Effect Of Surfactants Research Articles

Tuning capacitance of bimetallic ZnCo2O4 using anionic, cationic and non-ionic surfactants by hydrothermal synthesis for high-performance asymmetric supercapacitor

Surface properties of nanomaterials are directly related to their electrochemical performance, with surfactants playing an essential role in their cost-effective synthesis as structure-directing agents and templates. This research article discusses the effects of neutral, cationic, and anionic surfactants on the capacitance of bimetallic ZnCo2O4 nanomaterial, synthesized via a straightforward hydrothermal-annealing method. We investigated how cationic (cetyl-trimethyl ammonium bromide), anionic (sodium dodecyl sulphate), and non-ionic (urea) surfactants influence the electrochemical characteristics of ZnCo2O4 nano-powders. All three surfactant-based ZnCo2O4 electrodes exhibited Faradaic behaviour during electrochemical tests. The ionic nature of the surfactants significantly impacted the charge-storage mechanism, with specific capacitance values rising in the order of Urea (550 Fg−1) < C-TAB (740 Fg−1) < SDS (980 Fg−1) at a 1 Ag−1 in half-cell studies. The ZnCo2O4-SDS displayed the highest surface redox reactivity and superior electrochemical performance, with 426 Fg−1 in full-cell studies, energy density of 230 WhKg−1 (1 Ag−1), power density of 18,213.9 WKg−1 (10 Ag−1), and 93 % capacitance retention is observed over 50,000 cycles (50 Ag−1).

Analysis of the Effect of Surfactants on the Performance of Apatite Column Flotation

Given that particle and bubble size, as well as their surface properties, are pivotal in froth flotation, surfactants have been extensively employed due to their impact on bubble size and froth stabilization. This study aimed to investigate the influence of surfactants on the performance of apatite flotation in column. Three different categories of surfactants were examined: anionic, amphoteric, and nonionic, specifically Lupromin, Genagen, and Triton X-100, respectively. The critical coalescence concentration (CCC) and surface tension of each surfactant were determined. The impact of these surfactants on reducing bubble size was quantified, and their subsequent effects on apatite flotation in a column were assessed. The most favorable flotation response for Genagen was achieved at CCC and pH 11, resulting in the highest apatite recovery and the smallest bubble size. For Triton X-100, the best condition was attained at ¼ CCC and pH 11. However, overall, Lupromin was the surfactant that yielded the best flotation results (at ¼ CCC and pH 11). The superior performance of this anionic surfactant was corroborated by chemical adsorption results, as demonstrated by FTIR analyses.

Effects of surfactants on the morphologies, structures, and electrochemical activities of WO3/Ag2O nanocomposites for supercapacitor electrodes

For energy storage, supercapacitors have been extensively developed. Among them, pseudocapacitors that use faradaic reactions of conductive polymers and transition metal oxides exhibit high electrochemical performance. In this study, WO3-based electrodes for high-performance pseudocapacitors were designed with Ag2O and various surfactants, with the aim to extend of the potential range and shape control of WO3 crystals. The WO3/Ag2O nanocomposites were prepared on a carbon cloth via chemical bath deposition with different types of surfactants: cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and Pluronic F-127. Both Ag and the surfactants affected the morphology of the WO3 crystals; their crystal sizes were decreased, and the crystallinity was improved. The specific capacitance of the WO3/Ag2O nanocomposite was 621 F/g at 5 mV/s, whereas that of WO3 was 397 F/g. Furthermore, the specific capacitance of the nanocomposites increased with the use of surfactants: 960 F/g for WO3/Ag2O@Pluronic F-127, 641 F/g for WO3/Ag2O@CTAB, and 846 F/g for WO3/Ag2O@SDS at 5 mV/s. WO3/Ag2O@Pluronic F-127 had superior capacitance and exhibited a charge/discharge capacitance retention rate of 135 % after 2000 cycles at 5 A/g. The symmetric electrode configuration of WO3/Ag2O@Pluronic F-127 exhibited a maximum energy density of 85 W h kg−1 and a power density of 670 W kg−1. These results highlight the significant potential of the WO3/Ag2O@Pluronic F-127 nanocomposite electrode for future energy storage devices.

Effects of pulmonary surfactant combined with noninvasive positive pressure ventilation in neonates with respiratory distress syndrome.

Neonatal respiratory distress syndrome (NRDS) is one of the most common diseases in neonatal intensive care units, with an incidence rate of about 7% among infants. Additionally, it is a leading cause of neonatal death in hospitals in China. The main mechanism of the disease is hypoxemia and hypercapnia caused by lack of surfactant. To explore the effect of pulmonary surfactant (PS) combined with noninvasive positive pressure ventilation on keratin-14 (KRT-14) and endothelin-1 (ET-1) levels in peripheral blood and the effectiveness in treating NRDS. Altogether 137 neonates with respiratory distress syndrome treated in our hospital from April 2019 to July 2021 were included. Of these, 64 control cases were treated with noninvasive positive pressure ventilation and 73 observation cases were treated with PS combined with noninvasive positive pressure ventilation. The expression of KRT-14 and ET-1 in the two groups was compared. The deaths, complications, and PaO2, PaCO2, and PaO2/FiO2 blood gas indexes in the two groups were compared. Receiver operating characteristic curve (ROC) analysis was used to determine the diagnostic value of KRT-14 and ET-1 in the treatment of NRDS. The observation group had a significantly higher effectiveness rate than the control group. There was no significant difference between the two groups in terms of neonatal mortality and adverse reactions, such as bronchial dysplasia, cyanosis, and shortness of breath. After treatment, the levels of PaO2 and PaO2/FiO2 in both groups were significantly higher than before treatment, while the level of PaCO2 was significantly lower. After treatment, the observation group had significantly higher levels of PaO2 and PaO2/FiO2 than the control group, while PaCO2 was notably lower in the observation group. After treatment, the KRT-14 and ET-1 levels in both groups were significantly decreased compared with the pre-treatment levels. The observation group had a reduction of KRT-14 and ET-1 levels than the control group. ROC curve analysis showed that the area under the curve (AUC) of KRT-14 was 0.791, and the AUC of ET-1 was 0.816. Combining PS with noninvasive positive pressure ventilation significantly improved the effectiveness of NRDS therapy. KRT-14 and ET-1 levels may have potential as therapeutic and diagnostic indicators.

Effect of a Natural Surfactant (Fenugreek Seeds) on Emulsification and Mobilization of Paraffins via Pore-Scale Micromodel Experiments.

The surface characteristics of minerals have been crucial in predicting the interactions between chemicals, particularly in chemical flooding. Thus, this paper evaluates the viability of natural surfactants derived from agricultural products for oil recovery studies using a micromodel filled with paraffinic oil. The study investigates the interfacial tension, viscosity, microscopic, dilution, and oil mobilization characteristics of the natural surfactants. The experimental setup involves conducting interfacial tension measurements between the surfactant solution and paraffinic oil using the Wilhelmy plate method and was found to be 14.2, 10.92, and 9.8 mN/m. Additionally, viscosity measurements and frequency sweep analysis were performed to assess the rheological properties of the prepared emulsion, which was stabilized using a natural surfactant. Microscopic evaluation depicts that, among the prepared emulsions, n-heptane emulsion seems more stable at both 30 and 90 °C. Moreover, dilution studies were conducted for each emulsion system, and the dilution ratio was varied from 1:5 to 1:1 (emulsion/saline solution). It was found that n-heptane emulsion possesses better stability at higher dilution (until a 3:5 ratio). Oil mobilization studies are conducted using a glass micromodel to simulate reservoir conditions and observe the displacement efficiency of the surfactant solutions. The results indicate that natural surfactants exhibit competitive interfacial tension reduction and viscosity modification properties compared to commercial surfactants. Furthermore, oil mobilization studies demonstrate the effectiveness of natural surfactants in enhancing oil recovery from paraffinic oil reservoirs. These findings suggest the potential of natural surfactants derived from agricultural products as sustainable alternatives for improving the oil recovery efficiency in petroleum reservoirs.

Thermoresponsiveness Across the Physiologically Accessible Range: Effect of Surfactant, Cross-Linker, and Initiator Content on Size, Structure, and Transition Temperature of Poly(N-isopropylmethacrylamide) Microgels.

The influence of surfactant, cross-linker, and initiator on the final structure and thermoresponse of poly(N-isopropylmethacrylamide) (pNIPMAM) microgels was evaluated. The goals were to control particle size (into the nanorange) and transition temperature (across the physiologically accessible range). The concentration of the reactants used in the synthesis was varied, except for the monomer, which was kept constant. The thermoresponsive suspensions formed were characterized by dynamic light scattering, small-angle X-ray scattering, atomic force microscopy, and rheology. Increasing surfactant, sodium dodecyl sulfate content, produced smaller microgels, as expected, into the nanorange and with greater internal entanglement, but with no change in phase transition temperature (LCST), which is contrary to previous reports. Increasing cross-linker, N,N-methylenebis acrylamide, content had no impact on particle size but reduced particle deformability and, again contrary to previous reports of decreases, progressively increased the LCST from 39 to 46 °C. The unusual LCST trends were confirmed using different rheological techniques. Initiator, potassium persulfate, content was found to weakly influence the outcomes. An optimized content was identified that provides functional nanogels in the 100 nm (swollen) size range with controlled LCST, just above physiological temperature. The study contributes chemistry-derived design rules for thermally responsive colloidal particles with physiologically accessible LCST for a variety of biomedical and soft robotics applications.

Effect of sucrose fatty acid ester on crystal growth of carbon dioxide hydrate in aqueous fructose solution

CO2 hydrate is a remarkable candidate for novel solid carbonated foods because of its large gas capacity. This paper reports the effect of surfactants, essential additives in food production, on hydrate crystal growth by visually observing the CO2 hydrate crystal growth in aqueous fructose + sucrose fatty acid ester solution + gaseous CO2 system. Under all thermodynamic conditions, the surfactants affected the crystal growth of CO2 hydrates at liquid/gas interface, while not influencing growth in the liquid bulk phase. Porous hydrate crystals were formed at the liquid/CO2 interface and grew continuously along the reactor wall. The hydrate crystal morphology in liquid bulk phase was not affected by surfactants, changing from polyhedral and polygonal to dendritic shapes as temperature decreased. Discussion is provided on how the observation results can be specifically applied to intensification of hydrate formation process design and evaluation of hydrated food texture.

Examining the Interplay of Hydrolysed Polyacrylamide and Sodium Dodecyl Sulfate on Emulsion Stability: Insights from Turbiscan and Electrocoalescence Studies.

Enhanced oil recovery (EOR) is utilized in the oil and gas production industry to extract additional oil from underground reservoirs. In chemically enhanced oil recovery, surfactant and polymeric water are injected separately or in a mixture. Injected fluids can form stable emulsions during oil production. This surfactant, polymer-loaded water-in-oil emulsion, must be separated to treat crude oil and avoid any corrosion or deactivation of catalysts in the refinery. An electrocoalecer technique is utilized to separate the water from the emulsion under the application of an electric field. To improve the efficiency of the EOR and electrocoalescers, it is essential to investigate the impact of surfactants, polymers, and their mixture interaction. In this study, the effects of surfactant (sodium dodecyl sulfate (SDS)), polymer (hydrolyzed polyacrylamide (HPAM)), and their mixture with a wide range of concentrations were analyzed using turbiscan, bottle electrocoalecer, interfacial tension (IFT), and conductivity. Our study shows that when SDS was used independently, the viscosity of the dispersed phase did not change. Surprisingly, when SDS was combined with HPAM, the overall viscosity of the dispersed phase mixture decreased. HPAM and SDS contribute to an increase in the conductivity of the dispersed phase. Conductivity, IFT, and viscosity are critical factors in studying electrocoalescence. Our detailed study found that SDS is the primary factor in stabilizing the emulsion compared to HPAM using turbiscan. The electrocoalecer study shows that in the case of a deionized water-based emulsion, the separation efficiency is 98% in 10 min. In contrast, a mixture of HPAM polymer with a concentration of 2000 ppm and SDS with a concentration of 5000 ppm stabilized emulsion shows 84% separation in 10 min. The outcome of this study helps design the electrocoalescer for separating complex water-in-oil emulsion.

The effect of varasurf surfactant on respiratory distress syndrome in rats

The effect of varasurf surfactant on respiratory distress syndrome in rats

Effect of surfactants and implementation strategies for the pentachlorophenol degradation with Ni/Fe bimetallic nanoparticles in soil

Pentachlorophenol (PCP) removal was found to be dependent on many factors including soil surface charge, Ni/Fe nanoparticle (NP) dosage, pH, and types of surfactants. Desorption efficiencies of PCP from the contaminated soil treated with DI water, cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and Triton X-100 (TX-100) were 88.2%, 1.35%, 103%, and 80.9%, respectively. PCP desorption was significantly enhanced by anionic SDS but reduced by cationic CTAB. PCP desorption efficiency was governed by van der Waals attraction and electrostatic interaction among surfactants, soil particles, and Ni/Fe nanoparticles. For SDS-modified Ni/Fe NPs, SDS bilayers form on the positively charged Ni/Fe surface to sterically and electrostatically stabilize Ni/Fe and enhance the PCP removal efficiency of Ni/Fe in soil. However, an opposite effect was observed in the CTAB-modified Ni/Fe. In the soil slurry, CTAB was readily detached from Ni/Fe and subsequently form a CTAB bilayer on the soil surface to adsorb PCP at the soil surface that significantly reduce PCP degradation by blocking PCP from accessing the Ni/Fe reactive sites although the Ni/Fe-CTAB exhibited extremely high reactivity for PCP in soil solutions. Based on the results, remediation strategies using a combination of surfactants and Ni/Fe bimetallic nanoparticles for ex-situ soil remediation were proposed.

Factors influencing airway smooth muscle tone: a comprehensive review with a special emphasis on pulmonary surfactant.

A thin film of pulmonary surfactant lines the surface of the airways and alveoli, where it lowers the surface tension in the peripheral lungs, preventing collapse of the bronchioles and alveoli and reducing the work of breathing. It also possesses a barrier function for maintaining the blood-gas interface of the lungs and plays an important role in innate immunity. The surfactant film covers the epithelium lining both large and small airways, forming the first line of defense between toxic airborne particles/pathogens and the lungs. Furthermore, surfactant has been shown to relax airway smooth muscle (ASM) after exposure to ASM agonists, suggesting a more subtle function. Whether surfactant masks irritant sensory receptors or interacts with one of them is not known. The relaxant effect of surfactant on ASM is absent in bronchial tissues denuded of an epithelial layer. Blocking of prostanoid synthesis inhibits the relaxant function of surfactant, indicating that prostanoids might be involved. Another possibility for surfactant to be active, namely through ATP-dependent potassium channels and the cAMP-regulated epithelial chloride channels [cystic fibrosis transmembrane conductance regulators (CFTRs)], was tested but could not be confirmed. Hence, this review discusses the mechanisms of known and potential relaxant effects of pulmonary surfactant on ASM. This review summarizes what is known about the role of surfactant in smooth muscle physiology and explores the scientific questions and studies needed to fully understand how surfactant helps maintain the delicate balance between relaxant and constrictor needs.

Investigation of the Effect of SCA Surfactant on Enhanced Oil Recovery Using Glass Micromodel

Investigation of the Effect of SCA Surfactant on Enhanced Oil Recovery Using Glass Micromodel

Synthesis and characterization of hierarchically mesoporous silica nanoparticles templated by polymer-surfactant complexes

The mesomorphous complex of poly(acrylic acid) and cationic surfactant as templates are widely used to prepare hierarchically meso-structured materials. Here, the effects of different cationic surfactant in complexes on the morphology and nano-structure of the mesoporous silica materials were studied. It was found chain length of hydrophobic tail significantly affected the meso-structure. With the increase of the chain length, three different of meso-structure of disordered, 3-dimentional cubic ordered, 2-dimentional hexagonal could be achieved. Significantly, the hierarchically mesoporous silica nanoparticles (50–100 nm) with 2-dimentional hexagonal meso-structure (P6mm) were firstly obtained in polymer-surfactant synthetic system.

The Effect of Surfactants on Double-Layer Capacitance Induced by Electric Fields

The Effect of Surfactants on Double-Layer Capacitance Induced by Electric Fields

Effect of surfactants on enzymatic hydrolysis of PET

Enzyme is difficult to adsorb on the surface of high-crystallinity poly(ethylene terephthalate) fibers (PET，crystallinity of 48.56 %) due to the high hydrophobicity of PET fibers. Surfactants can effectively reduce the PET/water interface tension and improve the adsorption of enzyme on PET fibers, increasing the degradation of PET fibers promoted by enzyme. In this paper, different nonionic surfactants (Triton X-100, Triton X-114, Triton X-405, PEG 200, PEG 400, PEG 600, Tween 20, Tween 80) were selected to investigate the effect of surfactant on the degradation of PET fibers by enzyme. It was found that the addition of Triton X-405 can improve the concentration of degradation products. However, other surfactants selected in this paper, such as Tween-80 caused the decrease of the degradation yields. The results indicated that the structure of surfactant plays a very important roll on the degradation of PET catalyzed by enzyme. This is probably due to the transformation of enzyme conformation induced by surfactant, and affects on the activity of enzyme. The hydrophilic surface is beneficial to the adsorption of enzyme onto the surface of PET fibers, and further improve the degradation of PET fibers.

Effect of surfactant and PAM on the settlement of kaolinite particles and its mechanism analysis

High concentrations of fine-grained clay minerals in tailings water are highly detrimental to environmental protection and water recycling. Using kaolinite as the study subject, this research investigates the effects of various cationic surfactants (DDA, DTAB, TTAB, CTAB) and flocculants (APAM, NPAM, CPAM) on the sedimentation of kaolinite particles. The study explores the impact of single agents, combined agents, and the sequence of their addition on kaolinite particle sedimentation. The results indicate that when using individual agents at low concentrations, CTAB outperforms TTAB, DTAB, and DDA, while APAM is more effective than NPAM and CPAM. The optimal performance is achieved with a CTAB concentration of 2×10&lt;sup&gt;-4&lt;/sup&gt; mol/L and an APAM dosage of 20 mg/L. When combining agents, the best results are observed when CTAB is added before APAM. By fixing the APAM dosage at 20 mg/L and varying the CTAB concentration, the highest sedimentation rate and lowest turbidity are obtained at a CTAB concentration of 1.5×10&lt;sup&gt;-4&lt;/sup&gt; mol/L. Mechanistic insights were obtained through aggregate imaging, area measurement, zeta potential testing, and contact angle testing. Cationic surfactants alter the surface properties of particles, reducing surface electronegativity and increasing hydrophobicity, which diminishes inter-particle repulsion and promotes aggregation, thereby reducing turbidity. Flocculants form larger flocs through adsorption and bridging, accelerating the sedimentation process. When flocculants and cationic surfactants are used together, the resulting flocs are more stable and larger, with an average floc area reaching 5017.6079 µm&lt;sup&gt;2&lt;/sup&gt;, indicating a significant reduction in fine particles within the solution.

Influence of cationic surfactants on two-phase air–liquid displacement in porous media

The displacement efficiency of leaching agent solution in orebody pores is the key factor affecting the leaching rate of rare earth ions. To improve the displacement efficiency, cationic surfactants were added to the solution as the invading phase fluid, and microfluidic visualization experiments were carried out. Based on the experimental results, the effects of cationic surfactants on air-liquid two-phase displacement and its mechanism were analyzed. The results show that cationic surfactants can change the capillary fingering to stable displacement mode. Moreover, the closed air clusters are significantly reduced, and the displacement efficiency is greatly improved, up to 96.75 %. In addition, displacement efficiency is negatively correlated with the porosity of the porous media. Cationic surfactants primarily affect the displacement by changing the interfacial properties of the solution. The research results provide theoretical guidance for the efficient mining of ionic rare earths.

Effect of surfactants on the luminescence, bonding, and catalytic properties of CaWO4 spheres

BackgroundThis work focuses on improving the luminescence and catalytic properties of CaWO4 spheres by manipulating their electron density distribution. The goal is to enhance their suitability for optoelectronic applications and to increase their efficiency in degrading the industrial dye methylene blue (MB). The study utilizes a co-precipitation technique and the addition of three surfactants to synthesize phase-pure CaWO4 with a tetragonal crystal structure. MethodsThe synthesis involved a co-precipitation technique with simultaneous addition of three surfactants. Extensive characterization employed various analytical and spectroscopic methods to assess structural, morphological, luminescent, and catalytic properties. Particularly, the use of cetyltrimethylammonium bromide (CTAB) surfactant induced intense green emission around 500 nm attributed to luminescent center WO42−. Solar irradiation evaluated catalytic performance, with CaWO4: CTAB degrading methylene blue remarkably in just 40 min under natural sunlight. Significant FindingsThe research yielded a CaWO4 material, particularly when assisted by the CTAB surfactant, exhibiting intense green luminescence, making it promising for optoelectronic applications. Furthermore, this material demonstrated remarkable catalytic performance in degrading methylene blue under solar irradiation, suggesting its potential in environmental remediation. The study also delved into electron density distribution by examining differences in bond lengths and mid-bond electron density within a single unit cell, shedding light on the material's underlying properties.

The role of nanoparticle–surfactant interactions in air-stabilized foams used for improving oil recovery

Foam flooding, an emerging tertiary oil recovery technique, demonstrates efficacy as a conformance control method in enhanced oil recovery. Conformance control mitigates injected displacement fluid channeling and bypassing, improving macroscopic sweep efficiency. Generated foamed films preferentially enter high permeability zones, diverting subsequent injection into unswept lower permeability regions. Nanoparticle-reinforced foams exhibit consistent bulk stability and effective residual oil mobilization. This work utilizes dynamic foam analysis to probe the synergistic effects of zinc oxide nanoparticles and anionic surfactant on foam generation and persistence. Bulk and local scale foam stability is evaluated under various potassium chloride concentrations. Optimal foam stability occurs near the critical micelle concentration of the surfactant at 2,500 ppm. Increasing electrolyte concentration within a fixed surfactant formulation decreases foam stability due to salt-induced micellar swelling. An optimized electrolyte and nanoparticles with a surfactant combination produce high-quality foam with increased bubble density per unit area. Micellar swelling by nanoparticle adsorption inhibits lamellae thinning and liquid drainage. Enhanced foam properties improve microscopic displacement efficiency and mobility control in foam-assisted oil recovery. Oil recovery is increased by approximately 22% compared to conventional waterflooding.

Effect of surfactants on the permeation rate and selectivity of polyamide composite membranes for organic solvent nanofiltration

Solvent-resistant membranes are pivotal in industrial separations. This study aims to develop thin-film composite polyamide (TFC-PA) membranes with enhanced organic solvent nanofiltration (OSN) capabilities. Polyallylamine hydrochloride (PAAH) was used as the aqueous amine and isophthaloyl chloride (IPC) as the crosslinker to form the polyamide active layer by interfacial polymerization (IP) on a polyacrylonitrile (PAN) support. The impact of using anionic sodium dodecyl sulfate (SDS) and cationic cetyltrimethylammonium bromide (CTAB) to act as phase transfer agents during IP was investigated to understand their potential for facilitating the transfer of PAAH to the organic phase for reaction with IPC. The SDS and CTAB were separately dissolved into the PAAH solutions before IP to evaluate their effects on membrane properties. Extensive characterization including SEM, EDX, AFM, Water Contact Angle, ATR-FTIR, and Solid (CP-MAS) 13C NMR revealed various chemical and structural features of the membrane. The membrane M2 (PAAH-IPC) (exhibited >98% rejection for various anionic and cationic dyes. The inclusion of SDS during interfacial polymerization led to a substantial 3-fold increase in methanol permeate flux from 31 L m−2 h−1 to 119 L m−2 h−1, at a pressure of 15 bar. Conversely, the addition of CTAB resulted in membranes with higher permeate flux but insufficient dye rejection. Moreover, after three weeks of static aging of the membranes no significant changes were detected in either permeability or solute rejection, substantiating the stability of membranes.