESs with additional functions in pretreatment. In this work, an efficient pretreatment method using a mixture of CTAB and lactic acid (LA) as a novel functional DES was established to improve enzymatic digestion efficiency of rice husk (RH). The results showed that DES CTAB:LA effectively removed lignin (51.5%) and xylan (79.9%) and the enzymatic hydrolysis activity of CTAB:LA-treated RH was 5 times that of RH. Then, a series of characterization demonstrated that a substantial accessibility increased, a hydrophobicity and lignin surface area decreased, and great surface morphology alternation were observed on the treated RH, which explained the increase in enzymatic hydrolysis efficiency. Overall, the discovery of more functional DESs might be motivated and biorefinery pretreatment processes might be greatly promoted.

Gold nanorods derivatized with CTAB and hydroquinone or ascorbic acid: spectroscopic investigation of anisotropic nanoparticles of different shapes and sizes.

Gold nanorods stabilized by binary ligand mixtures of cetyltrimethylammonium bromide (CTAB, primary ligand) and ascorbic acid or hydroquinone were investigated by complementary synchrotron radiation-induced spectroscopies and microscopies, with the aim to find evidence of the influence of the secondary ligand molecular and chemical structure on the nanorod shapes and size ratios. Indeed, as it is well known that the CTAB interaction with Ag(i) ions at the NR surface plays a key role in directing the anisotropic growth of nanorods, the possibility to finely control the NR shape and dimension by opportunely selecting the secondary ligands opens new perspectives in the design and synthesis of anisotropic nanoparticles.

Physico-chemical properties of the association of cetyltrimethylammonium bromide and bovine serum albumin mixture in aqueous-organic mixed solvents

Herein, we have investigated the association behavior of bovine serum albumin (BSA) and cetyltrimethylammonium bromide (CTAB) using the conductivity method in H2O and H2O + organic mixed solvents at different temperatures. The association phenomenon was detected from the deviation of the conductivity changes with enhancing the surfactant concentration and changes of numerous physico-chemical properties, such as CMC, α, β and thermodynamic variables (∆G0m, ∆H0m and ∆S0m). The values of CMC for the CTAB + BSA system in 10 % (v/v) solvents follow the trend: CMCwater < CMCwater+DMSO < CMCwater+AN < CMCwater+DX < CMCwater+DMF. The interaction of BSA with CTAB is notably influenced due to a change of temperature and extent of hydration of BSA and surfactant. The obtained values of –∆G0m manifest that the association of BSA and CTAB mixture is a spontaneous process, while the values of –∆G0m in presence of 10 % (v/v) aq. organic solvents come out in the given sequence: -∆Gmo (H2O + DMSO) > ∆Gmo (H2O + DMF) > -∆Gmo (H2O + DX) > -∆Gmo (H2O + AN). The H-bonding, ion-dipole, along with the hydrophobic interactions, are believed to be the binding interactions between BSA and CTAB in the study media.

Impact of ceftriaxone sodium on tetradecyltrimethylammonium bromide & cetyltrimethylammonium bromide mixture: Conductivity and theoretical investigation

The formation of mixed micelle of tetradecyltrimethylammonium bromide (TTAB) & cetyltrimethylammonium bromide (CTAB) mixture has been carried out in appearance of ceftriaxone sodium trihydrate (CTS) drug having different concentrations over a temperature range of 298.15 to 323.15 K, keeping a break of 5 K. The CMC of pure and mixture of surfactants were observed to be reliant on the concentration of drug. The CMC values of TTAB + CTAB mixture lie in between that of pure TTAB & CTAB. The larger deviation of CMC of TTAB & CTAB mixture from the corresponding ideal CMC (CMCid) at higher mole fraction (α1) of CTAB signify stronger interaction amid TTAB and CTAB at higher bulk α1 of CTAB. The negative excess free energy (ΔGexRub) values reveal the stable form of micelle and the stability was attained to be enhanced by the rise of α1 of CTAB. The interaction parameter (β) also reveals the attractive interaction amongst the studied species of surfactants. The micellar mole fraction (X1Rub), as well as its ideal (X1id) values, experience an augmentation by the rise of α1, which reveal that the contribution of CTAB increase with the raise of α1. The Gibbs free energy of micellization (ΔGm0) reveals a spontaneous association of both pure and mixed systems. The enthalpy (ΔHm0) and entropy (ΔSm0) of micellization reveal that the micellization is exothermic in nature, while the recommended forces are hydrophobic interaction, along with weak electrostatic interactions. The values of intrinsic enthalpy also reveal the micelle’s stability, thereby, formed. Degree of dissociation (g), compensation temperature, etc., were also reported.

Assembly nature and physicochemical variables of a mixture of cetyltrimethylammonium bromide + tetradecyltrimethylammonium bromide in aq. levofloxacin hemihydrate drug medium: A conductivity and theoretical approach

This study describes the development of mixed micelles between two cationic surfactants of different chain lengths, hexadecyltrimethylammonium bromide (CTAB) and tetradecyltrimethylammonium bromide (TTAB), in an aqueous solution of levofloxacin hemihydrate (LFH). The LFH is, an antibiotic drug, used to treat many bacterial infections. The conductivity method was used in this investigation at varying temperatures and concentrations of CTAB. From the conductivity versus [surfactant] plots, the critical micelle concentration (CMC) and degree of ionization (g) were determined. The differences between the experimental CMC and its ideal value (CMCid) revealed the presence of interactions amid two employed amphiphiles in creating the mixed micelles. The CMC of the TTAB + CTAB mixed system decreased as the mole fraction (α1) of CTAB was increased at a specific temperature. The values of X1Rub and X1id were larger than the corresponding stoichiometric mole fraction of CTAB (α1), which indicated that CTAB substituted the TTAB molecules from the mixed micelles, and the contribution of CTAB increased in the mixed micelles with increase of α1. The activity coefficients (f1Rub and f2Rub) also showed the contribution of CTAB in the mixed micellization. Thermodynamic variables including excess free energy (ΔGexRub) were computed. The enthalpy (ΔHm0) and entropy (ΔSm0) of the association process indicated the presence of electrostatic (ion–dipole, ion–ion) interactions as well as hydrophobic interactions between the constituents of the study system.

Assembly behaviour and thermodynamics of the mixture of cetyltrimethylammonium bromide and bovine serum albumin in aqueous and aqua-ethylene glycol mixed solvents media at several temperatures

The aggregation of the mixture of cetyltrimethylammonium bromide (CTAB) and bovine serum albumin (BSA) in aqueous and aq. ethylene glycol (EG) media has been carried out conductometrically at numerous temperatures. Conductivity values of CTAB have been changed with the concentration of CTAB and the values also experience a change with the presence of BSA, change of BSA concentration, variation of EG contents as well as the experimental temperatures. The critical micelle concentration (CMC) and the extent of micelle dissociation (α) were evaluated graphically plotting the specific conductivity against the CTAB concentration. The CTAB aggregation happens lately in the appearance of BSA. Also, the CMC values of CTAB + BSA experience an upsurge with the rise of BSA contents. The CMC values of the mixture of CTAB and BSA have been obtained to be higher in extents in aq. EG solution in contrast to water medium. In all of the circumstances inspected, the micellisation of the CTAB + BSA mixture is spontaneous (negative ΔG 0 m values). Depending on the ΔH0 m and ΔS0 m values for the CTAB + BSA mixture, the recommended forces between CTAB and BSA are electrostatic interaction (hydrogen bonding and ion-dipole interactions) and hydrophobic interactions.

Bottom-up self-assembly of nanofibers in the surfactant mixture of CTAB and Pluronics

Bottom-up self-assembly of nanofibers in a chemical method is presented using the surfactant mixture of cetyltrimethylammonium bromide (CTAB) and Pluronics as the anisotropic micellar templates. Fully fluorinated perfluorooctanoic acids with highly hydrophobic C–F chains are imported for constructing exceptionally long nanofibers. Ag(I) provides robustness of the materials by the complexation with ethylene oxides in Pluronic copolymers. Fluorocarbons reside in the PPO (polypropylene oxide) blocks in Pluronic polymers and accordingly in reverse Pluronics, they are placed in the surrounding regions of nanofibers. During the segregation of water from hydrophobic cores, self-assembly is assumed to be driven by hydrophobic interactions among alkyl chains of CTAB, fluoroalkyl chains of perfluorooctanoic acids, and dehydrated methyl groups of PPO blocks in Pluronics. Nanofibers with relatively high aspect ratios were obtained when Pluronic copolymers with low number average molecular weights (Mn), such as L-31 (Mn ∼ 1100) and L-64 (Mn ∼ 2900), were used. Heterogeneous catalytic activities were monitored in the reduction reactions of 4-nitrophenol, and the nanorods prepared from Pluronic 31R1 show the best catalytic performances with a rate constant of 0.002 35 s−1. The roles of fluorine or C–F groups in perfluorooctanoic acids are believed to be the disruption of hydrogen bonding between water and polyethylene oxide groups, and the phase separation of nanofibers from the aqueous environment by the dehydration of hydrophobic cores.

Degradation of the residual textile mixture cetyltrimethylammonium bromide/remazol yellow gold RNL-150%/reactive blue BF-5G: evaluation photo-peroxidation and photo-Fenton processes in LED and UV-C photoreactors.

This article presents a study on the degradation of a residual textile mixture composed of cationic surfactant cetyltrimethylammonium bromide (CTAB) and the remazol yellow gold RNL-150% and reactive blue BF-5G textile dyes. This was carried out by employing the photo-peroxidation and photo-Fenton processes in LED and UV-C photoreactors. The photo-Fenton process was the most efficient as regards the degradation of the CTAB and dye mixture, for both types of radiation. In the kinetic study, degradations of 99% were obtained in 180 min for the chromophore groups using both types of radiation. The degradation of the CTAB and aromatic groups was, meanwhile, an average of 25% when employing LED radiation. The behavior of the degradation reaction was pseudo-first-order. Toxicity tests indicated that the solutions were better able to grow seeds and bacteria after treatment with the photo-Fenton process, using both types of radiation. The photo-Fenton processes carried out by employing LED and UV-C photoreactors were able to degrade the CTAB and dye mixture, thus highlighting the efficiency of LED radiation when its power (three times smaller) is compared to that of UV-C radiation. This process, therefore, represents an alternative for use in textile wastewater treatment systems.

Influences of alcohol/polyols on interaction of moxifloxacin hydrochloride through cetyltrimethylammonium bromide at numerous temperatures and compositions

A study on the interaction of a fourth-generation antibiotic drug, moxifloxacin hydrochloride (MFH), with a cationic surfactant, such as cetyltrimethylammonium bromide (CTAB) in the aqueous solution of alcohol (1-propanol (1-PrOH)) and polyols (galactose/maltose), has been carried out using the conductivity measurement technique. The critical micelle concentration (cmc), micelle ionisation (α), counter ion binding (β), and thermodynamic properties (, , and ) for the self-aggregation of MFH + CTAB mixture have been estimated in 1-PrOH/polyols solutions. The presence of 1-PrOH delays the MFH + CTAB micelle formation, whereas polyols create a congenial environment for the micelle formation. In 1-PrOH, the values of α experience a reduction with the increase of 1-PrOH concentration and temperature. The values of α were found to be dependent on the concentration of other additives. In all of the cases thoroughly studied, the values of were found negative, which experience an enhancement in polyols solutions and decreased in 1-PrOH solution. On the basis of and values, the suggested interaction forces between MFH and surfactant are hydrophobic, ion-dipole, and electrostatic in nature. The values of reveal that the micelle is more stable in polyols media than that of the 1-PrOH medium.

Adsorption Properties of Hydrocarbon and Fluorocarbon Surfactants Ternary Mixture at the Water-Air Interface.

Measurements were made of the surface tension of the aqueous solutions of p-(1,1,3,3-tetramethylbutyl) phenoxypoly(ethylene glycols) having 10 oxyethylene groups in the molecule (Triton X-100, TX100) and cetyltrimethylammonium bromide (CTAB) with Zonyl FSN-100 (FC6EO14, FC1) as well as with Zonyl FSO-100 (FC5EO10, FC2) ternary mixtures. The obtained results were compared to those provided by the Fainerman and Miller equation and to the values of the solution surface tension calculated, based on the contribution of a particular surfactant in the mixture to the reduction of water surface tension. The changes of the aqueous solution ternary surfactants mixture surface tension at the constant concentration of TX100 and CTAB mixture at which the water surface tension was reduced to 60 and 50 mN/m as a function of fluorocarbon surfactant concentration, were considered with regard to the composition of the mixed monolayer at the water-air interface. Next, this composition was applied for the calculation of the concentration of the particular surfactants in the monolayer using the Frumkin equation. On the other hand, the Gibbs surface excess concentration was determined only for the fluorocarbon surfactants. The tendency of the particular surfactants to adsorb at the water-air interface was discussed, based on the Gibbs standard free energy of adsorption which was determined using different methods. This energy was also deduced, based on the surfactant tail surface tension and tail-water interface tension.

Solution combustion synthesis of hierarchical porous LiFePO4 powders as cathode materials for lithium-ion batteries

Hierarchical porous LiFePO4 powders were prepared by solution combustion method using a mixture of cetyltrimethylammonium bromide (CTAB) and glycine as fuel. The effects of fuel contents on structural, microstructural, and electrochemical properties were studied by various characterization methods such as X-ray diffraction, infrared spectroscopy, scanning electron microscopy, N2 adsorption–desorption isotherms, and galvanostatic charge/discharge. Single phase LiFePO4 powders were crystallized by calcination at 700 °C. Phase evolution was depended on the nature and amount of intermediate phases. The hierarchical porous microstructure was obtained at an appropriate amount of mixed fuels. LiFePO4 powders showed the high specific discharge capacity of 110 mAh g−1 and high capacity retention of 98% at 1C which were attributed to their high crystallinity and high specific surface areas. The porous microstructure and small particle size were benefitted for the electrode kinetics, as indicated by electrochemical impedance spectroscopy.

Several Shapes of Single Crystalline Gold Nanomaterials Prepared in the Surfactant Mixture of CTAB and Pluronics.

Twin structures in gold nanomaterials are destined because they reduce the severe strains in the misfit region of nanostructures. Defect-free single crystalline plasmonic nanomaterials gain interests these days as the integration of plasmonic materials or plasmons into electronic devices and circuits becomes more common. In this study, without subtle experimental adjustments, such as pH or halide additives, several shapes of single crystalline gold nanoparticles (NPs) are prepared in the surfactant mixture of cetyltrimethylammonium bromide (CTAB) and Pluronic triblock copolymers. The synthesized NPs are primarily composed of {100} planes with small numbers of particles possessing a [110] zone axis. Pluronic copolymers with low number average molecular weights (Mn), such as L-31 (Mn ≈ 1100) and L-64 (Mn ≈ 2900), prefer anisotropic nanorods with the aspect ratios of 4.3 and 3.0, respectively, while Pluronics with high Mn values, such as F-68 (Mn ≈ 8400) and F-108 (Mn ≈ 14 600), favor more concentric and isotropic cube-like NPs. Extended micelles are believed to form in Pluronics with low Mn values in which hydrophobic cores are merged with the increase of temperature, while the corona regions that are composed of long tails of PEO prevent the merge of hydrophobic cores, and the growth of the micelles is limited in Pluronic copolymers with high Mn values. The catalytic degradation reactions of methyl orange are conducted, and rather than isotropic particles, gold nanorods exhibit better catalytic performances. More hydrophilic environment and the steric alignment of rigid aromatic structures of methyl orange along the nanorods are thought to contribute to the catalytic activities. Overall, highly confined geometries of the appropriately swollen micellar templates of Pluronics and CTAB, which is not so hydrophobic as for the formation of contracted deswollen templates and for the inhibition of the growth of NPs, and which is not so hydrophilic as for the formation of coarse templates and for the formation of isotropic spheres with varying sizes, are believed as the main factor for the formation of single crystalline gold NPs.

Interaction of sodium alginate with cetyltrimethylammonium bromide in aqua-organic mixed solvents: influence of temperatures and compositions

Herein, the interaction of sodium alginate (SA) with cetyltrimethylammonium bromide (CTAB) has been studied in aqueous solution as well as in aqua-organic mixed solvents at varying temperatures using conductivity measurements. Ethylene glycol (EG), dimethyl formamide (DMF), 1,4-dioxane (DO), and acetonitrile (AN) were used as organic solvents. The CMC values for SA + CTAB system in 10% (v/v) mixed solvents follow the order: CMCwater + DO > CMCwater + DMF > CMCwater + AN > CMC water + EG > CMCwater. The CMC values for the SA + CTAB system in aqueous medium indicate that SA lowers the CMC of pure CTAB. The higher CMC values in all the solvent mixtures may be due to the decrease of the dielectric constant and cohesive energy density of water. The interaction of SA with CTAB is affected significantly by the change in temperature which is attributed to changes in hydration of SA and CTAB. The negative values of free energy of micellization () for the SA + CTAB system imply the spontaneous aggregation phenomenon and the negative values in H2O and 10% (v/v) mixed solvents follow the trend: (H2O) > (water + EG) > (water + DMF) > (water + DO) > (water + AN). The values of free energy changes of transfer () were also evaluated for the shift of SA + CTAB mixture from water to aqua-organic mixed solvents and discussed the results in detail. The binding interactions of SA with CTAB are proposed to be hydrogen bonding, ion-dipole, and hydrophobic interactions. The enthalpy-entropy compensation of SA + CTAB systems was assessed and illustrated in detail.

Light-Triggered Rheological Changes in a System of Cationic Wormlike Micelles Formulated with a Photoacid Generator.

“Smart” fluids displaying large changes in their rheological properties in response to external stimuli have been of great interest in recent years. For example, “smart” wormlike micelles (WLMs) that respond to pH can be readily formulated by combining a cationic surfactant such as cetyltrimethylammonium bromide (CTAB) with an aromatic compound such as 1,2-dihydroxybenzene (DHB). Here, we show that a pH-responsive aqueous formulation as mentioned above can be simultaneously made responsive to ultraviolet (UV) light by incorporating a photoacid generator (PAG) into the system. A commercially available PAG, diphenyliodonium-2-carboxylate, is used here. Upon exposure to UV light, this PAG irreversibly photolyzes into iodobenzene (IB) and benzoic acid (BA), with the formation of BA, leading to a drop in pH. WLMs formed by mixtures of CTAB, DHB, and the PAG are systematically characterized before and after UV irradiation. As the PAG photolyzes, an increase in the viscosity of WLMs occurs by a factor of 1000. We show that the ratio of the zero-shear viscosity η0 (after UV/before UV) depends on the initial pH of the sample. The UV-induced increase in η0 can be attributed to the growth of WLMs in solution, which in turn is influenced by both the ionization state of DHB and the presence of IB and BA.

Performance of graphene dispersion by using mixed surfactants

In this work the ability of pure surfactant Sodium Dodecyl Sulfate (SDS), Cetyltrimethyl Ammonium Bromide (CTAB) and their mixed surfactants for graphene dispersion in aqueous solution was investigated. The uniform and stable dispersion solution was obtained for graphene with the mixtures of SDS and CTAB at lower concentration as compared to the pure one. The SDS-based surfactants exhibited better dispersion as compared to CTAB-based surfactants due to smaller-sized graphene as was investigated via Zeta potential measurements. Zeta potential was utilized to characterize the colloidal stability of surface charges within the mixtures. The mixed surfactants utilized in the present study showed a better ability to disperse graphene and its derivatives and hence are well suited for practical applications.

Effect of Surfactants on Shape of Gold Nanoparticles

In a binary mixture of cetyltrimethylammonium bromide (CTAB) and benzyldimethyltetradecyl ammonium chloride (BDTAC), gold nanorods with a maximum absorption of longitudinal plasmon resonance up to 1600 nm have been obtained. It has been shown that the shape of the growing nanoparticles is determined by the CTAB/BDTAC molar ratio. The optimal conditions have been found for the synthesis of homogeneous nanorods with an aspect ratio of 1 : 7 in a high yield, providing their rapid formation with subsequent slow and uniform growth. The use of a CTAB/BDTAC mixture allows preventing the change in particle shape due to recrystallization during their long-term storage, as is observed in the presence of CTAB.