Surfactant Water Research Articles

Modeling and optimization of stability aspects for water diesel emulsified fuel using response surface methodology

ABSTRACT In the scenario of energy crisis and fall in environmental aspects, water diesel emulsified fuel (WDEF) acts as a promising alternative fuel. For improving the stability of emulsified fuel, optimization of the emulsification process should be performed. In this study, experimental and statistical analysis was executed to optimize the stability aspects of WDEF through response surface methodology (RSM) approach. Further, experimental investigations were carried out for performance, emission, and combustion features of the diesel engine by using optimized WDEF. The design of experiments was carried out by considering water concentration, surfactant concentration, and duration of ultrasonication as input parameters of the emulsification process. Their effects on the separation of water layer were inspected experimentally. The quadratic model was developed and confirmed for analysis of variance (ANOVA). Interactive effects of input parameters were plotted by using the regression model. The estimated optimum values of water concentration, surfactant concentration, and duration of ultrasonication were found to be 4.486% vol., 1.237% vol., and 30.0 min, respectively. The performance and combustion features showed the marginal difference between neat diesel and the emulsified fuel. The emissions of NOX, smoke, CO, and HC were reduced tremendously as compared to neat diesel.

A multi-family offline SPE LC-MS/MS analytical method for anionic, cationic and non-ionic surfactants quantification in surface water

Of the large number of emerging pollutants discharged from wastewaters into surface waters, surfactants are among those with the highest concentrations. However, few monitoring in river waters of these substances have already been performed and only on a few families, mostly anionic.This work aimed to develop a multi-family analytical strategy suitable for the quantification of low concentrations of surfactant in surface waters. Twelve families of surfactants, anionic, cationic and non-ionic were selected. Their quantification by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and their extraction by SPE were optimized by comparing different retention mechanisms. The best performances were obtained with a C18 grafted silica LC column and a hydrophilic-lipophilic balanced (HLB) polymeric SPE cartridge.The final analytical method was validated and applied for the quantification of surfactants in 36 river water samples. Method limits of quantification (LQ), intra and inter days precision and trueness were evaluated. With LQ between 15 and 485 ng/L, and trueness over 80%, this method was suitable for monitoring surfactants in surface water. Application on French river water samples revealed the presence of anionic, cationic and non-ionic surfactants with median concentrations from 24 ng/L for octylphenol ethoxylates (OPEO), up to 4.6 μg/L regarding linear alkylbenzene sulfonates (LAS).

Utilizing Nanofluid to Enhance Thermosyphon Heat Pipe Thermal Efficiency

This is a study on the enhancement of the thermal performance of a thermosyphon heat pipe (THP) using the nanoparticle in a mixture of water and Triton X-100 (TX-100) surfactant. The effects of nanoparticle concentration, surfactant concentration, input power, inclination angle, and filling ratio on the thermal efficiency of THP is evaluated experimentally. Experiments were designed by the Taguchi method using Minitab software. According to the results, utilizing a nanofluid/surfactant mixture decreases the evaporator’s temperature, which decreases the thermal resistance and increases the thermal efficiency of THP. The maximum enhancement of thermal efficiency was observed to be 17.7%, and the maximum decrease in thermal resistance was 42.5% using the optimum concentration of nanofluid and TX-100 compared to water. The maximum thermal efficiency predicted by the Taguchi method was 0.8877, which was in good agreement with the experimental value of 0.917.

Phase separation phenomena and thermodynamics of octylphenol polyoxyethylene ether in micellar solutions: Effect of high concentration of inorganic salts and linear correlation

The phase separation phenomena or cloud points (CP) behavior of nonionic octylphenol polyoxyethylene ether with oxyethylene glycol ether unit of 15 (OP-15) were investigated in aqueous micellar solutions containing high concentrations of inorganic salts including NaCl, KCl, MgCl2, CaCl2, BaCl2, AlCl3, FeCl3, Na2SO4 and Na2SiO3. The change in CP induced by salts and its mechanism are discussed theoretically. In aqueous solutions containing high concentration of salt, for the first time the linear relationship between CP and salt concentration is well established to characterize the depression of CP. Based on pseudo phase separation model, thermodynamic parameters are estimated and adopted to further describe the phase separation process and the interactions between OP-15 molecules or the OP-15/water interactions. Thermodynamic parameters including standard Gibbs energy change (ΔGCP0), enthalpy change (ΔHCP0) and entropy change (ΔSCP0) indicate that the additions of different salts result in the change in entropy-driven nonspontaneous process of phase separation. These data, which are from the compensation temperatures and the change of molar heat capacity, also prove that different ions induce the change in the interactions between surfactant molecules or the surfactant–water interaction and thus affect the depression of CP. These findings help with understanding the effect of inorganic salts, especially the high concentration of salt, on CP of nonionic surfactant and then broadening the application of nonionic surfactant based on CP such as the extraction of biomaterials in biological samples derived from animals or plants, etc.

Selective removal of over-paintings from “Street Art” using an environmentally friendly nanostructured fluid loaded in highly retentive hydrogels

HypothesisThe removal of over-paintings or graffiti is a priority for conservators and restorers. This operation is complex, especially when over-paintings lay on painted surfaces that must be preserved, as in the case of vandalism on street art, where the layers are usually chemically similar. Traditional methodologies often do not provide satisfactory results and pose health and eco-compatibility concerns. An alternative methodological approach based on an environmentally friendly nanostructured fluid loaded in a retentive hydrogel is here proposed. ExperimentsSix paints (based on vinyl, acrylic and alkyd polymers) were selected and studied by means of attenuated total reflection - Fourier transform infrared spectroscopy. The phase behavior of four alkyl carbonates (green, low-toxicity organic solvents) and a biodegradable nonionic surfactant in water was investigated with Small angle X-ray scattering (SAXS) in order to formulate a novel nanostructured cleaning system. The developed system, which also includes 2-butanol and an alkyl glycoside hydrotrope, was loaded in highly retentive hydrogels and tested in the selective removal of over-paintings from laboratory mockups and from real pieces of street art. FindingsThe selective and controlled removal of modern paints from substrates with similar chemical composition has been achieved using a specifically tailored NSF embedded in a retentive hydrogel. The proposed methodology and cleaning system provided excellent cleaning results, representing a new tool for the conservation of contemporary and, in particular, street art.

“TPG-lite”: A new, simplified “designer” surfactant for general use in synthesis under micellar catalysis conditions in recyclable water

Using the oxidized, carboxylic acid-containing form of MPEG-750, esterification with racemic vitamin E affords a new surfactant (TPG-lite) that functions as an enabling, nanoreactor-forming amphiphile for use in many types of important reactions in synthesis. The presence of a single ester bond is suggestive of simplified treatment as a component of (eventual) reaction waste water, after recycling. Many types of reactions, including aminations, Suzuki-Miyaura, S N Ar, and several others are compared directly with TPGS-750-M, leading to the conclusion that TPG-lite can function as an equivalent nanomicelle-forming surfactant in water. Prima facie evidence amassed via DLS and cryo-TEM analyses support these experimental observations. In silico evaluations of the aquatic toxicity and carcinogenicity of TPG-lite indicate that it is safe to use.

One-Pot synthesis of modified-cationic surfactants for enhanced oil recovery applications in carbonate reservoirs

In this study two cationic surfactants, dodecyltriethylammoniumbromide (C12TEAB) and hexadecyltriethylammoniumbromide (C16TEAB) were prepared. The formation of synthezied surfactants were confirmed using FTIR and HNMR spectroscopy. Electrical conductivity, interfacial tension and surface tension methods were used to determine the critical micelle concentrations (CMC) of these surfactants. To understand the behavior of synthesized surfactants in harsh environments, the CMC was measured in deionized water (DIW), sea water and petroleum formation water. Using electrical conductivity technique, for C12TEAB surfactant the CMC values of 4000 ppm, 2000 ppm and 850 ppm were recorded in DIW, sea water and formation water respectively. For C16TEAB surfactant, the CMC values of 420 ppm, 190 ppm and 115 ppm were obtained in DIW, sea water and formation water respectively. The similar CMC results were obtained using the interfacial tension (IFT) and surface tension (ST) methods. Reduction of IFT between crude oil and formation water and also alteration of wettability of petroleum reservoir of carbonated rock from oil-wet (large contact angle) to water-wet (small contact angle) are two major factors affecting chemical enhanced oil recovery (EOR). Interfacial tension (IFT), surface tension (ST) and contact angle measurements were carried out using an IFT-PDSA-06 apparatus (Apex Technologies Company, Iran). The IFT and ST of these surfactants were also carried out in DIW, sea water and formation water. For C12TEAB surfactant, the IFT values of 0.051 mN/m, 0.036 mN/m and 0.023 mN/m were recorded in DIW, sea water and formation water respectively. The IFT values of 0.044 mN/m, 0.026 mN/m and 0.0126 mN/m were measured for C16TEAB surfactant in DIW, sea water and formation water respectively. The effect of temperature on IFT was studied for both surfactants. When temperature increases, IFT decreases. The reduction of IFT continues up to 55 °C, then the IFT increases with increasing temperature. For C12TEAB surfactant, the ST values of 44.9 mN/m, 38.8 mN/m and 31.8 mN/m were obtained in DIW, sea water and formation water respectively. In similar measurements for C16TEAB surfactant, the recorded ST values were 33.95; 32.9 and 32.22 mN/m in DIW, sea water and formation water respectively. In wettability alteration study both surfactants altered the contact angle from oil-wet to water-wet conditions. Using formation water and C12TEAB surfactant, the contact angle varied from 96.4° to 54.5°. In similar study using C16TEAB surfactant the contact angle changed from 92° to 46.1°. The contact angles of these surfactants in DIW and sea water were also measured and reported. The results of IFT and wettability studies demonstrated excellent potential application of synthesized surfactants in EOR process in carbonate petroleum reservoirs.

Asymptotic dynamics of a sixth-order integro-differential equation

We consider a sixth-order integro-differential equation with periodic boundary conditions. The equation describes the phase transition dynamics in ternary oil–water–surfactant systems. Using the energy methods and the basic dissipative estimate, we establish the required estimates. Furthermore, based on these estimates, we prove the existence of the attractors by a decomposition of the solution semigroup.

Deep learning the sound of boiling for advance prediction of boiling crisis

Summary Advance prediction of boiling crisis is critical to the safety and economy of many thermal systems. Here, we perform steady-state near-saturated boiling experiments on a plain copper surface and acquire the acoustic emissions (AEs) in natural convection, nucleate, and transition boiling regimes. We use the corresponding AE spectrograms to train a convolutional neural network, which shows a validation accuracy of 99.92% against the ground truth. We next evaluate the trained network on experiments with water and aqueous solutions of ionic liquid and surfactant on plain and nanostructured copper surfaces with time-varying heat inputs. Despite the variations in boiling surfaces, working fluids, and the heating strategy between the training and the evaluation datasets, the network accurately predicts the respective boiling regimes. Finally, we use the insights to perform advance prediction of boiling crisis for mitigating thermal runaway-induced accidents in boiling-based systems.

Efficiency of microbubble production using surfactants for the treatment of oily water by flotation

Microbubble flotation is a process for the treatment of oily water that requires attention to the variables of the oil removal process. In the present study, experimental designs were applied to a microbubble generation and measuring unit. The factors selected for optimization of the microbuble production were water flow rate, airflow rate, pH, and surfactant concentration. The response variables were dynamic Sauter diameter (DSD), static Sauter diameter (SSD), and microbubble haze height (MHH). Factor planning (central composite rotational design) was used to determine the behavior of the microbubbles in the absence of surfactant as the collector (fluid dynamic planning) as well as in the presence of the synthetic surfactant sodium dodecyl sulfate (chemical planning) or a microbial surfactant produced by the bacterium Pseudomonas cepacia (biological planning). Motor oil (200mgL−1) was added to the best assay of each type of factor planning. The results indicated that the assays with the chemical surfactant were the best conditions compared with the assays without surfactant and with the biosurfactant. The addition of the oil reduced the Sauter mean diameter of the microbubbles to a minimum of 14μm. Therefore, the 71 assays enhanced microbubble production efficiency, enabling better oily water treatment in flotation systems.

Determination of Critical Micelle Concentration from the Diffusion-Driven Dilution of Micellar Aqueous Mixtures.

Micellization is a phenomenon of central importance in surfactant solutions. Here, we demonstrate that the diffusion-based spreading of the free boundary between a micellar aqueous solution and pure water yields a one-dimensional spatial profile of surfactant concentration that can be used to identify the critical micelle concentration, here denoted as C*. This can be achieved because dilution of micelles into water leads to their dissociation at a well-defined position along the concentration profile and an abrupt increase in the diffusion coefficient. Rayleigh interferometry was successfully employed to determine C* values for three well-known surfactants in water at 25 °C: Triton X-100 (TX-100), sodium dodecyl sulfate (SDS), and poly(oxyethylene)(4)Lauryl Ether (Brij-30). The dependence of C* on salt concentration was also characterized for TX-100 in the presence of Na2SO4, NaCl, and NaSCN. Accurate values of C* can be directly identified by visual inspection of the corresponding concentration-gradient profiles. To apply the method of least squares to experimental concentration profiles, a mathematical expression was derived from Fick's law and the pseudophase separation model of micellization with the inclusion of appropriate modifications. While Rayleigh interferometry was employed in our experiments, this approach can be extended to any experimental technique that yields one-dimensional profiles of surfactant concentration. Moreover, diffusion-driven surfactant disaggregation is precise, noninvasive, requires single-sample preparation, and applies to both nonionic and ionic surfactants. Thus, this work provides the foundation of diffusion-driven dilution methods, thereby representing a valuable addition to existing techniques for the determination of C*.

Optimisation of food grade mixed surfactant-based l-ascorbic acid nanoemulsions using response surface methodology.

Co‐surfactant free l‐ascorbic acid (LAA) nanoemulsions were prepared using mixed surfactants (Soya lecithin and Tween 80). Response surface methodology (RSM) was used to optimise the emulsifying conditions for LAA nanoemulsions. The effects of water proportion (6%–14% w/w), homogenisation pressure (80–160 MPa), surfactant concentrations (4%–12% w/w) and laa concentration (0.5–1.3 w/w) on responses (size of droplets and nanoemulsion stability) were investigated. RSM results showed that the values of responses can be successfully predicted through second‐order polynomial model. The coefficients of determinations for droplet size and nanoemulsion stability were 0.9375 and 0.9027, respectively. The optimum preparation conditions for l‐LAA nanoemulsion were 9.04% water proportion, 114.48 MPa homogenisation pressure, 7.36% surfactant concentration and 1.09% LAA concentration. At the end of one month storage study, the retention of LAA in optimised nanoemulsions stored at 4°C and 25°C were 74.4% and 66.7%, respectively. These results may provide valuable contributions for food and pharmaceutical industry to develop delivery system for food additives and nutraceutical components.

Preparation of a reference material for microplastics in water\u2014evaluation of homogeneity

Validation of analytical methods for measurements of microplastics (MP) is severely hampered because of a general lack of reference materials, RM. There is a great need to develop such reference materials. This study presents a concept of three-component kit with immobilised MP in solid NaCl, a surfactant and clean water that can be applied for the production of many types of MP RMs. As proof of concept, an RM for polyethylene terephthalate (PET) particles in water was prepared and evaluated for its homogeneity. The particles ranged from 30 μm (Feretmin) to about 200 μm adapted by wet sieving. A specific number of PET particles were immobilized in about 0.29 g of solid NaCl by freeze-drying 1 mL of a NaCl suspension. By using manual and automated counting, twenty reconstituted 1-L water samples were evaluated for homogeneity with respect to number of PET particles from 30 μm to > 200 μm/L of water. The number of particles was 730 ± 120 (mean ± one standard deviation (SD); n = 10) and 865 ± 155 particles (n = 10) obtained by optical microscopy in two independent laboratories. This corresponded to relative SDs of 16.4 and 17.9% and a mean of 797 ± 151 particles (18.9% RSD, for n = 20). Homogeneity studies of the NaCl carrier without reconstitution resulted in 794 ± 60 particles (7.5% RSD). The homogeneity of PET in the salt carrier was also evaluated directly with respect to mass of PET per vial using an ultra-micro balance. An average mass of 293 ± 41 μg of PET was obtained (14, % RSD for n = 14). Micrographs were recorded to demonstrate the absence of major sources of contamination of the RM components. Information about the particle size distribution and particle shapes was obtained by laser diffraction (LD) and dynamic image analysis (DIA). In addition, the identity of the PET polymer was confirmed by Raman and FT-IR spectroscopy. The RM was developed for a large-scale inter-laboratory comparison of PET particles in water (ILC). Based on the homogeneity results, the material was found to be sufficiently homogeneous to be of meaningful use in the ILC. In a 3-day process, more than 500 samples of PET particles in the NaCl carrier were prepared with good potential for further upscaling with respect to the number of vials or with other kinds of polymers. The stability of PET was not evaluated but it was deemed to be stable for the duration of the ILC.

An experimental study on heat transfer of different aqueous surfactant solutions horizontal impinging jet using infrared thermography

This paper reports the effect of surface wettability on heat transfer characterizes of the impinging jet using the infrared thermography. Tests are performed on a heated vertical stainless steel foil of 0.15 mm thickness (SS-304) by circular horizontal impinging jets of pure water and various aqueous surfactant solutions such as 2-Ethyl Hexanol (2-EH), 1-Octanol (1-Oct) and Sodium-Dodecyl Sulfate (SDS) at varied surfactant concentration (100–400 ppm). The effect of wettability enhancement in heat transfer is disclosed by the heat transfer study using the thermal image detected by the infrared thermography system (A655sc, FLIR System). At a similar time period (t = 0.2 sec) after impingement, the liquid spreading is found to grow by a maximum of 3.1 times for 2-EH and 2.4 times for SDS. New empirical correlations are presented using regression analysis for the enhancement of radial impingement zone (Ra/Ro) and the ratio of heat transfer coefficient of water with additives (had) with the heat transfer coefficient for pure water (hpw).

Maltose-Based Fluorinated Surfactants for Membrane-Protein Extraction and Stabilization.

Two new surfactants, F5OM and F5DM, were designed as partially fluorinated analogues of n-dodecyl-β-D-maltoside (DDM). The micellization properties and the morphologies of the aggregates formed by the two surfactants in water and phosphate buffer were evaluated by NMR spectroscopy, surface tension measurement, isothermal titration calorimetry, dynamic light scattering, small-angle X-ray scattering, and analytical ultracentrifugation. As expected, the critical micellar concentration (cmc) was found to decrease with chain length of the fluorinated tail from 2.1-2.5 mM for F5OM to 0.3-0.5 mM for F5DM, and micellization was mainly entropy-driven at 25 °C. Close to their respective cmc, the micelle sizes were similar for both surfactants, that is, 7 and 13 nm for F5OM and F5DM, respectively, and both increased with concentration forming 4 nm diameter rods with maximum dimensions of 50 and 70 nm, respectively, at a surfactant concentration of ∼30 mM. The surfactants were found to readily solubilize lipid vesicles and extract membrane proteins directly from Escherichia coli membranes. They were found more efficient than the commercial fluorinated detergent F6H2OM over a broad range of concentrations (1-10 mM) and even better than DDM at low concentrations (1-5 mM). When transferred into the two new surfactants, the thermal stability of the proteins bacteriorhodopsin (bR) and FhuA was higher than in the presence of their solubilization detergents and similar to that in DDM; furthermore, bR was stable over several months. The membrane enzymes SpNOX and BmrA were not as active as in DDM micelles but similarly active as in F6OM. Together, these findings indicate both extracting and stabilizing properties of the new maltose-based fluorinated surfactants, making them promising tools in MP applications.

Self – assembly of model surfactants as reverse micelles in nonpolar solvents and their role as interfacial tension modifiers

The self-assembly of linear surfactants into reverse micelles (RMs) in nonpolar solvents, and their efficiency in reducing the interfacial tension is studied using dissipative particle dynamic simulations. Given the importance of RMs as thickeners, among many other applications, their properties are studied here when formed in oil and in supercritical carbon dioxide (scCO2). Our simulations are found to be in agreement with experimental results of surfactant self-assembly in scCO2 that found viscosity increments of up to 90% with 10 wt % of surfactants. The role played by a small number of water molecules in RM formation is studied as well in both solvents, corroborating experiments reporting the enhancement of RM formation with the addition of a small quantity of water. The dynamics of water surfactant aggregation in nonpolar solvents is also discussed. Lastly, the performance of the model surfactant as an interfacial tension modifier is studied in detail. The results show that RMs are more easily formed in oil than in scCO2 and that the effectiveness of the surfactant in reducing the interfacial tension lies in its preference to adsorb at interfaces rather than self – association.

Experimental study of cavitation erosion of quartz in the presence of surfactant molecules

The interaction of bubbles with a solid flat surface of amorphous quartz, in the presence of surfactants in water, in the presence of ultrasonic action, was experimentally investigated. The study of surface properties with the use of an atomic force microscope made it possible to study the mechanism of ultrasonic degradation of the surface of solid plates, including those with surfactants adsorbed on their surface. The experiments have shown that the changes, under the action of ultrasound, of the surface properties, in these experiments, consist in the formation of chips on the surface of quartz crystals, which leads to an increase in the average surface roughness by three times in comparison with the plates that were not subjected to ultrasonic action. Was founded that the distribution of the surfactant layer on the surface of the plates depends on the concentration of the surfactant in the solution, and its presence at the solid-liquid interface leads to a decrease in the ultrasonic erosion of the plate surface. The mechanism of heterogeneous cavitation in the presence of surfactants is to reduce the probability of interaction between an inertial cavitation bubble and a solid surface, because of which the probability of local destruction of the surface decreases.

Identification and Determination of Nonionic Surfactants by Ultrahigh-Performance Liquid Chromatography–High-Resolution Mass Spectrometry

We proposed a procedure for the identification and determination of nonionic surfactants in natural waters by ultra-HPLC with high-resolution mass spectrometry detection. The main analytical characteristics of the determination of the most common nonionic surfactants—alkylphenol ethoxylates and alkyloxyethoxylates—are found by the proposed method. The main adducts of polymer homologues of the determined surfactants, formed under electrospray ionization, are considered. To extract analytes from natural water samples, we used dispersive liquid–liquid microextraction with a mixture of trichloromethane and acetonitrile. A possibility of the determination of nonionic surfactants by the direct electrospray of a prepared sample into a mass spectrometer is considered. The limits of quantification of surfactants under the selected conditions varied from 0.1 to 0.5 ng/mL; the analytical range was from 1 to 1000 ng/mL. The relative standard deviation of the results did not exceed 15%. The duration of the identification of sample components was 30 min; the determination of the detected analytes took 1 h.

A practical and economically feasible surfactant EOR strategy: Impact of injection water ions on surfactant utilization

One grand challenge of surfactant technologies in high salinity sandstone reservoirs is the surfactant retention and its utilization for commercial projects. A proven mitigation strategy to reduce surfactant retention is to soften the seawater or produced brine and add alkali with the surfactant and polymer. However, softening produced brine can be costly and the addition of alkali can impose other issues such as scale and produced fluid separation. A comprehensive chemical enhanced oil recovery (CEOR) laboratory program was carried out to compare different surfactant formulations for both alkali-surfactant-polymer (ASP) and surfactant-polymer (SP) implementation in a giant Middle East sandstone oil reservoir with high salinity on the order of 160,000 ppm. The efficacies of ASP and SP floods were investigated in laboratory corefloods and simulations with emphasis on surfactant retention to improve techno-economic feasibility.Both ASP and SP floods were designed with low operational cost in mind and were tested in laboratory corefloods under reservoir conditions. Different injection water salinities were considered for practical field application. The handling and availability of injection water with a suitable composition has significant implications in CEOR projects. The SP design using produced brine with minimum water treatment is an attractive option for field commercial deployment. We considered different injection water salinities, surfactant molecules, and brine treatment requirements for several ASP and SP formulations and injection design strategies.ASP and SP corefloods recovered nearly all the remaining oil after waterflooding. The surfactant retention was lower for SP floods when brine with reduced concentration of Ca2+ and Mg2+ (hardness) was used. Both ASP and SP formulations were also tested for crude oil samples from different zones. A minimal adjustment in injection salinity was required for different oils with our surfactant formulations. Field implementation strategies were evaluated via numerical simulation. The effect of strong aquifer drive on SP performance was shown to be minimized with optimized injection/production strategies. SP was shown to be technically and economically an attractive candidate tertiary process.

Composition dependent density of ternary aqueous solutions of ionic surfactants and salts

Surfactants exist in atmospheric aerosols mixed with inorganic salts and can significantly influence the formation of cloud droplets due to bulk–surface partitioning and surface tension depression. To model these processes, we need continuous parametrizations of the concentration dependent properties of aqueous surfactant–salt solutions for the full composition range from pure water to pure surfactant or salt. We have developed density functions based on the pseudo-separation method and Young’s mixing rule for apparent partial molal volumes for solutions that mimic atmospheric droplets of marine environments. The developed framework requires only model parameters from binary water–salt and water–surfactant systems and includes the effect of salinity on micellization with composition-dependent functions for the critical micelle concentration (CMC). We evaluate different models and data available in the literature to find the most suitable representations of the apparent partial molal volume of sodium chloride (NaCl) in aqueous solutions and the CMC of selected atmospheric and model surfactants in pure water and aqueous NaCl solutions. We compare model results to experimental density data, available in the literature and obtained from additional measurements, for aqueous solutions containing one of the ionic surfactants sodium octanoate, sodium decanoate, sodium dodecanoate or sodium dodecylsulfate mixed with NaCl in different relative ratios. Our model follows the experimental trends of increasing densities with increasing surfactant concentrations or increasing surfactant–salt mixing ratios both, below and above the CMC, capturing the effect of the inorganic salt on the surfactant micellization.