CTAB Solution Research Articles

Mechanistic impact of Stern bilayer-based electrolysis on the enhancement of pool boiling heat transfer

Pool boiling is a heat transfer method that utilizes phase change for efficient heat transfer, and enhancing its heat transfer intensity and understanding the mechanism is of great practical significance for refrigeration and microelectronics thermal management. This study employs experimental methods to innovatively use ionic surfactant modification on heating surfaces, building on the basis of strengthening heat transfer by generating hydrogen bubbles through water electrolysis to increase nucleation sites on the heating surface. The Stern double layer formed on the heating surface is utilized to control the growth rate and quantity of hydrogen bubbles, thus achieving controllable nucleation density on the heating surface. The study examines its impact on heat transfer efficiency and the onset of nucleate boiling (ONB). Results indicate that electrolysis can increase nucleation sites at low heat fluxes, thereby enhancing heat transfer. Using a CTAB solution at a concentration of 3200 ppm with an electrolytic current of 0.08A, under the Stern potential at saturated adsorption, the heat transfer coefficient increased by up to 3.16 times. Additionally, the superheat at ONB decreased from 12.6 K to 4.4 K under boiling heat flux. Therefore, utilizing electrolysis with the addition of surfactants to enhance rapid cooling of high-temperature surfaces provides a novel engineering application approach.

Synergistic enhancement of foam stability by nanocellulose and hydrocarbon surfactants

Synergistic effects and stability mechanism of carboxylated cellulose nanofiber (CCNF) and hydrocarbon surfactants on the environmentally friendly foam are investigated in this work. Higher concentrations of CCNF decelerate the bubble coarsening and liquid drainage processes, consequently enhancing foam stability. Increasing viscosity is the primary cause of foam stability enhancement for all surfactant solutions. However, the generation of aggregates is still another reason for the enhanced stability of CTAB/CCNF foam. In addition, CCNF diminishes the foaming ability of all surfactants. Furthermore, as CCNF exceeds 0.8 wt.%, the foaming ability of all surfactants diminishes noticeably, with CTAB solution experiencing a more pronounced reduction. In SDS solutions, the foaming ability is governed by viscosity, whereas in CTAB solutions, it is influenced by adsorption kinetics and viscosity.

A biosensor method based on surfactant-mediated surface droplet evaporation for the detection of Aflatoxin B1

Aflatoxin B1 (AFB1) is a common mycotoxin that is of significant global concern due to its impact on food safety. Herein, we innovatively develop a sensing platform to detect AFB1 based on evaporation of surfactant solutions on the hydrophobic surface, resulting in dried patterns with varied sizes. The surfactant CTAB solution produces a relatively large dried pattern due to the surface wetting. However, the reduction in the dried pattern size is found when the mixture of CTAB and AFB1 aptamer is tested, because the formation of CTAB/aptamer complex. Moreover, the dried pattern size of the mixture of CTAB, aptamer, and AFB1 increases due to the specific binding of AFB1 to its aptamer. Using this innovative strategy, the AFB1 detection can be fulfilled with a detection limit of 0.77 pg/mL. As a simple, convenient, inexpensive, and label-free method, the surfactant-mediated surface droplet evaporation-based biosensor is very promising for various potential applications.

Influence of pH on spectroscopic and interfacial features of phenol in aqueous cetrimonium bromide solutions of different concentrations

Phenol is an aromatic compound with toxic effects on the environment and living organisms. Cetrimonium bromide (CTAB) is a cationic, quaternary ammonium surfactant, constituent in industrial formulations, and is employed for solubilization as well as removal of pollutants. This study explores the impact of pH on the behavior of phenol in the micellar solution of CTAB via UV–Visible spectroscopy and surface tension measurements at room temperature. Binding coefficient (Kb), free energy change of binding (ΔGb), change in molar absorptivity (Δε), partition coefficient (Kc), free energy change of partitioning (ΔGp) and number of molecules per micelle (n) were determined at different pH. Results showed that phenol exhibits no appreciable interaction with the CTAB, however phenolate ions have the tendency to bind with CTAB micelles and penetrate in the palisade layer of CTAB.Surface properties such as surface excess (τmax), minimum area per molecule (Amin), packing parameter (P), surface area per head group (as), free energy changes of micellization (ΔGm), adsorption ΔGads, and transfer (ΔGtrans), and surface pressure (Π) for CTAB, and phenol in CTAB solutions were also determined. Interfacial studies supported the role of phenol in facilitating micellization of CTAB thermodynamically and hence a fall in CMC values of CTAB except for pH 7.11. Calculated interfacial parameters established the influence of phenol over rearrangement and surface adsorption of CTAB molecular ions at air/water interface. Surface tension results also showed that unionized phenol molecules have low surface activity (62.23mN/m), but when phenol is ionized into phenolate ion surface dramatically increased (44.17 mN/m).

A smartphone-based colorimetric assay using Cu-tannic acid nanosheets (Cu-TA NShs) as a laccase-mimicking nanozyme for visual detection of quercetin in vegetables.

Theinteraction of Cu-tannic acid nanosheets (Cu-TA NShs) as nanozyme in a surfactant solution of CTAB under relatively acidic conditions is shown toexhibit a catalytic effect on quercetin (Qur). This catalytic property of Cu-TA NShs, which mimics laccase enzyme with many advantages, has been applied todeveloping a selective colorimetric sensor for the determination of trace amounts of Qur in vegetable samples. This strategy presents a desirable linear relationship between the absorbance signal intensity and the concentrations of Qur from 0.350 to 32.09 µM with a detection limit (LOD) of 0.064 µM (S/N = 3). The feasibility of the proposed portable colorimetric sensor for in situ analysis of the real samples has been validated with the high-performance liquid chromatography (HPLC) method as reference method, and two-tailed test (t test) statistical analysis certifies good agreement between the results. This enzyme-free and sensitive naked-eye sensor with the smartphone-based color map is promising to provide technical support for the rapid and visual detection of Qur in vegetables.

Self-Assembled FeIII-TAML-Based Magnetic Nanostructures for Rapid and Sustainable Destruction of Bisphenol A.

This study focused on constructing iron(III)-tetraamidomacrocyclic ligand (FeIII-TAML)-based magnetic nanostructures via a surfactant-assisted self-assembly (SAS) method to enhance the reactivity and recoverability of FeIII-TAML activators, which have been widely employed to degrade various organic contaminants. We have fabricated FeIII-TAML-based magnetic nanomaterials (FeIII-TAML/CTAB@Fe3O4, CTAB refers to cetyltrimethylammonium bromide) by adding a mixed solution of FeIII-TAML and NH3·H2O into another mixture containing CTAB, FeCl2 and FeCl3 solutions. The as-prepared FeIII-TAML/CTAB@Fe3O4 nanocomposite showed relative reactivity compared with free FeIII-TAML as indicated by decomposition of bisphenol A (BPA). Moreover, our results demonstrated that the FeIII-TAML/CTAB@Fe3O4 composite can be separated directly from reaction solutions by magnet adsorption and reused for at least four times. Therefore, the efficiency and recyclability of self-assembled FeIII-TAML/CTAB@Fe3O4 nanostructures will enable the application of FeIII-TAML-based materials with a lowered expense for environmental implication.

CTAB improves the performance of NiMoO4@NF grown NiCoZn-LDH for supercapacitor

Transition metal hydroxides have attracted wide attention as promising composite nanomaterials due to their numerous active sites and large specific surface areas. In this study, a two-step hydrothermal synthesis method is proposed to generate a heterostructure (NiCoZn-LDH@NiMoO4@NF) consisting of nanoflowers coated with nanoneedles on a foam nickel substrate. The aggregation issue of NiCoZn-LDH is effectively improved by immersing it in CTAB solution after one-step hydrothermal synthesis of NiMoO4 nanoneedles on Ni Foam (NF). The heterostructure between NiMoO4 nanoneedles and NiCoZn-LDH significantly enhances the material stability and electrochemical performance. Activated carbon is used as the negative electrode, and the NiCoZn-LDH@NiMoO4@NF composite material is used as the positive electrode to assemble an asymmetric supercapacitor (ASC) device for electrochemical testing. The device exhibits a specific capacitance of 3541 mF/cm2 at a current density of 6 mA/cm2. Furthermore, the capacity retention rate remains at 83.04 % after 10,000 cycles of charge and discharge, and a high specific energy density of 0.735 mWh/cm2 is achieved at a power density of 1.6 mW/cm2. The experimental results demonstrate that transition metal hydroxides play a crucial role in enhancing the electrochemical performance of supercapacitors. This study provides new insights into Supercapacitor (SC) active materials and offers a promising experimental approach for synthesizing new nanomaterials.

Flow Injection Sensing Strategy for Determining Cationic Surfactants in Commodity and Water Samples

The formation of stable binary water-soluble sub-micellar aggregates of cetyltrimethylammonium bromide-copper-pyrocatechol violet complex (CTAB-Cu-PCV) diminishes the stability and absorbance of the Cu-PCV complex. A new flow injection spectrophotometric sensing strategy used for the determination of CTAB in commodity personal care antiseptics and water samples has been established relying on the above-mentioned concept. Based on the reduction of the absorption of the Cu-PCV solution by the injection of CTAB solution at pH 6.0 and 430 nm, a linear absorbance decrease was observed over the CTAB concentration range of 2.0 to 100.0 µg mL−1 (r = 0.987). The analysis method showed limits of detection (3.3 ơ) and quantification (10 ơ) of 0.08 and 0.27 µg mL−1, respectively. The precision (RSD) for five replicate determinations was 7.9 and 3.7% at 10 and 50 µg mL−1, respectively. The developed method was applied successfully to the determination of CTAB in personal care products, namely skin lotion and vaginal wash, in addition to water samples. The corresponding RSD (n = 5) values were ≤8.2%.

Droplets Generation using Soluble Polymeric and Surfactant Additives in a Micro-Flow System: An Experimental Approach

In the present work, polymer and surfactant solutions (Xanthan Gum- Cetyltrimethylammonium bromide) were formulated and tested in a micro-flow system (microchannel) carrying octanoic acid as the hydrocarbon phase to determine the droplets formation capabilities of the two different additives. The purpose is to compare the droplet-generated size, shape, and distance between the droplets forming from the individual additives solutions. The jetting phenomenon that happens during droplet generation was also investigated. The solution of the polymer (XG) and surfactant (CTAB) was prepared in 5 different concentrations (50, 100, 150, 200, and 250) ppm and (500, 1000, 1500, 2000, and 2500) ppm, respectively. The continuous and dispersed phases' flow was controlled by controlling the inlet pressure of both phases. Direct-writing lithography was used to fabricate the microchannels using polydimethylsiloxane polymer. The microfluidic chip was connected to an open-loop fluid circulation system, and the produced by polymer and surfactant solutions droplets size was recorded using a high-resolution microscope. The droplet generated using the XG solution was larger, and the distance between droplets was shorter as concentration increased. In contrast, the CTAB solutions showed smaller droplets, and the distance between droplets increased as the concentration increased. The possibility of coalescence of the droplet was also higher as the distance between droplets was shorter. In terms of jetting regime, as the pressure ratio increases, the jet breakup length increases before forming the droplet until, at some limit, the dispersed phase was failed to generate droplets.

Molecular dynamics simulations of dodecane detachment from hydrophobic SiO2 surfaces in CTAB solutions

The oil detachment from solid surfaces has a major influence on enhanced oil recovery, self-cleaning performance, flotation efficiency, oil/water separation, and so on. In this paper, the mechanism of oil detachment from surfaces of different hydrophobicity was studied via molecular dynamics (MD) simulations. The oil detachment process becomes slower and the oil-solid contact angle is smaller with the increasing hydrophobicity of the silica surface. The simulation results showed that the disordered arrangement of oil molecules facilitated the formation of water channels on hydrophobic surfaces. Then, expansion of water channels becomes the key to oil detachment. The main driving forces are the Coulomb interactions and the H-bond formation between water and surface. The resistances are from hydrophobic effects by which the oil layer couldn’t be detached thoroughly from the hydrophobic surface. Data availability statementThe data that supports the findings of this study are available within the article and its supplementary material.

Comparison of two Genomic DNA Extraction Protocols from Single Dray Seed of Barley Crop

Modern plant breeding studies are largely based on plant genetic engineering programs. Extraction of DNA with high quality plays as a key factor in most of plant genetic Studies, therefore two different DNA extraction protocols based on CTAB buffer and SDS buffer were tested for the purpose of selecting the best DNA extraction protocol from dry seeds of nine variety of barely plant . Barley seeds were taken from Libyan seeds gene bank .After Barely samples were prepared DNA was extracted directly using CTAB and SDS solutions .The quality of extracted DNA was assessed by spectrophotometric measurements and gel electrophoresis system. The results of this study showed that purity of extracted DNA by CTAB method was clearly batter compared with SDS method. CTAB method seemed to be more effective for extracting DNA from barely dry seeds. High quality DNA obtained through use of CTAB method, while CTAB had overall better A260/A280 ratio (1.736-1.932). SDS method seemed to be not suitable for DNA extraction from dry seeds of barely crop.

Investigating Growth of Gold Nanorods by Simultaneous Small‐Angle X‐Ray and Neutron Scattering

Increased usage of gold nanorods (AuNRs) in various biosensing and medical applications requires tight size and morphology control. This is often achieved by tuning the aggregation behavior of the stabilizing ligand cetrimonium bromide (CTAB). Because the role of CTAB during AuNR growth is still a matter of debate, simultaneous small‐angle X‐ray and neutron scattering experiments (SAXS/SANS) and measurements are performed. The SAXS/SANS measurements have enabled an instantaneous correlation between the size of evolving AuNR and the nanostructure of guiding CTAB moieties. Upon modifying the aggregation behavior of CTAB micelles by adding hexanol or pentanol as inert additives in the precursor solution, a marked change in reaction kinetics is observed. Alcohol‐modified CTAB nanostructures have improved AuNR size uniformity compared to those prepared in alcohol‐free CTAB solutions, which are attributed to different growth modes. The change in reaction kinetics is linked to a changed stabilization mechanism of reactants and nascent AuNR facilitated by CTAB micelles.

Preparation of prismatic g-C3N4 by CTAB hydrothermal method and its degradation performance under visible light

In this paper, the growth mechanism of prismatic carbon nitride at different temperatures was studied by using the mixed solution of CTAB and NaOH by thermal polycondensation-hydrothermal method, and a series of characterization methods were used to analyze and verify. The pollutant model MO solution was degraded and its photocatalytic activity was investigated under light. The results show that at a relatively low temperature, g-C3N4 is a rod-like structure, and NaOH plays a major role. With the increase of temperature, CTAB plays a major role and can transport the primitives to form a rod, but also forms an ordered hydrophobic film on the crystal plane, which inhibits the growth of the rod-like structure on the (100) crystal plane and controls the extension on the (002) crystal plane. Its degradation rate is about 2.64 times that of pure g-C3N4. This significantly improves the separation rate of photogenerated electrons and the photocatalytic degradation efficiency.

Prediction of Aqueous Solution Surface Tension of Some Surfactant Mixtures and Composition of Their Monolayers at the Solution—Air Interface

Measurements of the surface tension of the aqueous solution of SDDS mixture with fluorocarbon surfactants (FC) were carried out and considered in light of the surface tension of aqueous solutions of individual surfactants. Similar analyses were made for many other aqueous solutions of binary and ternary mixtures, taking into account the literature data of the surface tension of aqueous solutions of TX100, TX114, TX165, SDDS, SDS, CTAB, CPyB and FC. The possibility of predicting the surface tension of the aqueous solution of many surfactant mixtures from that of the mixture components using both the Szyszkowski, Fainerman and Miller and Joos concepts was analyzed. The surface tension of the aqueous solutions of surfactant mixtures was also considered based on the particular mixture component contribution to the water surface tension reduction. As a result, the composition of the mixed surface layer at the solution–air interface was discussed and compared to that which was determined using the Hua and Rosen concept. As follows from considerations, the surface tension of the aqueous solution of binary and ternary surfactant mixtures can be described and/or predicted.

Повторное применение очищенного раствора цетилтриметиламмония бромида для синтеза золотых наностержней

We investigate the possibility of reusing CTAB solutions for repeated synthesis of gold nanorods. Three tasks have been solved. The first task is to clean the growth solutions from gold nanorods. The second task is to develop a method using a purified cetyltrimethylammonium bromide solution for repeated synthesis of gold nanorods with the same optical properties as in the initial synthesis. The third task is to test the possibility of management of the optical properties of nanorods during repeated synthesis. The polydispersity of nanorods has been estimated by form factor using developed mathematical model.

Computational Investigations of a pH-Induced Structural Transition in a CTAB Solution with Toluic Acid.

In this work, molecular dynamics simulations were performed to study the pH-induced structural transitions for a CTAB/p-toluic acid solution. Spherical and cylindrical micelles were obtained for aqueous surfactants at pH 2 and 7, respectively, which agrees well with the experimental observations. The structural properties of two different micelles were analyzed through the density distributions of components and the molecular orientations of CTA+ and toluic acid inside the micelles. It was found that the bonding interactions between CTA+ and toluic in spherical and cylindrical micelles are very different. Almost all the ionized toluic acid (PTA−) in the solution at pH 7 was solubilized into the micelles, and it was located in the CTA+ headgroups region. Additionally, the bonding between surfactant CTA+ and PTA− was very tight due to the electrostatic interactions. The PTA− that penetrated into the micelles effectively screened the electrostatic repulsion among the cationic headgroups, which is considered to be crucial for maintaining the cylindrical micellar shape. As the pH decreased, the carboxyl groups were protonated. The hydration ability of neutral carboxyl groups weakened, resulting in deeper penetration into the micelles. Meanwhile, their bonding interactions with surfactant headgroups also weakened. Accompanied by the strengthen of electrostatic repulsion among the positive headgroups, the cylindrical micelle was broken into spherical micelles. Our work provided an atomic-level insights into the mechanism of pH-induced structural transitions of a CTAB/p-toluic solution, which is expected to be useful for further understanding the aggregate behavior of mixed cationic surfactants and aromatic acids.

The solubilization of diphenyl diselenide in surfactant solutions

Solubilization of diphenyl diselenide (DPDS) was studied in CTAB, OPE-10 and SDS surfactant solutions at 298 K. Solubility of DPDS increases with increase in the surfactant concentration due to its solubilization in micelles. UV-Vis, H1 NMR and FT-IR spectroscopy was used to study the interaction, location of diphenyl diselenide in the micelle. The change in free energy for solubilization of DPDS in micellar media confirmed the favorable solubilizations in SDS, OPE-10 and CTAB solutions. The DPDS solubility was higher in OPE-10 and CTAB compared to SDS surfactant aqueous solutions.

Surface studies of the chemical environment in gold nanorods supported by X-ray photoelectron spectroscopy (XPS) and ab initio calculations

In this manuscript, we prepared gold nanorods (Au-NRs) through “silver-assisted seeded methodology” and studied their outermost layer using XPS spectroscopy and ab initio calculations to compare the chemical states of the constituents of the metallic core. Supporting first-principles calculations employing a relativistic, full-potential and all-electron method, with augmented plane waves plus local orbitals as a basis set, ensure proper treatment of the core electron states. Three significant findings can be reported. First, we found that besides Au (0), there are two chemical states for silver, namely Ag (0) and Ag(I), on the Au surface. Our results corroborate with recent results reported in the literature, indicating that Ag monolayer can be oxidized to Ag(I) during the steps of centrifugation and washing with diluted CTAB solution. Second, ab initio simulations showed that Ag atoms have different binding energies, depending on their configuration in Au-NRs (whether silver atoms are found on the surface or if they are spread in bulk as interstitial or substitutional defects). Third, theoretical studies showed that silver atoms located at interstitial sites could distort the crystalline structure, and, therefore, we do not expect interstitial Ag to occur in Au-NRs.

Preparation of 9,10-Bis(Phenylethynyl)anthracene and 1-Chloro-9,10-Bis(Phenylethynyl)anthracene nanoparticles using the laser processing in liquids: Influence of the surfactants on the optical properties

Laser processing of 9,10-bis(phenylethynyl)anthracene (BPEA) and 1-chloro-9,10-bis(phenylethynyl)anthracene (CBPEA) in the surfactant solutions of anionic SDS, cationic CTAB, and amphiphilic surfactants of HDDSA and TDDHSA were performed using the second-harmonic (532 nm) of pulsed Nd:YAG lasers. Using the present laser processing techniques, the generation of BPEA and CBPEA nanoparticles was succeeded for the first time. The optical properties of BPEA and CBPEA nanoparticles prepared by the laser processing techniques were measured and compared with the previous work prepared by the precipitation method. The pH dependence of the absorption spectra of BPEA and CBPEA obtained by the laser processing in the amphiphilic surfactants was also investigated and the results for such pH dependence of the absorption spectra were also reported.

Reversible isomerization of metal nanoclusters induced by intermolecular interaction

Reversible isomerization of metal nanoclusters induced by intermolecular interaction