Dodecyltrimethylammonium Bromide Research Articles

On the mechanism of Ca(OH)2 structure modulation by surfactants: Experimental and calculative studies

Surfactants are widely used for structure modulation of calcium-based materials. However, the modification mechanisms underlying the CaO digestion improved by surfactants for Ca(OH)2 production remain unclear. This study employed experiment methods, Density Functional Theory (DFT), and Molecular Dynamics methods (MD) to reveal the mechanism of surfactant modulation at a molecular level. The adsorption energy of Primary Alcohol Ethoxylate (AEO), Sodium Dodecyl Sulfate (SDS), H2O, and Dodecyl Trimethyl Ammonium Bromide (DTAB) on CaO(001) surface were −52.62, −51.98, –23.79, and 3.96 kcal/mol, respectively. The strong chemisorption of AEO and SDS on the surface of CaO improved its structure stability. AEO and SDS weakened the diffusion of H2O to CaO surface, thus causing the reaction between CaO and H2O to be suppressed. After being modulated by SDS and AEO, better crystallinity of Ca(OH)2 and finer crystalline grains were observed with the formation of developed pore structure. AEO has a longer molecular chain, giving better modification performance. On the contrary, DTAB accelerated the diffusion of H2O to CaO surface, leading to more energy released and causing the fast growth of Ca(OH)2 crystals, as evidenced by the much larger particle size compared to that of AEO and SDS. This process led to the creation of a larger pore structure. Desulfurization was used as a performance indicator to evaluate the surfactants modulation efficacy. The sulfur capacity of Ca(OH)2 regulated by 1 % AEO was 100.05 mg/g, being the highest among the used surfactants. For comparison, the sulfur capacity without additives was 49.64 mg/g. This study shows that nonionic surfactants are an ideal choice for regulating the structure of Ca(OH)2, as they can effectively inhibit crystal growth.

Switchability and synergistic effect of a CO2-responsive surfactant with co-surfactants at an O/W interface: A molecular insight

CO2-responsive surfactants are a promising technology with potential applications in various fields. Therefore, the design of their formulations must be carefully considered to ensure their effectiveness in each specific application. Herein, we employed molecular dynamics simulations to investigate an oil/water (O/W) interface stabilized by a surfactant mixture containing a CO2-responsive cationic primary surfactant and another co-surfactant. It has been discovered that formulating the CO2-responsive cationic surfactant with a typical anionic surfactant (sodium dodecyl sulfate, SDS) can lead to a distinct CO2-responsive mechanism of the surfactant mixture. To compare, the CO2-responsive mechanism remains unchanged if the CO2-responsive cationic surfactant is formulated with a typical cationic surfactant (dodecyl trimethylammonium bromide, DTAB). A nonionic co-surfactant can enhance the interface activity of the surfactant mixture but the synergistic effect is not strong enough to lead to a different CO2-responsive mechanism. The distinct phase behavior between two surfactant mixtures suggests that the CO2-responsive mechanism is dominated by the type of surfactants formulated with the CO2-switchable surfactant.

Surface-active ionic liquids as drug carriers: A physico-chemical study

This work evaluates the potential of two surface active ionic liquids (SAILs) 1-dodecyl-3-methylimidazolium bromide and 1-tetradecyl-3-methylimidazolium bromide as drug carrier for ciprofloxacin (CPF) and compares them with their conventional counterparts dodecyltrimethylammonium bromide and tetradecyltrimethylammonium bromide using spectroscopic and electrochemical techniques. Different physico-chemical parameters including critical micelle concentration (CMC), binding constants, partition coefficients and their corresponding free energy changes, thermodynamic parameters of micellization and redox behavior of micelle-drug systems were investigated. Both the SAILs demonstrated higher solubilization powers and binding constants owing to the less polar nature of imidazolium ring. Lower CMCs indicated relatively stronger hydrophobic forces existing in all SAILs-CPF systems tested. The cyclic voltammetry displayed shifting of oxidation peaks towards higher positive potential in the micellar region indicating the protection of CPF against oxidation. This work demonstrates the benefits of using SAILs as drug carriers due to their lower CMCs, improved binding and partition coefficients, and favorable electrochemical results.

Enhancing the shale inhibition performance of low-melting mixture solvents utilizing DTAB in water-based drilling fluids

Wellbore instability issue is a common occurrence in the development of clean energy sources such as shale gas. Low-melting mixture solvents (LoMMSs), as a novel and environmentally friendly liquids material, are anticipated to be utilized to address this issue. In this work, a novel shale inhibitor (LoMMSs-2) was formulated through introducing a cationic surfactant with a long hydrophobic chain, dodecyl trimethyl ammonium bromide (DTAB), into a commonly used choline chloride/glycerol LoMMSs. Inhibition assessment results indicated that the swelling height of bentonite in LoMMSs-2 solutions decreased by 53.46 %, and shale recovery rate reached as high as 89.51 %, demonstrating superior hydration inhibition compared to commercial inhibitors. The mechanism for inhibiting hydration in LoMMSs-2 was explored through tests involving zeta potential, particle size, interlayer spacing, shale wettability, and surface tension, etc. The findings revealed that choline cations and quaternary ammonium cations in LoMMSs-2 could tightly adsorb to the clay surface. The exposed long alkyl chains made the rock more hydrophobic, increasing the water contact angle from 22.49° to 65.26°. Subsequently, more interlayers water in the clay was expelled, leading to a significant reduction in adsorbed water. Additionally, the lower surface tension and stronger hydrophobicity corresponded to a smaller capillary force, further minimizing water infiltration into shale. Therefore, introducing hydrophobic groups into LoMMSs was a promising approach for developing efficient shale inhibitors to address wellbore instability issue in shale gas drilling.

Surface methyl/methylene regulates WO3 directional activation of molecular oxygen into singlet oxygen for the removal of organic pollutants in water

The efficient removal of organic pollutants using singlet oxygen (1O2) represents a pivotal advancement in environmental purification. Despite its potential, the controlled generation of 1O2 remains a challenging endeavor. In this study, we present a novel approach whereby methyl/methylene are utilized to modulate the production of 1O2 by tungsten trioxide (WO3), thereby enhancing the photocatalytic degradation of persistent pollutants through deep oxidation. Employing a dodecyltrimethylammonium bromide (DTAB)-assisted hydrothermal synthesis, we successfully fabricated WO3 capable of generating 1O2. This modified WO3 demonstrates superior performance in the photocatalytic degradation of chloroquine phosphate by facilitating the rapid separation of photo-generated electron-hole pairs, thereby accelerating the degradation process. Furthermore, WO3 augmented with 1O2 exhibits enhanced efficacy in decomposing other challenging organic contaminants, compared to its untreated counterpart. Our findings not only contribute to the advancement of photocatalytic design principles centered on 1O2 but also underscore the critical role of controlled 1O2 production in the effective eradication of pollutants.

Comparison of dodecyl trimethyl ammonium bromide (DTAB) and cetylpyridinium chloride (CPC) as corrosion inhibitors for mild steel in sulphuric acid solution

Two essential cationic surfactants, dodecyl trimethyl ammonium bromide (DTAB) and cetyl pyridinium chloride (CPC) with differences in the alkyl chain, were investigated as corrosion inhibitors on mild steel (MS) in 0.5 M H2SO4 with weight loss (WL) and the potentiodynamic polarization (PDP) method. Three different temperatures were used to maintain the reported sample solutions (298.15, 308.15, and 318.15 K) for concentrations ranging below, above, and at the optimum critical micelle concentration (CMC) of the cationic surfactants. Results show that 0.5 M DTAB having ammonium group gave higher inhibition efficiency than 0.5 M CPC having pyridinium group by PDP method. The inhibition efficiencies were determined as 98.6% for 0.5 M DTAB and 89.38% for 0.5 M CPC after 24 h immersion at 298.15 K. The extreme inhibition efficiency depends on the chain length and decreases with an increase in temperature as well as increases with the addition of concentration of cationic surfactants. Around CMC, both surfactants CPC and DTAB showed the highest inhibition efficiency which follows the isotherm of Langmuir adsorption and illustrates a mixed type of corrosion inhibitors with the predominance of cathodic reactions. Additionally, the proposed mechanisms of inhibitors showing both physical and chemical adsorption confirmed by the free energy of adsorption (-ΔGads0) for DTAB were >28–34.5 kJ/mol and for CPC were >31.07–42.91 kJ/mol.

Dynamic Interfacial Properties and Foamability of DoTAB/SiO2 Mixtures

The interaction between nanoparticles and cationic surfactants is an exciting and emerging field in interfacial science. This area of research holds significant promise, linking fundamental principles to practical applications in a variety of industries, including chemical processes, biomedical applications and the petroleum industry. This study explores the interaction between dodecyltrimethylammonium bromide (DoTAB) and silica (SiO2) nanoparticles, investigating their influence on dynamic interfacial properties and foam characteristics. Through equilibrium and dynamic surface tension measurements, along with examining the dilational visco-elasticity behavior, this research reveals the complex surface behavior of DoTAB/SiO2 mixtures compared to individual surfactant solutions. The foamability and stability experiments indicate that the addition of SiO2 significantly improves the foam stability. Notably, stable foams are achieved at low SiO2 concentrations, suggesting a cost-effective approach to enhancing the foam stability. This study identifies the optimal stability conditions for 12 mM DoTAB solutions, emphasizing the crucial role of the critical aggregation concentration region. These findings offer valuable insights for designing surfactant-nanoparticle formulations to enhance foam performance in various industrial applications.

Investigation of synergistic mechanism of magnesium ions and cationic surfactant in low-rank coal flotation

The effect of magnesium ions on the adsorption of DTAB (Dodecyltrimethylammonium Bromide) surfactants by low-rank coal using adsorption experiments and microscopic mechanism analysis. In addition, the flotation recovery of coal was summarized for application by micro flotation test. The results of adsorption experiments showed that 0.1 mM magnesium ions concentration is optimal, with 12.55 mg/g adsorption capacity. Besides, correlation analysis reveals that the adsorption capacity is positively correlated with temperature, surfactant concentration, reaction time and the magnesium ions density. Adsorption thermodynamics and kinetics experiments indicate that magnesium ions promote adsorption by increasing the adsorption active sites of coal and accelerating the adsorption rate of DTAB on coal. Furthermore, the results of contact angle, zeta potential, model calculations and FTIR (Fourier transform infrared spectroscopy) analyses reveal that magnesium ions and its hydrolysates can adsorb on the coal as a bridge and destroy the stable hydrogen bond on the coal to activate the adsorption, which enhance the negatively charged coal to electrostatically adsorb positively charged DTAB. Moreover, the recovery rate of low-rank coal flotation using DTAB combined with magnesium ions was tested by a micro flotation apparatus, which provides a guidance for the flotation application by saline surfactant solution on coal.

Long-Term Thermal Stability of Ionic Surfactants for Improving Oil Production at High-Salinity High-Temperature Conditions.

Surfactants with stable chemical structures and robust ability are required to lower interfacial tension and stabilize emulsions for successful chemical injection applications. This work selected six surfactants, dodecyl carboxylic sodium (LAS), dodecyl sulfonate dodecyl sodium (SLS), dodecyl sulfate sodium (SDS), dodecyltrimethylammonium bromide (DTAB), 3-(N,N-dimethylmyristylammonio) propanesulfonate (SB3-14) and a sulfobetaine formulation (PCT-10), and systematically investigated the ionic-type effects on thermal stability at 95 °C for 150 days in high-salinity water (total dissolved solids (TDS) = 57,600 ppm). With characterizations of aged samples performed through a spinning drop tensiometer, high-performance liquid chromatography, and infrared spectroscopy, it can be seen that the long-term stability sequence of ionic surfactants in solutions is sulfobetaine ≈ quaternary ammonium > sulfonate > sulfate > carboxylate. The carboxylate possibly precipitates out from the solution in the acid form, and the sulfonate and sulfate decompositions are due to the hydrolysis of the anionic head, forming alcohol and NaHSO3/NaHSO4. Obvious decomposition of sulfobetaine and quaternary ammonium was not observed, but these molecules might suffer the elimination of the ionic head, forming the corresponding alkene and amine. The results also show that the dissolved oxygen in the solution preparation significantly sped up the degradation of sulfonates. At last, the emulsion stability tests of crude oil in surfactant solutions showed that sulfobetaine surfactants retained the highest emulsifying ability after thermal aging and thus are promising candidates for long-term chemical injection in high-temperature high-salinity reservoirs.

Kinetic and adsorption isotherm studies of Malachite Green dye onto surfactant-tailored alginate hydrogel beads: An influence of surfactant hydrophobicity

This study details the synthesis and characterization of surfactant-modified sodium alginate hydrogel beads crosslinked with Ba2+ ions through ionotropic gelation. Cationic surfactants such as, dodecyltrimethylammonium bromide (DTAB), didodecyldimethylammonium bromide (DDAB), and butanediyl-α,ω-bis-(dimethyldodecylammonium bromide) (GEM), were employed in the modification process. The surfactant-modified ALG-DTAB, ALG-DDAB, and ALG-GEM beads were investigated for the removal of cationic dye Malachite Green (MG) to elucidate the impact of hydrophobicity of amphiphiles on the adsorption process. The characterizations were carried out using Rheometry, Field Emission Scanning Electron Microscopy (FESEM), Infrared Spectroscopy (IR), and Energy Dispersive X-ray Spectroscopy (EDX). Under optimized conditions, ALG-GEM and ALG-DDAB demonstrated highest maximum adsorption capacity (Qmax > 700 mgg−1). The adsorption data fitted well to pseudo-second order kinetic and Langmuir adsorption models, suggesting the involvement of chemisorption phenomena with notable contributions from pore diffusion. The effects of pH, initial dye concentration, adsorbent dose, temperature, and competing ions on the removal of MG were investigated. Interestingly, ALG-GEM beads exhibited an increase in adsorption capacity with rising pH and a subsequent decrease with increasing temperature, showcasing optimal adsorption at pH 7.0 and 25 °C. The study proposes that ALG beads modified with cationic surfactants with higher hydrophobicity could offer a promising avenue in wastewater treatment processes.

Binary Mixed Micelles of Hexadecyltrimethylammonium Bromide–Sodium Deoxycholate and Dodecyltrimethylammonium Bromide–Sodium Deoxycholate: Thermodynamic Stabilization and Mixed Micelle Solubilization Capacity of Daidzein (Isoflavonoid)

Binary Mixed Micelles of Hexadecyltrimethylammonium Bromide–Sodium Deoxycholate and Dodecyltrimethylammonium Bromide–Sodium Deoxycholate: Thermodynamic Stabilization and Mixed Micelle Solubilization Capacity of Daidzein (Isoflavonoid)

Observation of Electrostatically Driven Surface Adsorption in Mixed Surfactant Systems.

We employed heterodyne-detected vibrational sum-frequency generation (HD-VSFG) spectroscopy to obtain a molecular-level understanding of the interaction between the anionic surfactant sodium dodecyl ammonium sulfate (SDS) and the cationic surfactant dodecyltrimethylammonium bromide (DTAB). We observed that these surfactants show a strong cooperative effect on their adsorption to the water-air interface. Even at bulk concentrations 1000 times lower than the critical micelle concentrations of SDS and DTAB, a nearly complete surface surfactant layer is observed when both surfactants are present. This strong enhancement of the surface concentrations of DS- and DTA+ can be quantitatively explained from the favorable Coulomb interaction of the oppositely charged headgroups of DS- and DTA+ and the electrostatic interactions with their counterions. The HD-VSFG results are complemented by a modified Langmuir adsorption model in which we include the free energy associated with the electrostatic interactions of the surfactant ions and their counterions.

Role of Alkyl Chain Length in Surfactant-Induced Precipitation of Reactive Brilliant Blue KN-R

To develop a cost-effective method for the effective removal of reactive brilliant blue KN-R (RBB KN-R) from wastewater, we investigated the interactions between RBB KN-R and three cationic surfactants with different alkyl chain lengths, namely dodecyltrimethylammonium bromide (DTAB), tetradecyltrimethylammonium bromide (TTAB), and cetyltrimethylammonium bromide (CTAB). Employing a conductivity analysis, surface tension analysis, ultraviolet-visible spectrophotometry, and molecular dynamics simulation, we ascertained that RBB KN-R formed a 1:1 molar ratio dye–surfactant complex with each surfactant through electrostatic attraction. Notably, an augmentation in alkyl chain length correlated with increased binding strength between RBB KN-R and the surfactant. The resulting dye–surfactant complex exhibited heightened surface activity, enabling interactions through hydrophobic forces to generate dye–surfactant aggregates when the molar ratio was below 1:1. Within these mixed aggregates, self-assembly of RBB KN-R molecules occurred, leading to the formation of dye aggregates. Due to the improved hydrophobicity with increased alkyl chain length, TTAB and CTAB could encapsulate dye aggregates within the mixed aggregates, but DTAB could not. The RBB KN-R aggregates tended to distribute on the surface of the RBB KN-R-DTAB mixed aggregates, resulting in low stability. Thus, at a DTAB concentration lower than CMC, insoluble particles readily formed and separated from surfactant aggregates at an RBB KN-R and DTAB molar ratio of 1:4. Analyzing the RBB KN-R precipitate through scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) and measuring the DTAB concentration in the supernate revealed that, at this molar ratio, all RBB KN-R precipitated from the dye–surfactant mixed solution, with only 7.5 ± 0.5% of DTAB present in the precipitate. Furthermore, the removal ratio of RBB KN-R reached nearly 100% within a pH range of 1.0 to 9.0 and standing time of 6 h. The salt type and concentration did not significantly affect the precipitation process. Therefore, this simultaneous achievement of successful RBB KN-R removal and effective separation from DTAB underscores the efficacy of the proposed approach.

Thymoquinone-Micellar Interactions: A physico-chemical investigation at molecular level

Thymoquinone (TQ) is considered the most-active component of the well-known essential oil of the black cumin/seeds (Nigella sativa L.), also known for its wide-spectrum anticancer and other pharmacological potentials since ancient times. Apart from its thermo- and photo-sensitive nature, TQ has also been reported to demonstrate strong hydrophobicity and low bioavailability. These physico-chemicals, properties hinder the development of a successful oral dosage formulation. Interaction of the pharmacologically active molecule with biological membranes is crucial step to manifest health-related effects. However, further insight into the biophysical interactions of “active” natural chemotherapeutics with cellular membranes can play a vital role in designing and developing new anti-cancer regimens. In this context pseudo-membrane models comprising ionic and non-ionic micelles offer a useful way to explore in vitro drug-membrane interactions at the molecular level. The present study focuses on the physicochemical interactions of a thymoquinone (TQ) with micelles of ionic (dodecyl trimethylammonium bromide, DTAB; and sodium dodecyl sulfate, SDS) and non-ionic (tween-80 and TX-100) surfactants at the molecular level in aqueous medium. Volumetric and acoustic parameters (apparent molar volume (ɸV), isentropic compressibility (Ks), apparent molar isentropic compressibility (ɸk), specific acoustic impedance (Z), relative association (RA), intermolecular free length (Lf)) are calculated from experimental data of density and sound velocity and interpreted in terms of solute/solvent–solute/solvent interactions using the co-sphere overlap model and the electrostriction effect. Further, UV spectroscopy and conductivity studies are used to predict the locus of TQ in the micelles, binding constant (Kb), partition coefficient (Kc), and free energy changes of TQ-micelle systems in the presence of surfactants. The results show that the binding and partitioning of TQ is more significant with TX-100 as compared with other ionic and non-ionic surfactants used.

Critical Analysis of Surfactant-Dye Interaction: A Review

The interaction between surfactants and dyes is fundamental in achieving the desired coloration and properties in various applications, shaping the functionality and effectiveness of dye-related processes across multiple industries. Further research and advancements in this field will continue contributing to innovative solutions and improved sustainability. While mixed surfactants offer these advantages, the choice between using a single surfactant or a mixture depends on the specific application, the desired properties, cost considerations, and compatibility with other formulation components. It's important to carefully evaluate the application requirements and conduct appropriate testing to determine the most effective approach. In this work, the physical-chemical characteristics and solubilization of reactive dyes in single and mixed micellar media are elaborated. Compared to the single-micellar medium, the mixed-micellar medium showed improved reactive dye trapping, which was attributed to the presence of both cationic and nonionic surfactants, namely cetyltrimethylammonium bromide (CTAB) and triton X-100. In this interactional study, two reactive dyes were used: Reactive Black 5 (RB) and Reactive Yellow 145 (RY). It is noteworthy to examine the modeling and micellization of mixed surfactant systems in an aqueous medium including dodecyl trimethylammonium bromide (DTAB) and sodium dodecyl sulfate (SDS). The anionic-rich and cationic-rich interactions between methylene blue (MB) and methyl orange (MO) in aqueous solutions were clearly shown in the diagram.

Physicochemical investigations of interaction of antitumor etoposide with ionic and nonionic micelles: a spectroscopic, conductivity and voltammetric study

This work aims to comprehend the physicochemical interaction of etoposide (trade name “VP-16”) with biological membranes using biomembrane models. Surfactants, owing to their remarkable chemical similarity with biomembranes, can be used to simulate the interactions and behavior of VP-16 in biological systems. The present study explores the physicochemical interactions of chemopreventive VP-16 with ionic dodecyltrimethylammonium bromide (DTAB), sodium dodecyl sulfate (SDS), and nonionic TX-100 & Tween-80 surfactants at the molecular level using different techniques. UV-visible spectroscopy results at 298.15 K indicate that both hydrophilic and hydrophobic interactions significantly influence the solubility of the drug in micellar systems. According to the estimated partition coefficient (Kx ) and binding constant (Kb ) obtained from the differential mode of the UV-Vis, VP-16 exhibits better binding and partitioning with nonionic surfactants compared to ionic surfactants. Thermodynamic parameters ( Δ H m o , Δ S m o , & Δ G m o ) are computed from 298.15 K to 318.15 K with a temperature interval of 5 K using conductivity data. The positive values of Δ H m o and Δ S m o and the negative values of Δ G m o indicate the disruption of water structure during the micellization process in the presence of VP-16 and the spontaneous transport of drug molecules into micelles, respectively. Voltammetric data at 298.15 K show that DTAB and TX-100 favor the oxidation of VP-16. This kind of study may be used to modify currently available drugs, design new chemotherapeutics, and formulate effective drug delivery systems to boost the drugs bioavailability.

Removal of imipramine hydrochloride with natural and recycled adsorbents from aqueous solutions: effect of surfactants on the adsorption characteristics of pharmaceutically active compounds

In this study, the adsorption properties of an amphiphilic cationic drug imipramine hydrochloride (IMP) on natural and recycled adsorbents, such as bentonite (BENT), Fuller’s earth (FE), and the eggshell (ES) in the aqueous medium has been aimed to report by means of absorption spectrophotometry. The adsorption of IMP has also been studied in the presence of cationic (dodecyl trimethylammonium bromide; DTAB) and anionic (sodium dodecyl sulfate; SDS) surfactants to clearly understand and identify the adsorption characteristics of IMP in different environments. Therefore, the association of IMP with surfactants has also been conducted using both absorption spectrophotometry and surface tension measurements to gain more information on the adsorption characteristics of IMP on BENT, FE, and ES. Micellar binding constants of IMP to SDS and DTAB micelles were calculated using the Benesi–Hildebrand Equation to ensure a more particular comparison of the effect of surfactants on the adsorption features of IMP. Additionally, the interfacial parameters Gibbs surface excess (Γ max) and the minimum area occupied by IMP (A min) were estimated in the case of DTAB and SDS. Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherm equations were applied to the adsorption of IMP on natural adsorbents. Depending on their structure, the presence of surfactants in the environment diminished or completely inhibited the adsorption of IMP on all-natural adsorbents studied with the exception of IMP adsorption on FE in the presence of SDS monomers in the medium where the adsorption quantity increased significantly.

A PVC‐Membrane Cationic Surfactant Sensitive Potentiometric Sensor: Potentiometric Determination of Dodecyltrimethyl Ammonium Ion

AbstractA potentiometric poly (vinyl chloride) (PVC) membrane cationic surfactant‐selective sensor based on a dodecyltrimethylammonium‐phosphotungstate ion pair as an electroactive material was suggested for the determination of dodecyltrimethylammonium bromide. Membrane optimization studies revealed that the PVC membrane in the composition of 0.5 % dodecyltrimethylammonium‐phosphotungstate ion pair, 69.5 % o‐nitrophenyloctylether and 30.0 % PVC displayed the best potentiometric performance properties. The sensor exhibited a linear response to dodecyltrimethylammonium ions in the concentration range of 1.0×10−6–1.0×10−2 mol L−1 with a detection limit and sensitivity of 5.0×10−7 mol L−1 and 56.6 mV/decade, respectively. The response of the sensor to dodecyltrimethylammonium cation was quite stable, sensitive, selective and rapid (<10 s). The life span of the sensor was found to be about 3 months. The analytical applications of the sensor were successfully carried out with the developed sensor as an indicator electrode for the determination of the end‐point of dodecyltrimethylammonium ions titration and dodecyltrimethylammonium contents of synthetic water samples.

Synthesis of Newly Discovered Carbon Nanoframes: A Self‐Assembly Strategy Based on DTAB @ NaCl

AbstractCarbon nanomaterials have attracted much attention in the field of science and technology for their excellent properties; however, developing a simple, environmentally friendly, and versatile synthesis strategy for the preparation of carbon nanomaterials with novel structures remains a great challenge. Herein, a surfactant @ salt (dodecyltrimethylammonium bromide DTAB @ NaCl) self‐assembly strategy for the synthesis of carbon nanomaterials with novel structures, i.e., carbon nanoframes is reported. The synthesis differs from the traditional template method in that it is characterized by the introduction of surfactants for separation and protection, and the salt can be recycled. In addition, the carbon frame size in this system can be adjusted on demand by simply adjusting the concentration of surfactant, thus realizing that the carbon nanoframe size is adjustable in the range of 232.58–322.51 nm. Impressively, the carbon nanoframe has purple, blue, and green PL emission behavior. It is anticipated that this research will provide new insights into the development of novel carbon nanomaterials.

Production of surfactant-modified banana peel biosorbents applied to treatment and decolorization of effluents

In this study, banana peels (BP) were pretreated under different conditions and modified with surfactants cetyltrimethylammonium bromide (CTAB), dodecyl trimethylammonium bromide (DTAB), or sodium dodecyl sulfate (SDS). The biosorbents were used for the removal of the anionic Direct Blue 86 (DB86) from synthetic solutions as well as for the treatment of a textile effluent. The biosorbents were characterized by Fourier Transform Infrared Spectroscopy (FTIR), contact angle measurements, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and point of zero charge (pHPZC). The results showed that the pretreatment using natural oxidation of BP showed better adsorbent performance than other pretreatments at pH 2. Treatment with SDS did not improve the sorption efficiency of the material. The biosorbents modified with DTAB (B-DTAB) and CTAB (B-CTAB) showed good performance with a maximum dye removal of 96.2% (at pH 2) and 91.7% (at pH 6), respectively, using 1.00 g L−1 of the biosorbents, constant stirring of 150 rpm for 60 min at 25 °C, and DB86 concentration of 10.0 mg L−1. The kinetics of B-DTAB and B-CTAB showed the best fit to the pseudo-first and pseudo-second-order models, respectively. The intraparticle diffusion model suggested that adsorption on B-CTAB may be guided by pore and film diffusion. Sips isotherm was found to be the best fit with theoretical maximum adsorption capacities from non-linear fit of 25.2 and 147 mg g−1, respectively, for B-DTAB and B-CTAB (1.00 g L−1 of the biosorbents, constant stirring of 150 rpm, 25 °C, and initial pH 6). Results suggest that mainly precipitation, hydrophobic interactions, and electrostatic attraction drives the sorption process. The treatment of the textile effluent using B-CTAB resulted in a reduction of 60.6% in color and 53.2% in effluent turbidity, demonstrating the potential of modified banana peels as promising biosorbents for environmental applications.