Synthesis and properties of a branched short-alkyl polyoxyethylene ether alcohol sulfate surfactant

Interaction, Surface Activity, and Application of Mixed Systems of Alcohol Ether Sulfate Anionic Surfactants with Multiple Ethylene Oxide Groups and Gemini Quaternary Ammonium Surfactant

The surface activities and application properties for the mixtures of cationic surfactants tetramethylene-1,4-bis[N,N-bis(hydroxypropyl)-hexa/decyloxypropylammonium] bromide (GC10-P) and tetramethylene-1,4-bis[N,N-bis(hydroxyethyl)-hexa/decyloxypropylammonium] bromide (GC10-E) and anionic surfactant isomeric sodium fatty alcohol ether sulfates (iso-AE9S) were investigated using both the tensiometry and the conductometry. The interaction parameters and thermodynamic micellization parameters of GC10-P/iso-AE9S and GC10-E/iso-AE9S mixtures were evaluated by Clint-Rubingh and Motomura theoretical models. When the mole fraction of α1 for GC10-P/iso-AE9S mixed system was 0.2, the critical micelle concentration (CMC) reached a minimum of 1.61 × 10-4 mol/L, and the minimum critical micelle concentration of the GC10-E/iso-AE9S mixed system is 2.67 × 10-5 mol/L at α1 = 0.6. The CMC value of the mixed system is 1-2 orders of magnitude lower than that of any single component. The results indicate that the synergistic effects of the investigated mixed systems (evaluated by βm) are in order of GC10-P/iso-AE9S < GC10-E/iso-AE9S, with maximum βm values of -17.98 and -9.78, respectively. The change in zeta potential indicates that the poly(ethylene oxide) chain has weakened the charge density of the hydrophilic headgroup of the anionic surfactant. The interfacial tension at the oil-water interface in the mixed system of anionic/cationic surfactants is lower than that of any single component, exhibiting a higher interfacial activity. The mixed system exhibits a decreased contact angle and superior wetting ability over any single component, and it also enhances foam performance, emulsification performance, and degreasing performance.

Study on the Synthesis, Surface Activity, and Self-Assembly Behavior of Anionic Non-Ionic Gemini Surfactants

The use of surfactants in oil recovery can effectively improve crude oil recovery rate. Due to the enhanced salt and temperature resistance of surfactant molecules by non-ionic chain segments, anionic groups have good emulsifying stability. Currently, there are many studies on anionic non-ionic surfactants for oil recovery in China, but there is relatively little systematic research on introducing EOs into hydrophobic alkyl chains, especially on their self-assembly behavior. This article proposes a simple and effective synthesis method, using 3-aminopropane sulfonic acid, fatty alcohol polyoxyethylene ether, and epichlorohydrin as raw materials, to insert EO into hydrophobic alkyl chains and synthesize a series of new anionic non-ionic Gemini surfactants (CnEO-5, n = 8, 12, 16). The surface activity, thermodynamic properties, and self-assembly behavior of these surfactants were systematically studied through surface tension, conductivity, steady-state fluorescence probes, transmission electron microscopy, and molecular dynamics simulations. The surface tension test results show that CnEO-5 has high surface activity and is higher than traditional single chain surfactants and structurally similar anionic non-ionic Gemini surfactants. Additionally, thermodynamic parameters (e.g., ΔG°mic ΔH°mic ΔS°mic et al. indicate that CnEO-5 molecules are exothermic and spontaneous during the micellization process. DLS, p-values, and TEM results indicate that anionic non-ionic Gemini surfactants with shorter hydrophobic chains (such as C8EO-5) tend to form larger vesicles in aqueous solutions, which are formed in a tail to tail and staggered manner; Negative non-ionic Gemini surfactants with longer hydrophobic chains (such as C12EO-5, C16EO-5) tend to form small micelles. The test results indicate that CnEO-5 anionic non-ionic Gemini surfactants have certain application prospects in improving crude oil recovery.

Effect of Oxyethylene Groups of Fatty Alcohol Polyoxyethylene Ether Sodium Sulfates on Equilibrium and Dynamic Surface Tension in Relation to Wetting Properties

The effect of hydrophilic chain of surfactants fatty alcohol polyoxyethylene ether sodium sulphates (AEnS, n = 2, 3, 7) on surface properties and wetting properties was investigated by the measurement of equilibrium surface tension, dynamic surface tension and dynamic contact angle. The fatty alcohol polyoxyethylene ether sodium sulphates with different head group sizes were used. From the results of equilibrium surface tension measurements, we could obtain the critical micellisation concentration, adsorption efficiency, maximum surface excess concentration and Langmuir equilibrium adsorption constant at air/liquid interface. The dynamic surface tension results showed that the adsorption of aqueous solutions at the air/liquid interface follows a mixed-diffusion kinetic adsorption mechanism. In conclusion, for both studied surfactant, the longer the oxyethylene chains, the higher the maximum rate of surface tension reduction, the higher the diffusivity and wetting properties in terms of contact angle.

Performance Study of Narrow-distribution Aliphatic Alcohol Polyoxyethylene Ether Phosphates with Large EO Addition Number

In this paper, three kinds of aliphatic alcohol polyoxyethylene ethers (AEO) with different molecular weight distribution were used as raw materials, and aliphatic alcohol polyoxyethylene ether phosphate (AEP) was obtained by P2O5 process. FT-IR and 31P-NMR were used to characterize the structure of the product, confirming the formation of the product. HPLC-ESI was used to probe the molecular weight distribution of the sample. The surface activity, wetting properties and application properties of the samples were measured. Wetting and permeability were found to increase with decreasing EO addition, and N-AE7P is optimal, which is related to the spatial structure of the molecule. The surface activity, washing performance and foaming properties of C-AE9P are better as that of the other investigated compounds because of the synergistic effect between the complex components.

Synthesis of Fatty Alcohol Ether Carboxylic Ester Surfactant and its Performance in an Anionic/Non-Ionic Mixed System

A salt-type fatty alcohol ether carboxylic ester (AECE-Na) surfactant with both anionic and non-ionic characteristics was synthesised using a fatty alcohol ether (AEO) and succinic anhydride. Compared with traditional synthetic methods, neither irritating substances (chloroacetic acid and chloroacetate) nor precious metals (Pt and Pd) were used in the synthesis, which is a simple, economic, and green method. FT-IR and 1H NMR spectroscopies and MALDI TOF mass spectrometry were used to prove the molecular structure of the target product AECE-Na. In addition, the surface activities, intermolecular interactions, application properties, and aggregation behaviours of the individual systems (AEO and AECE-Na) and the anionic/non-ionic mixed system (AECE-Na/AEO) were investigated. The results showed that AECE-Na/AEO exhibits synergistic effects in terms of surface tension reduction efficiency, wetting, emulsification, foaming, and detergency compared with the individual systems.

Wettability of Phosphonium Benzene Sulfonate on Parafilm

The wettability of phosphonium benzene sulfonate on parafilm has been investigated by means of dynamic contact angle measurement. Based on the surface tension data, the spreading coefficient, adhesion tension (γlg cosθ), and adhesion work (WA) were further analyzed. It was revealed that the surface tension and contact angle decreased with the increase in concentration, and remained constant when the concentration was higher than the critical micelle concentration (CMC). Furthermore, the spreading coefficient increased with increase in concentration then stays unchanged. In the studied concentration range, the value of spreading coefficient is negative, indicating that it cannot rapidly spread the surfactant on the parafilm surface to an uniform film. The measurements show a linear relationship between the adhesion tension γlg cosθ and the surface tension in the concentration range of 2 × 10−6 mol L−1 to 1 × 10−4 mol L−1. The adsorbed amount of surfactant molecules at the parafilm-solution interface is lower than that at the gas-liquid interface. The value of WA was initially decreased then increased as the concentration was increasing and reaches a minimum value at the concentration near the CMC.

Silica Modified by Alcohol Polyoxyethylene Ether and Silane Coupling Agent Together to Achieve High Performance Rubber Composites Using the Latex Compounding Method

The study of preparing silica/rubber composites used in tires with low rolling resistance in an energy-saving method is fast-growing. In this study, a novel strategy is proposed, in which silica was modified by combing alcohol polyoxyethylene ether (AEO) and 3-mercaptopropyltriethoxysilane (K-MEPTS) for preparing silica/natural rubber (NR) master batches. A thermal gravimetric analyzer and Raman spectroscopy results indicated that both AEO and K-MEPTS could be grafted on to the silica surface, and AEO has a chance to shield the mercaptopropyl group on K-MEPTS. Silica modified by AEO and K-MEPTS together was completely co-coagulated with the rubber in preparing silica/NR composites using the latex compounding method with the help of the interaction between AEO and K-MEPTS. The performance of composites prepared by silica/NR master batches was investigated by a rubber process analyzer (RPA), transmission electron microscopy (TEM) and a tensile tester. These results demonstrate that AEO forms a physical interface between silica and rubber, resulting in good silica dispersion in the matrix. K-MEPTS forms a chemical interface between silica and rubber, enhancing the reinforcing effect of silica and reducing the mutual friction between silica particles. In summary, using a proper combination of AEO and K-MEPTS is a user-friendly approach for preparing silica/NR composites with excellent performance.