Surfactant Sodium Dodecylbenzenesulfonate Research Articles

High-Yield Preparation and Properties of Phenolic Resin-Based Carbon Microspheres.

This study aims to enhance the production efficiency of carbon microspheres (CS) and expand their potential applications. To this end, resorcinol-formaldehyde microspheres (RFS) were prepared in high yield through the modified Stöber method, utilizing resorcinol and formaldehyde as carbon sources, ammonia as a catalyst, and sodium dodecyl benzenesulfonate (SDBS) as a soft template. The resulting RFS were then carbonized to obtain high yield CS. This study examined the impact of key factors, namely, the concentration of resorcinol, ammonia, and the SDBS concentration, along with the temperature of carbonization, upon the properties of the resulting CS, which were observed with regard to microscopic morphology, average particle size, homogeneity, and yield. The findings demonstrated that the proclivity of RFS to agglomerate with one another at high carbon source concentrations was markedly diminished, while the yield of CS was notably enhanced through the introduction of the anionic surfactant SDBS. The particle size of RFS can be modified within the range 200-1000 nm by adjusting the resorcinol and ammonia concentration. The prepared RFS exhibited a regular spherical morphology and a smooth surface. Furthermore, the CS displayed a uniform spherical morphology following high-temperature carbonization, with no agglomeration or cross-linking observed between adjacent particles. It was observed that the yield of RFS reached a maximum of 93.2 g/L when the resorcinol concentration was 0.7 mol/L. Following carbonization at 800 °C, the yield of CS was found to be 41.9 g/L, with a diameter of 770 nm and good monodispersity.

Multi-scale evaluation of surfactant effects on asphalt desorption behavior from oil sand surfaces

This study created a hydrophobic oil sand model to investigate the impact of surfactants on the desorption behavior of asphalt from solid surface. Cationic surfactant cetyl trimethyl ammonium bromide (CTAB) and anionic surfactant sodium dodecyl benzene sulfonate (SDBS) were used to soak the model to observe the effect of surfactants on asphalt desorption. The effect of surfactant pretreatment on the wettability of the substrate was evaluated by measuring the contact angle of ultrapure water on the substrate and observing the morphological changes of the solid surface by atomic force microscopy. The results show that the contact angle of the model treated with SDBS decreases to 10° after 3 days, which significantly improves the wettability of the substrate surface and promotes the desorption of asphalt. However, CTAB has no obvious effect on asphalt desorption. The standard deviation of the gray value of the sand surface image is significantly reduced to 38.693 after the SDBS treatment, which can be seen by binarizing the image. This suggests that the asphalt and solution are evenly distributed and that there is hardly any discernible boundary. Nevertheless, neither of the two surfactants can improve the water-based extraction efficiency of oil sands after soaking treatment. The asphalt yield is less than 5% after 30 days of pretreatment with CTAB solution, while only 45% asphalt yield is obtained after 30 days of pretreatment with SDBS solution. Despite these variations, the quality of asphalt foam remains relatively the same. This may be related to the failure of surfactants to improve the surface wettability of hydrophobic sand. Therefore, the surface wettability of the sand is considered to be a key factor affecting the asphalt desorption and final yield. This study can provide a scientific basis for oil sand recovery to a certain extent.

Solvent-induced modulation of sensitivity and selectivity in the self-assembly of tetracationic cyclophanes with cholesterol sulphate, sodium dodecyl sulfate, and sodium dodecyl benzene sulfonate: Observations of significant shifts

Cyclophane CP-1 demonstrates markedly distinct sensitivities toward Cholesterol sulfate (CH-S), Sodium Dodecyl Sulfate (SDS), and Sodium Dodecyl Benzene Sulfonate (SDBS) when the solvent is shifted minimally from a 95 % to a 98 % HEPES-DMSO mixture. In a 98:2 HEPES-DMSO mixture, CP-1 engages in highly selective self-assembly with CH-S, which is characterized by aggregation-induced emission enhancement (AIEE) in contrast to other steroidal sulfates such as pregnenolone sulfate (PRG-S), dehydroisoandrosterone sulfate (DIAND-S), taurocholic acid (TACH-S), and the surfactants SDS and SDBS. This assembly results in an approximate 40-fold increase in fluorescence intensity with three equivalents of CH-S and allows for the detection of concentrations as low as 200 nM under physiological conditions. Dynamic light scattering (DLS) studies illustrate the aggregation of CP-1 and CH-S, with the zeta potential of each shifting from negative values to nearly zero in a 1:2 CP-1:CH-S mixture, indicating self-assembly. This aggregation behavior is reversible, as demonstrated by a corresponding decrease and then increase in fluorescence intensity with temperature variations from 25 °C to 70 °C and back to 25 °C. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) analyses show that CP-1 forms aggregates ranging from 100 to 180 nm, which increase to 150–250 nm upon interaction with CH-S. In a 95:5 HEPES-DMSO mixture, CP-1 exhibits a stronger AIEE response with SDS and SDBS compared to CH-S. Cyclophane CP-2, when dissolved in binary DMSO-water mixtures with water content exceeding 80 %, shows similar AIEE phenomena and undergoes selective fluorescence quenching with SDS and only a 50 % increase in fluorescence intensity with CH-S, irrespective of the HEPES concentration (95 % or 98 %).

Degradation of sodium dodecyl benzene sulfonate in aqueous solution by electron beam radiation and changes in surfactant micelle property

In this study, we investigated the degradation of surfactant sodium dodecyl benzene sulfonate (SDBS) in aqueous solution using electron beam radiation. The removal efficiency of SDBS approached nearly 100%, achieving a COD removal rate of 7–20% with an absorbed dose of 5.0 kGy. Upon irradiation, several notable changes in SDBS micelles were observed. The absolute value of zeta potential and the average diameter size decreased. SEM observations revealed that the clustered aggregates of SDBS micelles fragmented into irregular filamentous pieces. Moreover, the interfacial tension increased remarkably and approached the level of pure water at 2.5 kGy for SDBS in a pure water solution and 5.0 kGy for SDBS in a brine water solution. The foaming power disappeared for SDBS in pure water and decreased to 20 mm for SDBS in brine water at 10 kGy. The defoaming rate of SDBS solution increased incrementally from an initial range of 1–2 mm/min to 3.0–5.6 mm/min at 5.0 kGy. In summary, when SDBS is decomposed, new system is created with new properties. Electron beam radiation offers a clean and sustainable approach to degrade SDBS in wastewater.

Highly 002-Oriented Dendrite-Free Anode Achieved by Enhanced Interfacial Electrostatic Adsorption for Aqueous Zinc-Ion Batteries.

Rechargeable aqueous zinc-ion batteries (AZIBs) are gaining recognition as promising next-generation energy storage solution, due to their intrinsic safety and low cost. Nevertheless, the advancement of AZIBs is greatly limited by the abnormal growth of zinc dendrites during cycling. Electrolyte additives are effective at suppressing zinc dendrites, but there is currently no effective additive screening criterion. Herein, we propose employing the interfacial electrostatic adsorption strength of zinc ions for the initial screening of additives. Subsequently, dendrite-free plating is achieved by employing the anionic surfactant sodium dodecyl benzenesulfonate (SDBS) to enhance electrostatic adsorption. The cycled zinc anode exhibited a dense plating morphology and a high (002) orientation (I002/I101 = 22). The Zn||MnO2 full cell with SDBS exhibited a capacity retention of 85% after 1000 cycles at 1 A g-1. Furthermore, an instantaneous nucleation model and continuous nucleation model (CNM) are constructed to reveal the microscale plating/stripping dynamics under the scenarios of weak adsorption and strong adsorption. The CNM accurately explains the self-optimizing reconstruction of electrodes resulting from enhanced electrostatic adsorption. Our exploration was extended to other anionic surfactants (sodium dodecyl sulfate and disodium laureiminodipropionate), confirming the effectiveness of strong electrostatic adsorption in the screening of electrolyte additives.

Removal of sodium dodecyl benzene sulfonate using bagasse fly ash and surface functionalized modified fly ash from aqueous solutions

AbstractThis study explores the efficacy of a cost‐effective, functionalized adsorbent derived from bagasse fly ash (FA) for the removal of the surfactant sodium dodecylbenzene sulfonate (SDBS) from aqueous solutions. The raw bagasse FA underwent a modification process involving reflux with TiO2 in NaOH at 100°C for 24 h, resulting in a modified fly ash (MFA). Comparative analyses of the sorbents were conducted using scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X‐ray diffraction (pXRD), Brunauer–Emmett–Teller (BET) surface analysis, and Fourier‐transform infrared spectroscopy (FT‐IR). The surface area of the original FA was found to be 10.795 m2 g−1, which increased to 30.597 m2 g−1 postmodification. Similarly, the crystallinity of FA was initially 49.36% and enhanced to 79.70% after the modification process. The adsorption process of SDBS onto both FA and MFA were found to follow pseudo‐second‐order kinetics. Moreover, the Langmuir adsorption isotherm was the most fitting model, as evidenced by the R2 values at 298 K for SDBS‐FA (0.99) and SDBS‐MFA (0.99), both of which are remarkably close to unity. The dimensionless separation factor (RL) was determined to be less than one, indicating favorable adsorption. The maximum adsorption capacities predicted by the Langmuir model are 156.00 mg/g for FA and a notably higher 231.48 mg/g for MFA. Thermodynamic analysis revealed a positive change in enthalpy (ΔHo) for SDBS‐FA and SDBS‐MFA of 54.50 and 124.48 KJ mol−1, respectively, suggesting endothermic adsorption. Additionally, the Gibbs free energy (ΔGo) was negative for both SDBS‐FA and SDBS‐MFA, suggesting that the adsorption of SDBS is spontaneous.

Modulating Visible-Light Driven NIR Lanthanide Polymer Photocatalysis for Amplification Detection of Exosomal Proteins and Cancer Diagnosis.

Near-infrared (NIR) luminescent lanthanide materials hold great promise for bioanalysis, as they have anti-interference properties. The approach of efficient luminescence is sensitization through a reasonable chromophore to overcome the obstacle of the aqueous phase. The involvement of the surfactant motif is an innovative strategy to arrange the amphiphilic groups to be regularly distributed near the polymer to form a closed sensitized space. Herein, a lanthanide polymer (TCPP-PEI70K-FITC@Yb/SDBS) is designed in which the meso-tetra(4-carboxyphenyl)porphine (TCPP) ligand serves as both a sensitizer and photocatalytic switch. The surfactant sodium dodecyl benzenesulfonate (SDBS) wraps the photosensitive polymers to form a hydrophobic layer, which augments the light-harvesting ability and expedites its photocatalysis. TCPP-PEI70K-FITC@Yb/SDBS is subsequently applied as an amplified photocatalysis toolbox for universally regulating the generation of reactive oxygen species (ROS). Boosting 3,3',5,5'-tetramethylbenzidine (TMB) oxidation to produce blue products, a dual-mode biosensor is fabricated for improving the diagnosis of programmed death ligand-1-positive (PDL1) cancer exosomes. Exosomes were captured by Fe3O4 modified by the PDL1 aptamer, enabling replacement of alkaline phosphatase (ALP)-labeled multiple hybridized chains; then, the isolated ALP triggered a hydrolysis reaction to block the generation of oxTMB. Detection sensitivity improves by 1 order of magnitude through SDBS modulation, down to 104 particles/mL. The sensor performed well clinically in distinguishing cancer patients from healthy individuals, expanding physiological applications of near-infrared lanthanide luminescence.

Formation and survival of clay-mediated protocell membranes composed of single-chain amphiphiles in aqueous solutions

Protocell compartments composed of simple amphiphilic molecules could have survived on the clay mineral surfaces which can serve well as plausible sites for prebiotic chemistry on the early Earth. Herein we chose four common single-chain amphiphiles (SCAs), including the anionic surfactant sodium dodecyl sulfate (SDS) and sodium dodecylbenzenesulfonate (SDBS), the cationic surfactant dodecyltrimethylammonium bromide (DTAB) and the zwitterionic lauryl sulfobetaine (LSB)), as model constituents of early membranes to establish a tentative model for protocell compartment. Positively charged Mg2Al-/Mg2Fe-layered double hydroxides (LDHs) and FeS2 are viewed as models of clay minerals. We demonstrate by comprehensively experimental study that unconventional vesicles can be easily promoted in a SCA aqueous micellar solution in the presence of model particles. Morphology evolutions are traced by collecting samples from mixtures of LDHs and SCA aqueous solutions and then recording at different incubation times via negative-staining or cryo-transmission electron microscopy (NS-TEM or cryo-TEM) and dynamic light scattering (DLS). Additionally, the stability of SCA bilayer membranes under possible prebiotic environment are tentatively studied. This work not only offers a robust yet versatile approach for the fabrication of novel vesicles but also provides new insights into the origin of cellular life.

Role of anionic surfactant addition in improving thermoelectric properties of PEDOT:PSS free-standing films

Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) has recently gained interest as a potential candidate for small-scale thermoelectric conversion because of the facile doping, solution processability, and flexibility. However, the practical applications of PEDOT:PSS are limited by its comparatively low figure of merit (ZT) compared with inorganic thermoelectric materials. Herein, to further improve the thermoelectric properties of PEDOT:PSS, we investigated the role of the addition of surfactants, sodium dodecyl sulfate, sodium dodecyl benzenesulfonate (SDBS) or Triton X-100, to the PEDOT:PSS free-standing films on their thermoelectric properties. We showed that the addition of the surfactant improved the film crystallinity, significantly improving the electrical conductivity. The highest conductivity was obtained for anionic surfactant SDBS at a 0.94 wt% concentration. Moreover, the inclusion of the surfactant reduced the thermal conductivity while maintaining a relatively constant Seebeck coefficient, consequently improving the ZT value. Furthermore, a flexible thermoelectric device crafted from the as-fabricated PEDOT:PSS/SDBS sheets was developed to explore the potential applications of wearable electronics using low-grade thermal energy. Overall, we indicate the significance of surfactants in enhancing the thermoelectric properties of free-standing PEDOT:PSS films in this study.

Effects of sodium dodecylbenzene sulfonate (SDBS), active principle of detergents, on the liver and kidney of zebrafish (Danio rerio)

ABSTRACT Sodium dodecylbenzene sulfonate (SDBS), a predominant component in detergents, requires an evaluation of its toxicological potential due to its hazardous environmental levels. Therefore, we evaluated the toxicological effects of SDBS on the liver and kidney of male D. rerio. Therefore, we evaluated the toxicological effects of SDBS on the liver and kidney of male D. rerio. The fish were divided into three groups: 0.0 (control), 0.25, and 0.5 mg/L of SDBS with exposure for up to 96 hours. After exposure, histopathological, histochemical (hepatic glycogen content), and biochemical analyses (SOD and CAT enzyme analysis) were performed on both organs. The results showed significant histopathological effects, such as circulatory disturbances and progressive and regressive alterations, leading to an altered histopathological alteration index. SOD and CAT enzymes exhibited prominent changes. Thus, it became clear that the surfactant SDBS can cause serious hepatic and renal problems in D. rerio fish, even with short-term exposure, necessitating more stringent control and regulation in the disposal of this surfactant.

Experimental Study on the Hydraulic Performance of the Horizontal Main Drain of Building Drainage Systems Affected by Surfactants Sodium Dodecyl Benzene Sulfonate and Alkyl Ethoxylate-9

Experimental Study on the Hydraulic Performance of the Horizontal Main Drain of Building Drainage Systems Affected by Surfactants Sodium Dodecyl Benzene Sulfonate and Alkyl Ethoxylate-9

Tuning the mechanical and thermoelectric properties of self‐standing stretchable PEDOT:PSS/SDBS films

AbstractPoly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) has recently attracted significant attention as a potential candidate for small‐scale thermoelectric conversion because of its ease of doping, and solution processability. This study addressed the fabrication of self‐standing PEDOT:PSS films modified with sodium dodecylbenzene sulfonate (SDBS) surfactant, presuming different annealing temperatures. According to the investigation, optimizing the annealing temperature improves crystal quality and increases the efficiency of PEDOT:PSS films. The resulting PEDOT:PSS films showed the highest electrical conductivity of about 623.68 Scm−1 and maximum power factor of 25.87 μWm−1 K−2. In addition to confirming thermoelectric properties; SDBS surfactants are being investigated to plasticize PEDOT:PSS films at different concentrations and annealing temperatures. With an optimization in annealing temperature, the elongation at break value similarly improves; and the highest elongation at break was observed at 0.94 wt% SDBS concentration, reaching 32%. To completely understand the underlying reasons for this dependence, higher‐order structures and electronic states of polymer films have been examined using electronic reflectance spectroscopy and X‐ray diffraction analysis. Overall, the outcomes of this work show how important surfactants and their annealing temperature are for improving the mechanical and thermoelectric characteristics of self‐standing PEDOT:PSS films.

Comparative study of nanoemulsion and micelle formed by surfactants containing benzene ring for spontaneous imbibition displacement

Nanoemulsion has a wide range of applications in oilfield chemistry due to its unique nanoscale size, excellent kinetic stability and high specific surface area. In this paper, a novel nanoemulsion oil flooding system was prepared using anionic surfactant sodium dodecyl benzene sulfonate (SDBS), the nonionic surfactant alkylphenol ethoxylates (OP-10), kerosene, n-butanol and deionized water. The particle size, Zeta potential, interfacial tension (IFT) and wettability properties were evaluated in the laboratory. The displacement performance of nanoemulsion was evaluated by the spontaneous imbibition experiment. Meanwhile, it compared with the same concentration of SDBS + OP-10 + n-butanol (SOB) system. The results showed that the particle size of the nanoemulsion was 70 ∼ 100 nm. When the concentration of nanoemulsion was 0.10 %, the oil–water IFT could reach 0.091 mN/m. The spontaneous imbibition oil recovery of the nanoemulsion (0.10 wt%) could reach 33.20 %, which was 23.02 % higher than that of SOB system. We also research the spontaneous imbibition displacement mechanism of nanoemulsion and micelle in low-permeability reservoirs. This paper will help to select the best oil displacement agent for the design of enhanced oil recovery (EOR) projects and promote the application of oil displacement agent in oilfield.

An artificial liquid–liquid phase separation-driven silk fibroin-based adhesive for rapid hemostasis and wound sealing

The powerful adhesion systems of marine organisms have inspired the development of artificial protein-based bioadhesives. However, achieving robust wet adhesion using artificial bioadhesives remains technically challenging because the key element of liquid–liquid phase separation (LLPS)-driven complex coacervation in natural adhesion systems is often ignored. In this study, mimicking the complex coacervation phenomenon of marine organisms, an artificial protein-based adhesive hydrogel (SFG hydrogel) was developed by adopting the LLPS-mediated coacervation of the natural protein silk fibroin (SF) and the anionic surfactant sodium dodecylbenzene sulfonate (SDBS). The assembled SF/SDBS complex coacervate enabled precise spatial positioning and easy self-adjustable deposition on irregular substrate surfaces, allowing for tight contact. Spontaneous liquid-to-solid maturation promoted the phase transition of the SF/SDBS complex coacervate to form the SFG hydrogel in situ, enhancing its bulk cohesiveness and interfacial adhesion. The formed SFG hydrogel exhibited intrinsic advantages as a new type of artificial protein-based adhesive, including good biocompatibility, robust wet adhesion, rapid blood-clotting capacity, and easy operation. In vitro and in vivo experiments demonstrated that the SFG hydrogel not only achieved instant and effective hemostatic sealing of tissue injuries but also promoted wound healing and tissue regeneration, thus advancing its clinical applications. Statement of significanceMarine mussels utilize the liquid–liquid phase separation (LLPS) strategy to induce the supramolecular assembly of mussel foot proteins, which plays a critical role in strong underwater adhesion of mussel foot proteins. Herein, an artificial protein-based adhesive hydrogel (named SFG hydrogel) was reported by adopting the LLPS-mediated coacervation of natural protein silk fibroin (SF) and anionic surfactant sodium dodecylbenzene sulfonate (SDBS). The assembled SFG hydrogel enabled the precise spatial positioning and easy self-adjustable deposition on substrate surfaces with irregularities, allowing tight interfacial adhesion and cohesiveness. The SFG hydrogel not only achieved instant and effective hemostatic sealing of tissue injuries but also promoted wound healing and tissue regeneration, exhibiting intrinsic advantages as a new type of artificial protein-based bioadhesives.

Green Surfactant Assisted-Solidified Floating Organic Drop Micro-Extraction (SA-SFODME) for the Preconcentration of Trace Lead with Determination by Flame Atomic Absorption Spectrometry (FAAS)

Determination of trace lead from environmental samples was carried out by solidified floating organic drop microextraction for preconcentration before analysis by flame atomic absorption spectrometry. The determination of lead from environmental samples, even at trace levels, was possible with an ordinary flame atomic absorption spectrometer (FAAS). The lead formed a hydrophobic complex with the anionic surfactant sodium dodecyl benzene sulfonate (SDBS), and this hydrophobic complex was extracted into the 1-dodecanol drop. Parameters affecting analytical performance have been studied. The optimum pH value was 3.5. The optimum sample volume, SDBS concentration, and extraction solvent volume were 75 mL, 50 mM in dodecanol, and 75 µL, respectively. The optimum extraction time was determined as 30 min, the optimum extraction temperature was 45 °C, the optimum mixing speed was 650 rpm and the ideal extraction phase volume was 0.50 mL. Methanol has been shown to be effective when used as a diluent. Using the optimum conditions, the enhancement factor was 106, and the limit of detection (3s) and precision were 3.3 ng/mL and 2.3% (n = 9,15 ng/mL), respectively. The limit of quantification (LOQ) (10s) was 10 ng/mL and the linear working range was 15-100 ng/mL. The accuracy was evaluated by certified reference material analysis. The optimized method was applied to the determination of Pb(II) from environmental water samples. This method follows the principles of green analytical chemistry.

Stretchable and Flexible Painted Thermoelectric Generators on Japanese Paper Using Inks Dispersed with P- and N-Type Single-Walled Carbon Nanotubes.

As power sources for Internet-of-Things sensors, thermoelectric generators must exhibit compactness, flexibility, and low manufacturing costs. Stretchable and flexible painted thermoelectric generators were fabricated on Japanese paper using inks with dispersed p- and n-type single-walled carbon nanotubes (SWCNTs). The p- and n-type SWCNT inks were dispersed using the anionic surfactant of sodium dodecylbenzene sulfonate and the cationic surfactant of dimethyldioctadecylammonium chloride, respectively. The bundle diameters of the p- and n-type SWCNT layers painted on Japanese paper differed significantly; however, the crystallinities of both types of layers were almost the same. The thermoelectric properties of both types of layers exhibited mostly the same values at 30 °C; however, the properties, particularly the electrical conductivity, of the n-type layer increased linearly, and of the p-type layer decreased as the temperature increased. The p- and n-type SWCNT inks were used to paint striped patterns on Japanese paper. By folding at the boundaries of the patterns, painted generators can shrink and expand, even on curved surfaces. The painted generator (length: 145 mm, height: 13 mm) exhibited an output voltage of 10.4 mV and a maximum power of 0.21 μW with a temperature difference of 64 K at 120 °C on the hot side.

Sol–gel-stabilized CO2 foam for enhanced in-situ carbonation in foamed fly ash backfill materials

AbstractA novel highly stable aqueous foam was synthesized using CO2, sodium silicate (SS) and anionic surfactant of sodium dodecylbenzene sulfonate. The influence of CO2 foam on the mechanical properties and its underlying mechanisms of foamed backfill material was investigated. The experimental results revealed that the addition of CO2 and SS effectively reduced the drainage of the foam while strengthening the liquid film of the Plateau borders, which stabilizes the foam. The excellent stability is attributable to the gel network developed after SS exposed to CO2, that adhere to the foam surface. Furthermore, due to the interaction between encapsulated CO2 and hydration products, micro CaCO3 formed and filled the pore wall; thus, precast foam forms robust pore structures in the hardened foamed backfill.

Theoretical study on the influence of three different surfactants on the binding of laccase with bisphenol A

Laccase catalyzes the formation of phenoxyl radicals as an intermediate in Bisphenol A (BPA) degradation, and certain surfactants can affect the effectiveness of laccase in removing BPA from various effluents, yet the specific molecular details remain unclear. In this study, based on laccase and BPA complex, three surfactants, cetyltrimethylammonium bromide (CTAB), sodium dodecylbenzene sulfonate (SDBS), and TritonX-100 (TX-100), were introduced to construct four systems. We applied MD simulation along with MM-PBSA method to investigate the effects of different surfactants on the binding of laccase with BPA. During the MD simulations, these three surfactants enveloped the enzyme surface to varying degrees, causing the solvent to separate from parts of the laccase surface. The addition of CTAB and SDBS suppressed BPA degradation mainly by influencing the polar solvation free energy and van der Waals (vdW) interactions between laccase and BPA. In contrast, TX-100 promoted the degradation of BPA by reducing polar solvation free energy. This explains why in the laccase-BPA complex system the addition of a certain concentration of TX-100 resulted in a higher degradation rate compared to CTAB or SDBS. Our work clarifies the molecular mechanisms of the interaction between laccase and BPA under the influence of CTAB, SDBS, and TX-100 surfactants, and provides some guidance for laccase degradation of BPA.

Adsorption of single and mixed surfactants consisting of cocoamidopropyl betaine (CAPB) and sodium dodecyl benzene sulfonate (SDBS) onto zinc surface

Abstract Aqueous solutions of surfactants exhibit remarkable differences in their adsorption properties on metal surfaces. This study evaluates the adsorption of surfactant mixtures on zinc metal surfaces. The adsorption of single surfactants cocamidopropyl betaine (CAPB) and sodium dodecyl benzenesulfonate (SDBS) and their mixtures from aqueous solution at mole fractions of 0.00, 0.25, 0.50, 0.75 and 1.00 on zinc powder at 25 °C was studied. The surface tension of the single and CAPB/SDBS surfactant mixtures was measured in the presence and absence of 2 % zinc powder to determine the adsorption isotherms. The depletion method was employed to carry out the adsorption investigation. The amount of the surfactant adsorbed was also calculated from the shaded area between the surface tension versus concentration curves of these surfactants in the presence and absence of 2 % zinc powder. The highest adsorbed amounts were found to increase with the SDBS content. Furthermore, scanning electron microscope (SEM) images of zinc sheets in solutions containing single or mixed CAPB/SDBS surfactants were taken in the presence and absence of 0.05 M HCl. The micrographs indicated that the CAPB-SDBS surfactant layers formed by precipitation can protect zinc metal from acid corrosion.

Comparative Analysis of Hydrogel Adsorption/Desorption with and without Surfactants.

In this particular study, a hydrogel known as SAP-1 was synthesized through the grafting of acrylic acid-co-acrylamide onto pullulan, resulting in the creation of Pul-g-Poly (acrylic acid-co-acrylamide). Additionally, a sponge hydrogel named SAP-2 was prepared by incorporating the surfactant sodium dodecyl benzene sulfonate (SDBS) into the hydrogel through free radical solution polymerization. To gain further insight into the composition and properties of the hydrogels, various techniques, such as Fourier transform infrared spectroscopy, hydrogen nuclear magnetic resonance (1H NMR), atomic absorption spectroscopy, and field emission scanning electron microscopy (FE-SEM), were employed. Conversely, the absorption kinetics and the equilibrium capacities of the prepared hydrogels were investigated and analyzed. The outcomes of the investigation indicated that each of the synthesized hydrogels exhibited considerable efficacy as adsorbents for cadmium (II), copper (II), and nickel (II) ions. In particular, SAP-2 gel displayed a remarkable cadmium (II) ion absorption ability, with a rate of 190.72 mg/g. Following closely, SAP-1 gel demonstrated the ability to absorb cadmium (II) ions at a rate of 146.9 mg/g and copper (II) ions at a rate of 154 mg/g. Notably, SAP-2 hydrogel demonstrated the ability to repeat the adsorption-desorption cycles three times for cadmium (II) ions, resulting in absorption capacities of 190.72 mg/g, 100.43 mg/g, and 19.64 mg/g for the first, second, and third cycles, respectively. Thus, based on the abovementioned results, it can be concluded that all the synthesized hydrogels possess promising potential as suitable candidates for the adsorption and desorption of cadmium (II), copper (II), and nickel (II) ions.