Mixtures Of Anionic Surfactants Research Articles

Analysis of a Liquid Handwashing Detergent Product and Identification with an Infrared Absorption Spectrum and a Reflectance Graph

Detergent products are by their chemical composition complex materials, commonly classified by their origin as a mixture of anionic and nonionic surfactants, or as of single surfactants. One of the most prominent applications of detergents is for domestic cleaning [1] as for the detergents currently examined.

Phase Diagram Study of Catanionic Surfactants Using Dissipative Particle Dynamics.

Dissipative particle dynamics (DPD) simulations has been performed to study the phase transition of a mixture of cationic and anionic surfactants in an aqueous solution as a function of the total concentration in water and the relative ratio of surfactants. The impact of the relative difference between the tail lengths of the cationic and anionic surfactants on the phase diagram has been simulated by tuning the number of DPD beads in the simulation model. This research also discusses the impact of the frequently used values of the parameters associated with the harmonic bonds among the bonded DPD beads on the obtained self-assemblies. We find remarkable differences in the resultant self-assemblies based on different choices of harmonic bond parameters. The performed simulations show an enhanced spectrum of self-assemblies with augmented tail lengths and disparate harmonic bond parameters. The obtained self-assemblies are quite unique and can potentially be used in the future for various applications. We also compare the simulation results of the vesicle structures obtained by modeling the electrostatic interaction in the simulation among the charged beads by explicitly introducing charges with a long-range interaction with those obtained by tuning the implicit electrostatic interaction without the long-range interaction. The effects of the chain length of the model and the harmonic bond parameters on the internal density of DPD beads and stress profiles within the vesicles are examined closely. These results are a significant contribution to understanding the stability of the phases and tailoring of the desired vesicles.

Potential of some surfactant mixtures for production of eco-friendly detergents used in seawater

Mixtures of surfactants are the most important ingredients which are combined to improve the application properties of liquid detergent. In this study, we evaluated the biological, chemical, and physical properties of various mixtures of anionic, non-ionic, and amphoteric surfactants. The results showed that the SAM5 formulation, consisting of SLES/AOS/CAPB and APG (70:15:5:10, w/w/w/w), was the highest cleaning effective in removing petroleum oily residues in seawater (94.78%). Among six formulations, SAM5 presented the best performance with highly foaming volume (335 mL), good foam stability (95.52%), and low surface tension (24.17 mN/m), readily biodegradable, and corrosion resistance ability. SAM5 formulation is used for further research and application in manufacturing a new liquid detergent used in seawater to remove petrolium oily residues.

The high-concentration stable phase: The breakthrough of catanionic surfactant aqueous system

Precipitates occur readily in the aqueous mixture of cationic and anionic surfactants. We report that the precipitates formed in the catanionic surfactant systems at charge ratios deviated from 1:1 can be solubilized by simply increasing the total surfactant concentrations. At higher concentrations, there are vesicles in the supernatant, which will sequester the monomer surfactant in equilibrium with the precipitates. This shifts precipitation-solvation equilibrium continuously. As a result, the precipitates vanish when all the surfactants in the precipitates are taken into the vesicles. In this way, a high-concentration stable phase (HCSP) can be formed in the precipitated surfactant systems, which can be generalized to all catanionic surfactant systems. We envision the concentration-triggered HCSP is very promising in guiding the large-scale application of catanionic surfactants.

The Effect of Na-Based Salts on Critical Aggregation Concentration of Aqueous Peg-Sds Mixtures

Critical aggregation concentration (CAC) is a well-known parameter used to study the interactions between constituents in an aqueous mixture containing surfactant molecules. In this study, we have studied the effect of Na-based salts on CAC of aqueous binary mixture of neutral polymer, polyethylene glycol (PEG) and anionic surfactant, sodium dodecyl sulfate (SDS) using viscometric method. To estimate CAC, we have applied Jiang model to the measured viscosity data. From the estimated results, we observe that the value of CAC decreases with the increase of salt molecules in the mixtures. This behavior confirms that the presence of salt molecules favors the binding of SDS molecule to the PEG chain. Bangladesh Journal of Physics, 27(2), 39-48, December 2020

Investigation of polymer−surfactant complexes by both micellar solubilization and pre-column derivatization capillary electrophoresis

“Pseudo-polyanions” are formed in some mixtures of nonionic water-soluble polymers and anionic surfactants with ultraviolet (UV) absorption signals, which is verified by capillary electrophoresis (CE) equipped with an UV detector. However, it is still unclear whether two typical mixtures of PEG (polyethylene glycol)−LDS (lithium dodecylsulfate) and PEG−SDS (sodium dodecylsulfate) are pseudo-polyanions or not due to lack of necessary UV absorption. Therefore, with the help of UV probes or UV labeling reagents, micellar solubilization CE and pre-column derivatization CE are implemented to make the mixtures detectable or “visible” by a UV detector. Experimental results show that both PEG–LDS and PEG–SDS complexes are pseudo-polyanions verified by the above strategies. Combined with previous works, most mixtures of nonionic water-soluble polymers and anionic surfactants can form unique pseudo-polyanions by dint of ion bridge no matter whether with or without UV absorption. What’s more, the bridging-to-diffusion ion ratio and the charge-to-size ratio of pseudo-polyanions are dominated by the bridging ions, and the smaller the hydrated ionic radius (H+ < K+ < Na+ < Li+) is, the stronger the polyanion nature is.

Determination of Equilibrium Adsorbed Morphologies of Surfactants at Metal-Water Interfaces Using a Modified Umbrella Sampling-Based Methodology.

Surfactants adsorb to metal-water interfaces in various morphologies, including self-assembled monolayers (SAMs), cylindrical and spherical micelles, or hemimicelles. Current molecular simulation methods are unable to efficiently sample the formation of these morphologies because of the large diffusive/energetic barriers. We introduce a modified umbrella sampling-based methodology that allows sampling of these morphologies from any initial configuration and provides free energy differences between them. Using this methodology, we have studied adsorption behavior of cationic [quaternary ammonium (quat) of 4 and 12 carbon long alkyl tails], uncharged [decanethiol], and anionic [phosphate monoester] surfactants and their mixtures at a gold-water interface. We find that while Coulombic repulsion between the charged head groups of quat-4 limits their adsorption to a sparse layer, stronger hydrophobic interactions between the alkyl tails of quat-12 promote adsorption resulting in a morphology with adsorbed hemispherical micelles sitting atop a monolayer. Decanethiol molecules adsorb in a densely packed bilayer with the molecules standing-up on the surface in the first layer and lying parallel to the surface in the second layer. Cationic and anionic surfactant mixtures display a synergistic adsorption behavior. These results elucidate the role of molecular characteristics in dictating the nature of adsorbed morphologies of surfactants at metal-water interfaces.

Activation energy, spatial confinement, and mean first passage and escape times of a tracer in a wormlike micellar fluid: an effective potential approach

Wormlike micelles are long semiflexible cylindrical polymer structures formed by amphiphiles. In solution, these linear micelles percolate in multiconected entangled networks, where cross-links can break and recombine dynamically. Technological applications of wormlike micellar fluids include tunable encapsulation/delivery of molecules or colloids in biomedicine, oil industry, and/or cleaning processes. In this work, we propose that the experimental activation energy, the spatial confinement, and the mean first passage and escape times of a spherical tracer immersed in wormlike micellar network, in which caging effects are observed, can be estimated from economic Brownian dynamics simulations of a single particle interacting with an effective one-dimensional cosine-like potential of amplitude U 0 and periodicity L. The proposed one-fitting parameter method has been used to characterize the long-time dynamics of wormlike micellar solutions formed by the self-assembly of a mixture of zwitterionic and anionic surfactants at several temperatures and different concentrations of surfactant and brine. The amplitude U 0 has displayed a good agreement regarding the corresponding experimental activation energy at different temperatures. The periodicity L has shown to be an upper bound of the mesh size ξ and of the same order of magnitude regarding the entanglement length l e, obtained from rheology and microrheology experiments. The escape time of the tracer in the effective potential τ escape and the time t*, at which a change of curvature in the mean square displacement occurs, are upper and lower limits, respectively, of the experimental relaxation time. Our method is simple and fast, and we foresee that it should be applicable to model the long-time behaviour of tracers in other polymer systems, in which caging effects are present.

Experimental Study on Application Performance of Foamed Concrete Prepared Based on a New Composite Foaming Agent

The performance of foaming agent plays a key role in the forming quality of foamed concrete. In order to overcome the limitation of single composition of traditional foaming agent, this paper adopts the research method of multicomponent composite combined with the foaming theory and preparation technology of foaming agent, a new protein composite foaming agent was prepared using a mixture of anionic surfactant (SCA), nonionic surfactant (APG), and foam stabilizer (AR), and then, the effects of different surfactant mass ratios and foam stabilizer concentrations on the properties of composite foaming agent were studied by a series of tests. The results show that the optimal mass ratio of surfactants is mAPG: mSCA = 2 : 1, and the optimal concentration of foam stabilizer is 0.5 g/L, which verified that the self-made composite foaming agent system in this paper has the advantages of strong foaming ability, excellent foam stability, and low cost. In addition, foamed concrete was prepared on the basis of the optimized composite foaming agent system, and the influence rules of different foaming agent solution volumes, water-cement ratios, and diatomite dosages on the performance of foamed concrete were revealed through laboratory tests and SEM images. At the same time, the optimal ratio of each component required for the preparation of high-quality foamed concrete was further obtained by using the response surface analysis of compressive strength. The research results provide an important reference for the preparation of high-performance foamed concrete and corresponding foaming agent, which is beneficial for solving the disadvantages of poor foam stability in the existing foaming agents and improving the application level of foamed concrete in engineering construction.

Strong synergistic interactions in zwitterionic–anionic surfactant mixtures at the air–water interface and in micelles: The role of steric and electrostatic interactions

Hypothesis: The milder interaction with biosystems makes the zwitterionic surfactants an important class of surfactants, and they are widely used in biological applications and in personal care formulations. An important aspect of those applications is their strong synergistic interaction with anionic surfactants. It is anticipated that the strong interaction will significantly affect the adsorption and self-assembly properties.Experiments: Surface tension, ST, neutron reflectivity, NR, and small angle neutron scattering, SANS, have been used here to explore the synergistic mixing in micelles and at the air–water interface for the zwitterionic surfactant, dodecyldimethylammonium propanesulfonate, C12SB, and the anionic surfactants, alkyl ester sulfonate, AES, in the absence and presence of electrolyte, 0.1 M NaCl.Findings: At the air–water interface the asymmetry of composition in the strong synergistic interaction and the changes with added electrolyte and anionic surfactant structure reflect the relative contributions of the electrostatic and steric interactions to the excess free energy of mixing. In the mixed micelles the synergy is less pronounced and indicates less severe packing constraints. The micelle structure is predominantly globular to elongated, and shows a pronounced micellar growth with composition which depends strongly upon the nature of the anionic surfactant and the addition of electrolyte.

The effect of aluminosilicate in anionic–nonionic surfactant mixture on wetness and interfacial tension in its application for enhanced oil recovery

In particular, this study aims to investigate the effect of aluminosilicate nanoparticle in the mixture of anionic (Sulfonated Alkyl Ester) and nonionic (Fatty Ester Oleate) surfactants on the interfacial tension and wettability related to EOR processes. Various experiments were conducted such as measuring interfacial tension between oil and brine using spinning drop tensiometer, measuring contact angle between surfactant-NPs-brine solution and Buff Berea core using optical tensiometer, conducting spontaneous imbibition, and core flooding tests.It is observed that the more anionic surfactant in the mixture the more significant aluminosilicate reduces contact angle and increases interfacial tension (IFT), which promotes contradicting effect on oil recovery. In this study, the IFT prevails and eventually reduces ultimate oil recovery. At spontaneous imbibition tests the ultimate oil recovery is decreased from 58% to 47% and from 63% to 46% for SAE-01A and SAE-01B, respectively. The ultimate oil recovery is reduced from 54% to 35% and from 50% to 39% at core flooding tests (Figure 16) for SAE-01A and SAE-01B, respectively. The aluminosilicate nanoparticle contributes positively as the ratio of SAE and FEO becomes smaller. At surfactant formulation ratio of 1:2 (SAE-01C), the IFT is decreased slightly from 4.36 x 10−3 mN/m to 2.36 x 10−3 mN/m and contact angle is also slightly reduced from 41.9° to 40.3° by adding 250 ppm NPs. The results show that ultimate oil recovery is increased 52% to 61% and from 47% to 49% at spontaneous imbibition tests and core flooding tests, respectively.

Micellar enhanced flocculation for the effective removal of reactive yellow 160 from synthetic textile effluent

This work provides insight into the surfactant-based removal of reactive yellow 160 (RY-160) present in the aqueous medium. Micellar enhanced flocculation technique was applied and optimized for the said purpose. The mixture of anionic surfactants, obtained from a bio-degradable source (base soap), has been found to have great potential to solubilize dye molecules. The polyvalent salts are able to flocculate the micelles and help in their subsequent removal. The removal of dye was analyzed by the use of a UV/Visible spectrophotometer. Different factors such as the effect of change in concentration, pH, temperature, contact time, and electrolyte were studied to evaluate the adsorption characteristics and removal efficiency of the process. The data obtained was further used to study the mechanism of adsorption with the help of various models e.g., Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich (D–R). The kinetic parameters were also calculated by employing pseudo-1st and pseudo-2nd order kinetic models. Furthermore, thermodynamic calculations were performed to determine the change in Gibb’s free energy (ΔGo), enthalpy (ΔHo), and entropy (ΔSo). The results make it evident that the micellar flocculation-based adsorptive removal is an excellent and sustainable approach for the treatment of wastewater.

Simultaneous adsorption of anionic alkyl sulfate surfactants onto alpha alumina particles: Experimental consideration and modeling

Simultaneous adsorption of four anionic alkyl sulfate (AS) surfactants, including sodium octyl sulfate, sodium decyl sulfate, sodium dodecyl sulfate and sodium tetradecyl sulfate named as C8, C10, C12 and C14, onto alpha alumina (α-Al2O3) particles were systematically investigated. Concentrations of all mixtures of anionic AS surfactants in aqueous solution were quantified by capillary electrophoresis coupled with contactless conductivity detection (CE-C4D). Adsorption isotherms of the four anionic AS surfactant homologs increased with either the decrease of pH from 6.0 to 4.0 due to enhancement of electrostatic attractions between the positively charged α-Al2O3 surface and the anionic AS surfactants or the increase of carbon chain length due to enhanced hydrophobic interactions. At different salt concentrations, a common intersection point (CIP) obtained for adsorption isotherms demonstrated that the contributions of electrostatic and hydrophobic interactions were reversed. The ionic strength effect on anionic AS surfactant adsorption isotherms onto α-Al2O3 particles was thoroughly studied. Simultaneous adsorption of the four AS surfactants onto the α-Al2O3was controlled by both electrostatic and hydrophobic interactions that were in accordance with Langmuir and two-step models.

Enzyme-Responsive Aqueous Two-Phase Systems in a Cationic-Anionic Surfactant Mixture.

Enzyme-instructed self-assembly is an increasingly attractive topic owing to its broad applications in biomaterials and biomedicine. In this work, we report an approach to construct enzyme-responsive aqueous surfactant two-phase (ASTP) systems serving as enzyme substrates by using a cationic surfactant (myristoylcholine chloride) and a series of anionic surfactants. Driven by the hydrophobic interaction and electrostatic attraction, self-assemblies of cationic-anionic surfactant mixtures result in biphasic systems containing condensed lamellar structures and coexisting dilute solutions, which turn into homogeneous aqueous phases in the presence of hydrolase (cholinesterase). The enzyme-sensitive ASTP systems reported in this work highlight potential applications in the active control of biomolecular enrichment/release and visual detection of cholinesterase.

Micellar flocculation for the treatment of synthetic dyestuff effluent: Kinetic, thermodynamic and mechanistic insights

This research work is an attempt to evaluate the role of micellar flocculation (MF) for the treatment of dye-contaminated water. Solubilization of dye by organized assemblies of anionic surfactants and its subsequent complexation with the metal cations during flocculation has been found as the active phenomena in this treatment methodology. Base soap (BS) being a mixture of anionic surfactants along with the salt of the divalent cation (Ca2+) was employed to capture and separate the reactive dye, reactive red 195 (RR-195), in the form of flocs at optimized concentrations of soap, dye, and flocculant. The effect of contact time, temperature, pH, and electrolyte has also been investigated to figure out the optimum conditions necessary to perform this adsorptive removal. The surface characteristics of adsorbent and favorability of adsorption were evaluated with the help of different isotherm models i.e., Langmuir, Freundlich, Dubinin–Radushkevich, and Temkin. Furthermore, kinetic and thermodynamic calculations were performed for a better understanding of the nature of the said removal. Herein, the results reveal that this removal process is spontaneous, favorable, and exothermic. The excellent removal of RR-195 (≈99%) through micellar flocculation suggests that it’s an economical, sustainable, and efficient approach for the treatment of industrial effluent containing dyes.

Rate enhancement of ‘in water’ organic transformation by anionic‐nonionic mixed micelle

AbstractMicellar medium has already promising uses in organic transformations. In the present experiment, mixture of anionic and neutral surfactants (SDS and TX‐100 respectively) has been discovered as a good reaction medium for the organic transformations. The kinetics of propanal oxidation by Cr(VI) has been studied in mixed micellar medium spectrophotometrically maintaining pseudo first order reaction condition at 30 °C. The kinetics of the same reactions promoted by three hetero‐aromatic bases (Phen, PA and Bpy) have already been studied in single as well as mixed micellar medium. The valid spectroscopic evidence of formation of the product and mixed micelle formation have been provided with necessary mechanistic pathways.

Mixtures of cationic guar gum and anionic surfactants as stabilizers of zirconia suspensions

Mixtures of cationic guar gum (CGG) with some anionic surfactants from different chemical groups (hydrocarbon, fluorinated and silicone surfactants) were used as stabilizers of zirconia suspensions. Stabilization processes were analysed using spectrophotometric method, whereas the mechanism of stability was estimated using adsorption process (spectrophotometry, FTIR). The obtained results show that CGG is able to adsorb on the surface of zirconia and also can form complexes with each of the studied anionic surfactants. However, the affinity of these complexes towards the zirconia surface is different, what causes significant differences in stability of the zirconia/CGG/surfactant suspensions. In order to get some information of the structure and charge of the formed complexes the surface tension and the zeta potential measurements were used as supporting techniques. Among the studied polymer-surfactant systems, the complexes between CGG and sodium dodecyl sulphate (SDS) adsorbed on the zirconia surface the most effectively, and the consequence of this phenomenon was the increase of stability in this system.

Dual-emission samarium macrocycle as a lab-on-a-molecule enables high-throughput discrimination of anionic sulfonate surfactants

Nowadays, it is still a huge challenge to efficiently discriminate of analogous anionic sulfonate surfactants, which are noxious xenobiotics related to many safety concerns of environment and life. Recently, great advances in orthogonal detection have shown the great advantages of principal component analysis (PCA) to construct a comprehensive statistical method for sensing signals in recognizing more analytes with similar structures. Inspired by sensor arrays, we propose a new ‘one-element-two-channel’ protocol upon a dual-emission samarium macrocycle Sm-2o as the lab-on-a-molecule, containing two isolated emissions of macrocycle (443 nm) and Sm(III) (643 nm) emitters as two fluorescence channels. Herein, these targeted surfactants instruct original fluorescences of Sm-2o to generate diverse sensing signals which can finally convert into unique fingerprint patterns and distinguish four anionic surfactants (SDS, SDSO, SCI and AOS) from other ten ones, even their proportional concentrations. Significantly, this high-throughput discrimination is realized by different receptor-analyte interactions and the structure transformation of Sm-2o in diverse microenvironments formed in various types of surfactants. Furthermore, these sensing systems also show satisfactory discrimination and semiquantitation performances for mixtures of anionic surfactants, especially the SDS and SDBS, in real water sample, revealing the practicability of our lab-on-a-molecule probe. On the basis of the PCA method, this work provides a vital reference for the design and application of multianalyte chemosensors.

Mixtures of anionic surfactants with single/triple polyoxyethylene chains and Gemini quaternary ammonium surfactant: interaction and surface activity studies

The combination of anionic and cationic surfactants can obtain high surface activity so that it has been widely used in many fields. However, the problem of ease to precipitate in the isoelectric mole ratio limits its further application. The introduction of polyoxyethylene chain into anionic surfactant and the use of Gemini quaternary ammonium surfactant can solve this problem origin from excessively strong interaction to a great extent while maintaining the best surface activity of the mixed system. Single polyoxyethylene chain carboxylate and triple polyoxyethylene chains sulfonate surfactants are mixed with Gemini quaternary ammonium surfactant respectively and their interactions are explored. The experimental results show that the complex of anionic surfactants with single or triple polyoxyethylene chains and Gemini quaternary ammonium surfactant can obtain high surface activity. And the polyoxyethylene group weakens the charge density of hydrophilic head groups of anionic surfactants. The branched polyoxyethylene chains will weaken this weakening effect. Excessively large steric hindrance of surfactant may reduce the stability and surface activity of mixed system. For anionic nonionic surfactants, the single chain structure and the appropriate numbers of polyoxyethylene groups are more conducive to compounding with Gemini quaternary ammonium surfactants to obtain the best surface activity and the most stable solution.

Dodecagonal quasicrystals of oil-swollen ionic surfactant micelles

A delicate balance of noncovalent interactions directs the hierarchical self-assembly of molecular amphiphiles into spherical micelles that pack into three-dimensional periodic arrays, which mimic intermetallic crystals. Herein, we report the discovery that adding water to a mixture of an ionic surfactant and n-decane induces aperiodic ordering of oil-swollen spherical micelles into previously unrecognized, aqueous lyotropic dodecagonal quasicrystals (DDQCs), which exhibit local 12-fold rotational symmetry and no long-range translational order. The emergence of these DDQCs at the nexus of dynamically arrested micellar glasses and a periodic Frank-Kasper (FK) σ phase approximant sensitively depends on the mixing order of molecular constituents in the assembly process and on sample thermal history. Addition of n-decane to mixtures of surfactant and water instead leads only to periodic FK A15 and σ approximants with no evidence for aperiodic order, while extended ambient temperature annealing of the DDQC also reveals its transformation into a σ phase. Thus, these lyotropic DDQCs are long-lived metastable morphologies, which nucleate and grow from a stochastic distribution of micelle sizes formed by abrupt segregation of varied amounts of oil into surfactant micelles on hydration. These findings indicate that molecular building block complexity is not a prerequisite for the formation of aperiodic supramolecular order, while also establishing the generic nature of quasicrystalline states across metal alloys and self-assembled micellar materials.