Journal of Surfactants and Detergents最新文献

Several industrial fields use emulsifiers in their products, with the ones of natural origin gaining increasing relevance. Identifying and using diversified sources for their extraction is a pertinent topic regarding sustainability principles, biodiversity preservation, or cost rationalization. This is the case of Quillaja bark saponin (QS), for which saponin-rich extracts, for example, Tribulus terrestris (TT), are being highlighted as viable alternatives, even though constraints like performance are still on the table. In this context, an experimental design using binary emulsifier mixtures of TT with pure QS was carried out by changing their composition (50–90%wt. TT), content (1.5–4.5%wt.), and high-pressure homogenization conditions (5–15 cycles). The emulsions were characterized by zeta potential, morphology, droplet size, and stability (expressed as the number of days without creaming formation). Moreover, the cream index for 30 days was determined to indicate the destabilization extent. The zeta potential showed stable emulsions (values below −41 mV); even still, creaming formed for samples using a low emulsifier and high TT contents. The emulsions' mean droplet diameter (D [3, 2]) was between 78 and 921 nm, with smaller sizes agreeing with higher stability. The statistical analysis indicated an optimum composition range comprising an emulsifier content between 3.9 and 4.5%wt. and TT content between 50 and 56%wt. to reach stable products. Overall, TT can provide an effective solution when combined with QS, decreasing the dependence on Quillaja bark.

The solubilization of butylated hydroxyanisole (BHA) in aqueous surfactant solutions of different architectures (anionic, cationic, and nonionic) has been investigated to improve its aqueous solubility and assess the effect of surfactant-based multiphase environments on its antiradical activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH). Herein, we report that the micellar encapsulation and DDPH antiradical activity of BHA are highly dependent on the structure and amount of surfactant used. Radical scavenging activity (RSA) and solubilization were efficient in nonionics compared to ionics. DPPH reduction kinetics in micellar media is essential to uncover the behavior of BHA in multiphase environments commonly encountered in different food systems simulated by aqueous micelles. The study is important to identify the optimal medium for improving the solubility and antioxidant capacity of compounds like BHA, and to anticipate the effect of different micro-heterogeneous/multiphase environments on BHA's antioxidant capability.

Surfactants are usually used as grinding aids. However, surfactant foaming during the grinding process is rarely mentioned in the literature with no clarification of its effect on the grinding process. In this paper, the generation of foam during the grinding of talc and quartz, as two different minerals in their hardness and hydrophobicity, was observed in the presence of sodium dodecyl sulfonate (SDS). The effect of generated foam on the fineness of ground product under different grinding conditions such as solids%, grinding time, and pulp pH was investigated. The results indicated that the foam was formed during the grinding of both minerals. The foam volume depends not only on the presence of surfactant but also on the characteristics of the mineral along with grinding conditions. The foam was intense and more stable particularly at pH 10 and high solid content (i.e., 60% solids) in the case of talc due to its fineness and hydrophobicity that result in bubbles stabilization. Remarkably, there is no foam at acidic pH due to the high ionic strength that leads to bubble instability. Most importantly, the presence of surfactant foams improves the size reduction process by providing more dispersion of particles, as one of the grinding aid mechanisms, due to particle-particle and particle-SDS repulsive electrostatic forces.

Three biobased, CO₂-consuming, and carbamate-groups-containing surfactants (CC-G, CC-T, CC-L) were synthesized separately by combination of Cardanol, CO₂, Glycine sodium salt (G), Taurine sodium salt (T), and Lysine sodium salt (L). The chemical structures of CC-G, CC-T, CC-L were confirmed by ¹H NMR and IR spectra. Thermal properties of these surfactants were studied with TGA and DSC. Their critical micelle concentration (CMC) and surface tension at CMC ($��{\rm Y}�$_CMC) in aqueous solution were obtained by surface tension and conductivity methods, respectively. The amount of excess concentration ($��{\Gamma }_{\max }�$) and the average occupied surface area ($��A_{\min }�$) of three surfactants were calculated. $��{\Gamma }_{\max }�$ of CC-G, CC-T and CC-L was 2.35 × 10⁻⁷ mmol/m², 2.23 × 10⁻⁷ mmol/m², and 6.16 × 10⁻⁷ mmol/m², separately. $��A_{\min }�$ of CC-G was 0.71 nm²/mmol, CC-T 0.74 nm²/mmol, CC-L 2.70 nm²/mmol. The Krafft point, emulsification, and foaming power of these surfactants were investigated as well. The Krafft points were 0°C (CC-G), 5°C (CC-T) and 20°C (CC-T). For CC-G, the separation time of 10 mL double distilled water (DDW) was 43 min, CC-T 40 min, and CC-L 37 min. It was inferred from the calculated packing parameters that shape of the micelle of CC-G, CC-T were cylindrical in aqueous media, while CC-L was spheroidal in aqueous media.

The optimum formulation in a surfactant–oil–water (SOW) system is defined as the physicochemical situation at which the surfactant adsorbed at the interface exhibits exactly equal interactions for both oil and water. Identifying the optimum formulation of SOW systems is crucial in various industrial applications, ranging from pharmaceuticals to cosmetics and to petroleum issues like dehydration and enhanced oil recovery. Multiple techniques are available to identify the optimum formulation, often with its own advantages and limitations. In this comprehensive review, we provide an in-depth analysis of the systematic use of formulation scans to identify the optimum formulation in SOW systems. We critically assess different methods, including conventional ones, such as phase behavior observation, determination of the minimum interfacial tension from equilibrated systems, and the localization of the minimum emulsion stability using formulation scans. We also mention a new promising technique that can be applied in practice, such as oscillating spinning drop interfacial rheology (OSDIR) as well as others that allow an understanding of some structural features of the domains present in the surfactant-rich phase in SOW systems. Among these methods, dynamic light scattering (DLS), small angle scattering (SAXS and SANS), nuclear magnetic resonance (NMR), X-ray microcomputed tomography (Micro-CT), and differential scanning calorimeter (DSC), can be found in the literature. Finally, we discuss potentially unusual behaviors that can appear in complex systems, thus providing guidance on the selection of the most suitable method tailored to the specific application.

The aim of our work is the preparation of cellulose nanofibrils or nanocrystals made from cellulose that is recovered from sugarcane bagasse agricultural waste (SC) as a dispersant instead of commercial cellulose for oil spill cleanup. In the current study, carboxymethyl cellulose was prepared by cellulose mercerization, which was then esterified by oxalic acid to create nanocellulose. Incorporation of oxalate into carboxymethyl cellulose (CMC) was verified by ¹H-NMR spectroscopy by the appearance of a new peak at 8.15 ppm for CMC–oxalate. The degree of substitution (DS) of oxalate was 0.17. The synthesized nanocellulose formed particles were roughly the same size and shape as both cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs): measuring 321–480 nm in length and 4–5 nm in width. Emulsions of paraffins made from CMC–oxalate are stable up to 10 months without undergoing precipitation. CMC–oxalate had great thermal stability and worked well as a paraffin oil dispersant. CMC–oxalate provided a barrier around the oil droplet surface, which prevented droplets from coalescing. This hypothesis is supported by the contact angle measurement for the O/W emulsion formed by CMC–oxalate being 0°, which is lower than the value for emulsions formed by underivatized CMC, 37.20°. From transmission electron microscopy observations, O/W emulsions of paraffin oil were spherical in shape, and separated from each other by a distance of 30–100 nm. This study shows that CMC–oxalate can be prepared by a low-cost method, yielding nanocellulose with characteristics that resemble CNFs and CNCs, thereby opening up new potential applications for cellulose nanomaterials.

Heterocyclic-based cationic surfactants with dodecyl tail group bridged to the head group either via aromatic ether [3-(4-dodecyloxybenzyl)-1-methyl-imidazolium bromide (Ar-I) and 4-(4-dodecyloxybenzyl)-4-methyl-morpholinium bromide (Ar-M)] or via aliphatic ether [3-(2-dodecyloxyethyl)-1-methyl imidazolium bromide (Al-I) and 4-(2-dodecyloxyethyl)-4-methyl morpholinium bromide (Al-M)] were synthesized and characterized using different spectral techniques. For the synthesis of Ar-I and Ar-M, 4-hydroxybenzoic acid was esterified initially, followed by O-alkylation, reduction, bromination and finally quaternization either with 1-methylimidazole or with 4-methylmorpholine. For the synthesis of aliphatic analogues (Al-I and Al-M), ethylene glycol was initially alkylated, followed by tosylation, bromination and quaternization either with 1-methylimidazole or with 4-methylmorpholine. Synthesized surfactants were evaluated for surface and self-assembly properties. Impact of the presence or absence of phenyl ring bridging the polar head and nonpolar tail of the surfactant and also type of heterocyclic moiety in the head group region on micellization and surface properties such as wetting, foaming and emulsification was studied. Surfactants with the bridged aromatic ether moiety were observed to display lower critical micelle concentration than those with the bridged aliphatic ether moiety irrespective of type of heterocyclic molecule in the head group region. Foam volume and stability of the aromatic ether-bridged surfactant were observed to be superior to their corresponding aliphatic analogs. Similar trend was observed in stabilizing the emulsion. However, aromatic ether-bridged surfactant depicted poor wetting ability compared to their aliphatic analog. Aliphatic ether bridged surfactant showed higher aggregation number compared to their aromatic counterparts, but depicted similar micellar core polarity.

The blockage caused by liquid loading poses a major problem to the aged gas wells. Various categories of foaming surfactants including zwitterionic, anionic and cationic surfactants are often used for foam-based gas well deliquification. In this study, a foaming formula containing anionic (sodium lauroyl sarcosinate, LSS), cationic Gemini (C₁₆AGB and C₁₂AGB) and zwitterionic (C₁₆APB and C₁₂APB) surfactants was developed. This foaming formula was first optimized through the foaming ability and foam stability tests, and then evaluated through liquid unloading performance tests under various salinity, condensate, methanol and temperature conditions. Synergy was observed in the foaming ability and foam stability measurements when LSS, C₁₆AGB, C₁₂AGB, C₁₆APB and C₁₂APB were combined at a molar ratio of 5:4:1:4:1. The foaming formula exhibited excellent liquid unloading performance at high salinity (up to 26 × 10⁴ mg/L), high condensate fraction (up to 25%) and high methanol fraction (up to 50%) conditions. The presence of 10% methanol significantly enhanced foaming efficiency (referred to as the ratio of the foam mass to the initial liquid mass) and liquid unloading efficiency of the foaming formula at 20–90°C. Furthermore, the surface tension measurements and the foam morphological investigation were carried out to reveal the observed synergy.

The interaction between novel saponification products (RCOONa or RCOOK) of Robinia pseudoacacia seed oil and cetyltrimethyl ammonium bromide (CTAB) in aqueous solution have been investigated by surface tension method at 25°C. The critical micelle concentration (cmc) of RCOONa/CTAB and RCOOK/CTAB mixture were measured. The surface properties of saponification products, CTAB as well as the mixed system were explored and compared. The composition, activity coefficient of mixed micelle, and the interaction parameters (β^σ, β^M) between surfactants were estimated according to the Regular Solution Theory, the Clint's model and the Rubingh's model in the framework of pseudophase separation model. The experimental results suggested that both RCOONa and RCOOK have synergism with CTAB in mixed micelle formation and surface tension reduction through calculating of β^σ and β^M in the mixed system. This could be attributed to the strong interaction between the head groups with opposite charges in the surfactant molecules.