Volume 55, Issue 2

Polysorbate 80 and sodium lauryl ether sulphate mixtures are often used in personal care products especially in shampoo formulations. In this paper, the combined effect of sodium lauryl ether sulphate and salts (Na 2 SO 4 , NaCl, CaCl 2 ) and sodium lauryl ether sulphate and alcohols having different chain length on the cloud point of polysorbate 80 has been studied. The cloud point of a nonionic surfactant is influenced by the presence of additives. In the current system, a rise in the cloud point of polysorbate 80 was observed in the presence of ionic surfactant, sodium lauryl ether sulphate (0.010–0.050 mM) which is interpreted as increase in the surface charge of micelle. The cloud point of the sodium lauryl ether sulphate-polysorbate 80 mixture decreased with the addition of inorganic salts. The presence of short chain alcohols (C 1 –C 3 ) was found to increase the cloud point of polysorbate 80-sodium lauryl ether sulphate mixtures whereas, long chain alcohols (C 4 , C 5 ) were found to decrease the cloud point of polysorbate 80-sodium lauryl ether sulphate mixtures depending on their solubility in water.

Body wash cosmetics are among the most popular and numerous groups of cosmetic products. In chemical terms, they are solutions of surface active agents with the addition of multiple substances such as preservatives, moisturizing agents, fragrances or viscosity modifiers, the aim of which is to improve specific product properties. The present study evaluated the effect of the molecular weight of polyvinylpyrrolidone (PVP) on the properties of face washing products in the form of foam produced with foaming dispensers. A special focus was on key product quality characteristics including foaming properties and skin irritation potential. An addition of PVP to the formulation was found to contribute to an improvement in product foaming properties and a decrease in skin irritation potential. In addition, the studied properties of samples were shown to improve in proportion to the increasing molecular weight of the polymer.

Food-grade water in oil (W/O) microemulsions were developed and characterized in order to use them as potential tea polyphenols (TP) carriers. The physicochemical characteristics of microemulsions (TP-loaded and blank microemulsions) were investigated by rheological measurements, differential scanning calorimetry (DSC), dynamic light scattering (DLS) and 1 H nuclear magnetic resonance ( 1 H NMR). The thermal behavior of the microemulsion system implied that the water molecules were competitively bound. Chemical shift patterns for all samples were not sensitive to the addition of TP. The microscopic images showed that both the non-loaded and the TP-loaded microemulsions had a spherical shape, in particular the TP-loaded microemulsions had a specific core-shell morphology. TP solubilized in the microemulsions was much more stable than that dissolved in water solution. The release process of TP in water solution was faster than that of microemulsions.

The influence of alkyl-aldehydes upon electric percolation of AOT-based microemulsions has been studied. The number of carbons in the hydrocarbon chain was varied between 0 and 5 atoms (chain length between 0 and 7.33 Å). Two different behaviors were found, while the presence in the microemulsion of short chains aldehydes implies a decrease in the percolation temperature, aldehydes with 4 or 5 carbon atoms in the hydrocarbon chain increase the percolation threshold. This opposite behavior has been justified in terms of aldehyde location in the microheterogeneous system.

This study was focused on a ternary complex system composed of hexadecyl diphenyl ether disulfonate (C 16 -MADS), dodecyl dimethyl hydroxyethyl ammonium chloride (K 3 ) and fatty alcohol polyoxyethylene ether (AEO 9 ). The binary mixture C-K consisting of C 16 -MADS and K 3 was investigated and the maximum synergism was obtained when the mole ratio was 0.33:0.67. Subsequently, AEO 9 was added to the binary C-K complex system to investigate whether the behavior of the new complex system, in which C-K is thought to be a surfactant, can be explained by the theory of regular solution. The maximum synergism was achieved when the molar ratio of C-K and AEO 9 was 7:3. The regular solution theory could well explain the synergism in mixed micelle formation and the synergism in surface tension reduction efficiency, but the synergism in surface tension reduction effectiveness did not match with the experimental data. So, there still exist some deficiencies in the application of the regular solution theory to a complex system of three surfactants.

In this study, the synergistic effect of saponin and rhamnolipid biosurfactant on foam properties at an air-water interface was investigated. In order to reach the optimum hydrophilic lipophilic balance (HLB) value, samples of 2 wt% of rhamnolipid and saponin biosurfactants with different HLB values (9.6, 10, 10.4, 10.8, 11.2, 11.6, and 12) in 5 ml of DI water were prepared. Results showed that the optimum HLB value of the microemulsion system was 10.8 for the mixture of 84% rhamnolipid and 16% saponin. At that optimum HLB value and a total surfactant concentration of 2 wt%, the maximum foaming ability and foam stability of the mixed system was 48 mm and 72 min respectively. During the experiment, it was observed that at optimum HLB value the foaming ability of the system increased by increasing the concentration of rhamnolipid and saponin. Comparing the foaming ability and foam stability of biosurfactant system with the properties of SDS, Tween80 and Span80 showed that the biosurfactants have a good foaming ability. The CMC value of the biosurfactant mixtures at the optimum HLB value was lower than that of other synthetic surfactants. The results show that, the biosurfactant mixtures had a synergistic effect on foaming ability and foam stability compared to the individual biosurfactants and synthetic surfactants. Therefore, the mixture of rhamnolipid and saponin is proposed as a potential alternative for detergent, cosmetic and petroleum industry.

Ultrasonic velocities have been measured in ternary mixtures containing copper soaps derived from mustard and soya bean in 20% and 40% methanol-benzene mixture to access the effect of polarity of solvent on the micellar features of surfactant. The studies suggest that predomination of benzene (higher percentage of non-polar solvent) play a significant role in compacting the molecular organization of the micelles. From these values, the specific acoustic impedance Z, adiabatic compressibility β ad , intermolecular free length L f , apparent molar compressibility ϕ k , molar sound velocity R, primary solvation number S n have been calculated. The data clearly indicate that the values of u, Z, S n and R increase whereas the values of β ad and L f decrease consistently with increase of the soap concentration. The critical micelle concentration CMC has also been determined and it has been found that CMC is dependent on the composition of the solvent mixture and composition of the edible oil. The Masson equation has also been applied. The results have been explained on the basis of intermolecular interactions between solvent and solute.

Novel ethylenediamine triacetate (ED 3 A) chelating surfactants containing a flexible spacer whose general formula are of CH 3 (CH 2 ) x CH 2 OCH 2 CH(OH)CH 2 N(CH 2 COONa)CH 2 CH 2 N(CH 2 · COONa) 2 ( D1 : × = 10, D2 : × = 12) have been synthesized. The structures of their carboxylic acid derivatives ( C1 and C2 ) were characterized with electrospray ionization–mass spectrometry (ESI-MS), 1 H-NMR and 13 C-NMR. The values of the critical micelle concentration (CMC) of the two surfactants ( D1 and D2) are at level 10 −4 mol L −1 and the surface tension of the surfactant D1 solution at CMC is only 28.6 mN m −1 , which indicates a high surface activity of the D1 surfactant. The surfactants have good foaming, foam stabilizing and emulsifying properties for toluene. When eluting heavy metal contaminated soils with surfactant solution at a concentration of 0.1 mol L −1 , where the metals (Pb, Cu and Zn) are mainly in the presence of residual fraction, D1 and D2 can obtain the metal removal efficiencies of 27.82% and 28.19% for Pb, 24.73% and 24.00% for Cu, 9.12% and 8.61% for Zn, respectively. It is suggested that the two chelating surfactants can be used as elution agents to remediate heavy metal contaminated soils.

A novel betaine Gemini surfactant (B18-4-18) was synthesized by two-step reaction with N,N-dimethyl oleoaminde-propylamine, sodium 2-hydroxy-3-chloro propanesulfate and 1,4-dibromobutane as main raw materials. The structure of the synthesized betaine Gemini surfactant was characterized by Fourier transform infrared spectroscopy (FTIR) and 1 H nuclear magnetic resonance spectrum ( 1 HNMR), the surface tension curve and related parameters were obtained by surface tension measurements. The surface tension of oleamide hydroxypropyl betaine (B18) and the Gemini surfactant (B18-4-18) at different concentrations was measured. The experimental results showed that the structure of the synthesized compounds was in conformity with the expected structure of the surfactants. The critical micelle concentration of B18 was 6.1 × 10 −6 mol/L, the corresponding surface tension was 34.27 mN/m. The critical micelle concentration of B18-4-18 was 5.0 × 10 −6 mol/L, the corresponding surface tension was 31.67 mN/m at 25°C. The liquid carrying rate of B18 and B18-4-18 can reach 87% and 92% in water respectively. The liquid carrying rate of B18 and B18-4-18 can reach 82% and 84% in 150 000 mg/L mineralized water. The liquid carrying rate of B18 and B18-4-18 can reach 64% and 67% respectively at 10% condensate oil.

Sodium (Z)-15-carboxylato-8-(2-(((Z)-3-carboxylatoacryloyl)oxy) ethyl)-4,13-dioxo-5,11,12-trioxa-8,16-diazahentriacont-2-enoate has been synthesized. The chemical structure was confirmed by FT-IR and 1 HNMR spectroscopy. The surface properties of the synthesized trianionic surfactant, including the critical micelle concentration (CMC), effectiveness (π cmc ), maximum surface excess (Γ max ), and minimum surface area (A min ) were determined from surface tension measurements. The efficiency of the trianionic surfactant to remove Pb(II) was determined using a flotation cell at different surfactant concentrations (below, at and beyond the CMC). Flame atomic absorption spectroscopy was used to determine the initial and final concentrations of Pb(II) ions. At pH 6 and a foaming time of 2 hr, the removal efficiency of Pb(II) increases with increasing the trianionic surfactant concentration.

An emulsion of hydrocarbon components in water is usually found in the wastewater of refineries. These emulsions may be broken by adding a suitable demulsifier at the proper concentration with the minimum stability. In this study, different surfactant demulsifiers including hydrophilic and hydrophobic groups with different HLB values (KENON 20, KENON 10, KENON 4, KENON 2, MBG, CTAB, SDS, Span 80, Span 60, PEG, polyamide, polyacrylamide and an EO/PO block copolymer of dodecan-1-ol) were employed for the destabilization and separation of gas condensate droplets in water emulsion. The results revealed that the demulsifiers KENON 2, polyamide, EO/PO block copolymer of dodecan-1-ol and polyacrylamide were effective materials for the destabilization of the emulsion. Additionally, the addition of these demulsifiers leads to growing gas condensate droplets from 5 to about 25 μm showing a very good growth. Moreover, the results showed that the maximum separation of gas condensate from the emulsion were obtained using polyamide and dodecan-1-ol which was approximately 45 vol.% after 2 h at a concentration of 300 ppm of demulsifiers. Furthermore, the maximum gas condensate separation of 70 vol.% was obtained using dodecan-1-ol and KENON 2 after 24 h.

Modern detergents are typically appreciated for their cleaning performance rather than foaming characteristics. The aim of the current study was to compare the foaming and cleaning abilities of liquid detergents, built from a combination of surfactants, to be applied for household laundry purpose. A total of eighteen different liquid detergent formulations containing mixtures of important anionic, nonionic surfactants, and other additives were prepared. The first set of nine new detergent formulations (S1) was prepared using the surfactants sodium lauryl sulfate (SLS), Tween-20 and Tween-80. Another set of nine new detergent formulations (S2) was prepared using surfactants SLS, Triton X-100 and alkyl polyglucoside (APG). The impact of water quality (RO, hypersaline or hard water) on the foam properties of the detergent formulation sets (S1 and S2) was systematically examined. The second set of detergent formulations (S2) showed a better performance in terms of foamability and foam stability, regardless of the water quality. Also, the surface tension of the detergent formulation set S2 was found to be lower and it showed a higher detergency for both cotton and woolen fabrics. The detergency of the formulation no S2.9 (in set S2) was the maximum amongst all the detergent formulations. The surface morphology of the cotton and woolen fabrics, washed with liquid detergent formulation no S2.9, displayed the removal of oily soil and grease from the surface of the fabrics, without affecting the quality of the fabrics.