Cationic Surfactant Research Articles

Electrochemical Measurements of the In(III) Ions Electroreduction; the Influence of Mixed Adsorption Layers ACT-CTAB and ACT-SDS

Using voltammetric and impedance methods, the effects of mixed adsorption layers ACT-CTAB and ACT-SDS on the kinetics and mechanism of In(III) ions electroreduction were investigated. Acetazolamide (ACT) was shown to catalyse the course of the electrode reaction (according to the cap-pair rule). The multi-step nature of the In(III) ions electroreduction process in each of the systems studied in the chemical step of formation of the active In(III) - ACT complexes in the adsorption layer playing an important role is demonstrated. The presence of the cationic surfactant CTAB increases the dynamics of acceleration of the In(III) ion electroreduction process by ACT, while the presence of the anionic surfactant SDS inhibits this reaction.

Surfactant Directionally Assembled at the Electrode-Electrolyte Interface for Facilitating Electrocatalytic Aldehyde Hydrogenation.

Electrocatalytic hydrogenation of unsaturated aldehydes to unsaturated alcohols is a promising alternative to conventional thermal processes. Both the catalyst and electrolyte deeply impact the performance. Designing the electrode-electrolyte interface remains challenging due to its compositional and structural complexity. Here, we employ the electrocatalytic hydrogenation of 5-hydroxymethylfurfural (HMF) as a reaction model. The typical cationic surfactant, cetyltrimethylammonium bromide (CTAB), and its analogs are employed as electrolyte additives to tune the interfacial microenvironment, delivering high-efficiency hydrogenation of HMF and inhibition of the hydrogen evolution reaction (HER). The surfactants experience a conformational transformation from stochastic distribution to directional assembly under applied potential. This oriented arrangement hampers the transfer of water molecules to the interface and promotes the enrichment of reactants. In addition, near 100 % 2,5-bis(hydroxymethyl)furan (BHMF) selectivity is achieved, and the faradaic efficiency (FE) of the BHMF is improved from 61 % to 74 % at -100 mA cm-2. Notably, the microenvironmental modulation strategy applies to a range of electrocatalytic hydrogenation reactions involving aldehyde substrates. This work paves the way for engineering advanced electrode-electrolyte interfaces and boosting unsaturated alcohol electrosynthesis efficiency.

Highly Efficient Cationic Surfactant Functionalized Alginate Hydrogel for Perfluorooctanoic Acid Adsorption: Optimization through Response Surface Methodology and Performance Evaluation for Aqueous Media

Highly Efficient Cationic Surfactant Functionalized Alginate Hydrogel for Perfluorooctanoic Acid Adsorption: Optimization through Response Surface Methodology and Performance Evaluation for Aqueous Media

Manipulating the hydrophilic / hydrophobic balance in novel cationic surfactants by ethoxylation: The impact on adsorption and self-assembly

HypothesisCationic surfactants have a wide range of applications, often associated with their affinity for a range of solid surfaces and their anti-microbial properties. Manipulating their adsorption and self-assembly properties is key to most applications, and this is commonly achieved through surfactant mixtures or manipulating their headgroup or alkyl chain structure. Achieving this through adjustments to their headgroup structure is less common in cationic surfactants than in anionic surfactants. Ethoxylation provides the ability to adjust the hydrophilic / hydrophobic balance, as extensively demonstrated in a range of anionic surfactants. ExperimentsThis same approach has been applied here to a range of ethoxylated cationic surfactants in the form of the quaternary ammonium salts, and their tertiary nonionic equivalents before quaternisation. Their adsorption and self-assembly properties are investigated using predominantly the neutron scattering techniques of neutron reflectivity, NR, and small angle neutron scattering, SANS. FindingsThe trends in the adsorption at the air–water interface and the self-assembly in aqueous solution demonstrate how the hydrophilic / hydrophobic balance can be adjusted by varying the degree of ethoxylation and the alkyl chain length, and illustrate the degree of interdependence of the different structural changes. The variation in the adsorption and the micelle structure shows how the surfactant conformation / packing changes as the degree of ethoxylation and alkyl chain length increases and how the introduction of charge induces further changes.

Evaluation of a novel paraffin wax microemulsion for improving wellbore stability in shale formations

High-performance shale stabilizers are urgently required to address the concerns of wellbore instability when drilling troublesome shale wells. Herein, a novel paraffin wax microemulsion (PM) containing cationic surfactant was prepared and evaluated for shale formations. The shale stability performance of PM was studied using shale pressure penetration test, shale swelling and dispersion test. The shale stabilization mechanism of PM was investigated by surface tension, contact angle, surface free energy, capillary tube rise and SEM tests. The experimental findings showed that the pressure penetration time in shale after treatment with PM was extended from 13 to 107 min. And PM could decrease the shale swelling rate by 41.5%, and increase the recovery rate to 89.4%. PM exhibited better sealing and inhibition properties than that of commonly used shale stabilizers. The mechanism research revealed that the nano-droplets in PM could freely penetrate into shale pores and cracks of different sizes to form an effective sealing membrane. The water contact angle reached 91.4° after treatment with PM and the surface energy was significantly reduced, effectively inhibiting surface hydration. Through decreasing the surface tension and changing the wettability, the capillary force experienced a noticeable decrease with further enhanced inhibition of shale hydration. Therefore, the application of PM for shale stabilization exhibited promising potential, suggesting its possible effective utilization in shale drilling.

Synergistic effects of an amphiphilic drug(propranolol hydrochloride) with cationic surfactants in an aqueous medium: A physicochemical study

The interactions of amphiphilic drug(propranolol hydrochloride, PPL) with cationic surfactants, such as dodecyltrimethylammoniumbromide(DTAB), tetradecyltrimethylammonium bromide (TTAB), trimethyltetradecylammonium chloride(TTAC) and tetyltrimethylammonium bromide(CTAB), in an aqueous medium were evaluated. The surface tension measurement was used to examine the mixed micellization behavior and surface properties of drug-surfactant mixtures. The nonideal or synergistic behaviors of the mixed systems were explored by using several physical models, such as Clint, Rubingh, Rosen, and Motomura models, based on regular solution theory and pseudophase approximation. In addition, the synergism between PPL and cationic surfactants was also confirmed using ultraviolet–visible spectroscopy. The stoichiometric ratios, binding constants, and free energy changes of the drug–surfactant mixtures were computed using Benesi–Hildebrand (B–H) theory.

The impact of cationic/anionic ratio on the physicochemical aspects of catanionic niosomes as a promising carrier for anticancer drugs

BackgroundNiosomes are adaptable nanocarriers for the delivery and controlled release of anticancer drugs. The addition of ionic surfactants could easily functionalize these carriers. Catanionic niosomes that are comprised of cationic and anionic surfactants are effective drug-delivery vehicles. Here, we aim to evaluate the impact of the cationic/anionic ratio on the noisome characteristics. MethodsA novel approach utilizing molecular modeling was utilized to analyze some characteristics of catanionic niosomes, showing great potential as a vehicle for anticancer drugs. The nonionic surfactant SPAN60, along with cholesterol as the stabilizer, was utilized in the study. Moreover, CTAB and SDS were used as positively and negatively charged surfactants, respectively. An FDA-approved c-Met inhibitor, cabozantinib, was selected as the drug. Several significant parameters associated with the cabozantinib molecule and its properties within the bilayer like hydrogen bonding, total energy, radius of gyration (Rgyr), diffusion coefficient, and radial distribution function (RDF). ResultsThe findings suggest that the cabozantinib’s hydrogen bonding plays a vital role in the drug’s movement through the bilayer. The CTAB-rich niosomes showed a higher number of hydrogen bonds compared to the SDS-rich formulations. The diffusion coefficient was in agreement with the number of H-bonding, and this value increased from 3.12 × 10-12 (m2/s) in CTAB-rich niosome to 7.66 × 10-12 (m2/s) in SDS-rich niosime. ConclusionThe total binding energy between the drug and bilayer components can control drug release. The computational approach could sufficiently describe the influence of cationic/anionic molar ratios on the bilayer features, and the characteristics of catanionic niosomes could be easily adjusted for the controlled release of anticancer drugs.

Influence study of cationic surfactant, temperature, and current on the electrocoagulation process for removal of Remazol Red RB 133 by central composite design and response surface methodology

Influence study of cationic surfactant, temperature, and current on the electrocoagulation process for removal of Remazol Red RB 133 by central composite design and response surface methodology

Voltammetric determination of the antifungal drug posaconazole in the presence of an anionic surfactant on a boron-doped diamond electrode

This study describes a new, fast and simple procedure of electrochemical assay of posaconazole (PCZ), which is currently regarded as one of the most important antifungal agents, recommended in the treatment of systemic infections, effective even against rare and atypical kinds of fungi. PCZ is very effective and safe, displaying much lower toxicity than other traditional antifungal drugs. A new, attractive procedure of assaying the compound on boron-doped diamond (BDD) electrode after cathodic pretreatment in the presence of sodium dodecyl sulfate (SDS) is presented in the work. The anionic surfactant SDS was selected after the comparative analysis of various cationic surfactants. PCZ gave a single irreversible oxidation peak at the potential of 0.59 V. The addition of SDS resulted in an almost 5-fold growth in the value of recorded currents as compared to those observed in the absence of the surfactant. The highest peak was obtained in Britton-Robinson buffer at pH 3.78. The calibration curve of PCZ plotted using the SWV technique was linear in the concentration range from 1.34·10−8 mol/L to 1.44·10−6 mol/L. The limit of detection and limit of quantification were 3.78·10−9 mol/L and 1.14·10−8 mol/L, respectively. The value of relative standard deviation of the measurements did not exceed 4.42 %, which proves good precision of the proposed method. The proposed procedure was successfully used in assaying PCZ in simulated gastric juice.

Effect of Temperature on the Removal of Interferences in the Voltammetric Procedure for the Determination of Cr(VI).

The aim of this paper was to investigate the effect of temperature on the removal efficiency of surfactant-induced interferences. Surfactants were removed as a result of mixing with XAD-7 resin. The study was carried out using the example of Cr(VI) determination by adsorption stripping voltammetry (AdSV). Measurements were carried out using a solution containing Cr(VI), acetate buffer (pH = 6.2), DTPA, KNO3, and different surfactants. Ten mL of the solution was mixed with 0.5 g of XAD-7 resin at different temperatures for 5 min prior to voltammetric measurement. The effect of the mixing temperature of the sample with the resin on the voltammetric Cr(VI) signal in the presence of different surfactants was studied in the range from 20 to 60 °C. The proposed method of removing interference from surfactants by mixing the sample with the XAD-7 resin at 60 °C was used for the determination of trace amounts of Cr(VI) in river water containing non-ionic, anionic, cationic surfactants, and biosurfactants.

Surfactant-modified coconut coir powder (SMCCP) as a low-cost adsorbent for the treatment of dye-contaminated wastewater: parameters and adsorption mechanism.

The dye-contaminated wastewater discharged from various industries such as dye manufacturing, paint, textile, paper, and cosmetic is a prime source of surface water pollution having serious detrimental effects on both the environment and human beings. These hazardous dyes when exposed to water obstruct the penetration of sunlight into the water and thus restrain aquatic plants from generating photosynthetic compounds. Moreover, some dyes are potential cancer-causing and also negatively impact the human nervous and respiratory systems. In this current study, modification of coconut coir powder (CCP) was carried out through cationic surfactant treatment and was successively utilized as the adsorbent for decoloring anionic dye (acid blue 185 (AB 185)) containing waste stream. Further, a comparative investigation of the dye removal efficiency of raw CCP and surfactant-modified coconut coir powder (SMCCP) as the adsorbent was studied. On surfactant treatment, using a very minimal SMCCP dosage of 8.3g/L, a very high percentage dye removal of 98.4% is possible, whereas with raw CCP, even after using a higher dosage of 14g/L, only 70.1% dye removal can be achieved. Characterization of SMCCP adsorbent was done by Fourier transform infrared, thermogravimetric, X-ray, and scanning electron microscope analyses. Furthermore, the optimization of critical operating parameters was investigated for the effective adsorption of AB 185 dye in batch mode. The adsorption of AB 185 onto SMCCP was a thermodynamically spontaneous endothermic process, following the Langmuir isotherm and pseudo-second-order kinetic model. Moreover, regeneration of exhausted SMCCP by 0.1 (M) NaOH was achieved with a satisfactorily high recovery of 97% in the first cycle. Subsequently, SMCCP can be successfully reutilized for five consecutive cycles with a loss of 17.6% in the total adsorption capacity. With all such advantages, the present study delivers a new paradigm to utilize the novel adsorbent SMCCP as a promising eco-friendly adsorbent aided by its advantage of regeneration and reusability for the treatment of dye-contaminated wastewater.

Machine learning prediction and optimization of CO2 foam performance for enhanced oil recovery and carbon sequestration: Effect of surfactant type and operating conditions

Foam flooding handles the challenges of gas injection constituting a high viscosity medium that sweeps oil more efficiently meanwhile creating a barrier that prevents leakage of gas phase. Therefore, it is a promising enhanced oil recovery (EOR) method, simultaneously an efficient carbon dioxide (CO2) storage technology. The foam's performance displays susceptibility to various reservoir and operational parameters. Numerous laboratory experiments would need to be carried out to study foams and find the optimum foam formulation for the given core conditions. Data-driven approaches can be an alternative method to the time-consuming experimental and conventional modeling techniques, which often face challenges to incorporate the effect of important related parameters such as temperature and type of surfactant to the performance of foam. In the current study, machine learning (ML) models were constructed to predict the CO2 foam apparent viscosity in carbonate and sandstone formations focusing on experimental data from the literature for CO2 foams stabilized by different surfactants. Various anionic, cationic, and nonionic surfactants were considered and characterized based on the hydrophilic-lipophilic balance (HLB) number. Predictive models were developed using ML algorithms based on the data available for eight key process parameters. Artificial neural networks and extra randomized tree algorithms provided the most precise prediction among the applied algorithms. Various predictions for foam apparent viscosity on hypothetical case studies were made on altered input parameters, enabling CO2 mobility to co-optimize EOR and CO2 sequestration while selecting the optimum surfactant for each case.

Impact of cationic surfactants molecular structure on physicochemical structure and properties of polyamide reverse osmosis membrane via tailoring interfacial polymerization

Surfactants assisted interfacial polymerization (IP) has been demonstrated as an effective method to finely tailor the structure and performance of polyamide (PA) reverse osmosis (RO) membranes. However, little is done to illustrate how molecular structure of cationic surfactants affects IP and the amounts of surfactants incorporated into PA. In this study, three types of quaternary ammonium cationic surfactants were employed to assist the IP process and to fabricate RO membranes. Results show that these three cationic surfactants can not only significantly accelerate m-phenylenediamine (MPD) diffusion from aqueous phase into oil phase and promote the PA crosslinking, but also can be incorporated into PA to affect the surface properties (hydrophilicity, charge properties). Benzyl dimethyl phenyl ammonium chloride (BDMPAC) having two benzene rings had been found to be incorporated into PA with the highest amount because of its similar benzene structure as PA. Moreover, benzalkonium chloride (BAC) with the longest aliphatic tail induced a pronounced Marangoni convection during IP, resulting in an enlarged surface area of PA with large leaves and abundant internal/backside voids, and thus the highest water permeance. This study demonstrates a facile and simple way of using cationic surfactants to engineer the high-performance polyamide RO membrane.

Structure–property relationships of cationic polyurethane surfactants: Impact on surface activity and anticorrosion performance

Three cationic polyurethane surfactants (LC1–1, LC2–2, and LC2–3), each featuring different hydrophobic structures, were synthesized using isophorone diisocyanate, N-methyl diethanolamine, 1-bromohexadecane, and 1-bromobutane. The synthesized cationic polyurethane surfactants exhibited low surface tension, excellent foaming properties, and resistance to salt, attributed to steric hindrance among long-chain alkyl groups and their “multi-point anchoring” ability. The corrosion inhibition performance of polyurethane surfactants on carbon steel in 1 M HCl solution was evalutated, and LC2–2 showing a considerable corrosion inhibition efficiency of 97.0 %. This film effectively reduced/isolated contact between the corrosive solution and the steel interface. Furthermore, quantum chemical calculations corroborated the electrochemistry experiment results, affirming that the molecular structure of LC2–2 is particularly conducive to inhibiting the corrosion of carbon steel. This study explores the relationship between the molecular structure of surfactants and its impact on both surface activity and corrosion inhibition efficiency.

Highly Efficient Removal of 2,4,5-Trichlorophenoxyacetic Acid by Adsorption and Photocatalysis Using Nanomaterials with Surface Coating by the Cationic Surfactant.

Extensive removal of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) using titania (TiO2) nanoparticles by adsorption and photocatalysis with a surface coating by cetyltrimethylammonium bromide (CTAB) is reported. The CTAB-coated TiO2 nanoparticles (CCTN) were characterized by FT-IR, zeta-potential measurements, and UV-vis diffuse reflectance spectroscopy (UV-vis-DRS). 2,4,5-T removal increased significantly after surface modification with CTAB compared with bare TiO2 nanoparticles. Optimal parameters affecting 2,4,5-T removal were found to be pH 4, CCTN dosage 10 mg/mL, and adsorption time 180 min. The maximum adsorptive removal of 2,4,5-T using CCTN reached 96.2% while highest adsorption capacity was 13.4 mg/g. CCTN was also found to be an excellent photocatalyst that achieved degradation efficiency of 99.2% with an initial concentration of 25 mg/L. The removal mechanisms of 2,4,5-T using CCTN by both adsorption and photocatalysis are discussed in detail based on changes in functional group vibrations and surface charge. Our results indicate that CCTN is an excellent material for 2,4,5-T removal in water by both adsorption and photocatalysis.

Structural Characteristics, Electronic Properties, and Coupling Behavior of 12-4-12, 12-3-12, 12-2-12 Cationic Surfactants: A First-Principles Computational Investigation and Experimental Raman Spectroscopy

In this study, we present a comprehensive first-principles computational investigation focused on the structural characteristics, electronic properties, and coupling integrations of three cationic Gemini surfactants: 12-4-12, 12-3-12, and 12-2-12 ((CH3(CH2)11)(CH3)2-N+-(CH2)n-N+(CH3(CH2)11)(CH3)2, where n = 2, 3, or 4). By employing Density Functional Theory (DFT) computations, we aimed to gain insights into the fundamental aspects of these surfactant molecules, and the intermolecular interactions among these surfactant molecules. We examined different conformers of each surfactant, including parallel, wing, and bent conformers, and compared their relative stability and properties. We elucidated that the complex structural characteristics, electronic properties, and molecular arrangements of the surfactants vary according to the number of carbon atoms in the central spacer. We also conducted experimental Raman spectroscopy on the three surfactants to compare the results with our computational findings. Furthermore, we computed the coupling behaviors of different conformers of 12-4-12 surfactants in order to gain insights into their coupling mechanism.

Synergistic corrosion inhibition effect of N-benzyl pyridinium chloride and three cationic surfactants in the H2S/CO2/NaCl solution

The investigation into the synergistic corrosion inhibition effects of N-benzyl pyridinium chloride (BPC) and three cationic surfactants (i.e., dodecyl trimethyl ammonium bromide, tetradecyltrimethyl ammonium bromide and cetyltrimethyl ammonium bromide) in H2S/CO2/NaCl solution was conducted using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy, scanning electron microscopy, surface tension and X-ray photoelectron spectroscopy. Corrosion inhibition efficiencies of these surfactants correlated to their surface activity levels. Notably, the addition of BPC significantly improved the protective effectiveness of surfactants, demonstrating a strong synergistic inhibitory impact. The enhancement is attributed to the co-adsorption of the surfactants with BPC, which effectively covers the flaws in BPC adsorbed layer. This increases the overall coverage of inhibitive film, thereby offering high inhibition efficiencies for carbon steel in the tested environment.

An application of hierarchical MgAl hydrotalcite in the highly efficient treatment of oilfield macromolecular contaminants.

In this work, salicylic acid (SA) was used to induce the self-assembly of octadecyl trimethyl ammonium chloride (OTAC), a cationic surfactant, into three-dimensional wormlike micelle aggregates. These aggregates act as a soft template for hierarchical MgAl hydrotalcite (LDH) to create a multi-level pore structure adsorption material. Scanning electron microscopy characterization showed that the surface of the hierarchical hydrotalcite exhibited a dense layered structure, unlike the monolayer structure of ordinary hydrotalcite. Furthermore, the hierarchical MgAl-LDH possesses a significantly larger specific surface area (113.94 m2/g) and wide pore size distribution ranging more extensively from 2 to 80nm, which significantly has an impressive adsorption effect on sulfonated lignite (SL), with a maximum adsorption capacity of 192.7mg/g at pH = 7. Extensive research has been conducted on the adsorption mechanism of hierarchical MgAl-LDH, attributing it to surface adsorption due to the unique multi-level structure of the adsorbent. After two cycles of regeneration experiments, the adsorption capacity of the adsorbent remained at a high level of 179.1mg/g, demonstrating the excellent renewability of hierarchical MgAl-LDH. Moreover, the hierarchical hydrotalcite showed high adsorption capacity in the adsorption of sulfonated lignite, which was attributed to its larger specific surface area and superior pore structure to expose more active sites.

Surface chemistry engineered selenium nanoparticles as bactericidal and immuno-modulating dual-functional agents for combating methicillin-resistant Staphylococcus aureus Infection

Because of the extremely complexed microenvironment of drug-resistant bacterial infection, nanomaterials with both bactericidal and immuno-modulating activities are undoubtedly the ideal modality for overcoming drug resistance. Herein, we precisely engineered the surface chemistry of selenium nanoparticles (SeNPs) using neutral (polyvinylpyrrolidone-PVP), anionic (letinan-LET) and cationic (chitosan-CS) surfactants. It was found that surface chemistry greatly influenced the bioactivities of functionalized SeNPs, their interactions with methicillin-resistant Staphylococcus aureus (MRSA), immune cells and metabolisms. LET-functionalized SeNPs with distinct metabolisms exhibited the best inhibitory efficacy compared to other kinds of SeNPs against MRSA through inducing robust ROS generation and damaging bacterial cell wall. Meanwhile, only LET-SeNPs could effectively activate natural kill (NK) cells, and enhance the phagocytic capability of macrophages and its killing activity against bacteria. Furthermore, in vivo studies suggested that LET-SeNPs treatment highly effectively combated MRSA infection and promoted wound healing by triggering much more mouse NK cells, CD8+ and CD4+ T lymphocytes infiltrating into the infected area at the early stage to efficiently eliminate MRSA in the mouse model. This study demonstrates that the novel functionalized SeNP with dual functions could serve as an effective antibacterial agent and could guide the development of next generation antibacterial agents.

Antimicrobial and Anesthetic Niosomal Formulations Based on Amino Acid-Derived Surfactants.

This work proposes the development of new vesicular systems based on anesthetic compounds (lidocaine (LID) and capsaicin (CA)) and antimicrobial agents (amino acid-based surfactants from phenylalanine), with a focus on physicochemical characterization and the evaluation of antimicrobial and cytotoxic properties. Phenylalanine surfactants were characterized via high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR). Different niosomal systems based on capsaicin, lidocaine, cationic phenylalanine surfactants, and dipalmitoyl phosphatidylcholine (DPPC) were characterized in terms of size, polydispersion index (PI), zeta potential, and encapsulation efficiency using dynamic light scattering (DLS), transmitted light microscopy (TEM), and small-angle X-ray scattering (SAXS). Furthermore, the interaction of the pure compounds used to prepare the niosomal formulations with DPPC monolayers was determined using a Langmuir balance. The antibacterial activity of the vesicular systems and their biocompatibility were evaluated, and molecular docking studies were carried out to obtain information about the mechanism by which these compounds interact with bacteria. The stability and reduced size of the analyzed niosomal formulations demonstrate their potential in pharmaceutical applications. The nanosystems exhibit promising antimicrobial activity, marking a significant advancement in pharmaceutical delivery systems with dual therapeutic properties. The biocompatibility of some formulations underscores their viability. The proposed niosomal formulations could constitute an important advance in the pharmaceutical field, offering delivery systems for combined therapies thanks to the pharmacological properties of the individual components.