Yawen Zhou

Lauryl Trimethyl Ammoniums with New Type Counteranions

Abstract The interfacial properties of a new family of lauryl trimethyl ammonium salts of the general formula CH3(CH2)11N+(CH3)3X− (X = CH3OCOO, HCOO, CH3COO, CH3CHOHCOO) were studied. The physicochemical parameters of these quaternary ammonium salts were discussed. The effect of the counteranion on the behavior of these surfactants was analyzed.

A Surface Rheological Study of a Glucosamide-Based Trisiloxane Gemini Surfactant at the Air/Water Interface

The dilational viscoelastic properties of a glucosamide-based trisiloxane gemini surfactant at the air/water interface were investigated. Aqueous solutions of the glucosamide-based trisiloxane gemini surfactant were spread onto a pendant drop and the dynamic surface tensions were measured by means of axisymmetric drop shape analysis. The surface dilatational elasticity, viscosity, and phase angle of the adsorption monolayer were also determined by the oscillating drop technique. The influences of frequency and concentration on the surface dilational properties were expounded. It is showed that the surface dilational modulus and elastic modulus increased with the increase of frequency, the viscous modulus was complex, while the phase angle decreased with the increase of frequency. Surface dilational modulus, elastic modulus, and viscous modulus passed through the maximum with the increase of bulk concentration and the phase angle increased with the increase of concentration.

A Surface Rheological Study of Silwet L-77 Surfactant at the Air/Water Interface

The dilational viscoelastic properties of Silwet L-77, a trisiloxane surfactant of the general formula (Me3SiO)2SiMe(CH2)3(OCH2CH2)7.5OH, at the air/water interface were investigated. Aqueous solutions of Silwet L-77 were spread onto a pendant drop and the dynamic surface tensions were measured by means of axisymmetric drop shape analysis. The surface dilatational elasticity, viscosity, and phase angle of the adsorption monolayer were also determined using the oscillating drop technique. The influences of frequency and concentration on the surface dilational properties were expounded. It is shown that the surface dilational modulus and elastic modulus increased with the increase of frequency, the viscous modulus was complex, while the phase angle decreased with the increase of frequency. Surface dilational modulus, elastic modulus, and viscous modulus passed through the maximum with the increase of bulk concentration and the phase angle increased with the increase of concentration.

Foam and Rheological Properties of a Kind of Extended Surfactants

Abstract The foam and rheological properties of four extended surfactants C12–14PmE2S (m = 0, 3, 5, and 8) of four different concentrations were investigated in this paper. The foam properties, including, foamability, foam stability, liquid carrying ability, foam drainage and foam morphology were characterized. The rheological measurements were carried out through frequency sweep in the oscillation mode. The foamability and foam stability decreased with increasing numbers of PO groups embedded in those surfactants. At the same concentration, the longer the PO chain of the surfactant molecule, the larger the liquid carrying capacity of the foam. The foaming number decreases as the time increases, and longer PO chains were associated with faster foam number decline. The rheological measurements show that those surfactant solutions are “liquid-like”. With increasing surfactant concentration, the viscous modulus of C12–14P8E2S increases gradually, whereas that of C12–14E2S decreases.

Aggregation behaviors of amine-oxide gemini surfactants

ABSTRACT The micellar aggregation of a series of gemini surfactants [N, N’-dimethyl-N, N’-bis(2-alkylamideethyl)-ethylenediamine oxide (alkyl = C11H23, C13H27, C15H31)] in aqueous media has been investigated. The results show that there is an excellent agreement among the critical micelle concentration (CMC) values obtained by surface tension and steady-state fluorescence methods. Because of the occurrence of self-coiling or the formation of pre-micellization, the CMC values, the I1/I3 values, and the micelle aggregation numbers (Nagg) at CMC (Nm) increase with the hydrophobic alkyl chain length increasing. Besides, vesicles are observed above the CMC for all these surfactants. GRAPHICAL ABSTRACT

Synthesis and Characterization of Saturated Cardanol Sulfonate Salt Gemini Surfactant

Abstract The synthesis, structural analysis and properties of saturated cardanol sulfonate salt Gemini surfactant (Gemini-SCSS) were described and compared with saturated cardanol sulfonate salt (SCSS). The structure was characterized by infrared spectra and proton nuclear magnetic resonance. Gemini-SCSS reduced the surface tension of water to a minimum value of approximately 35 – 37 mN m−1 with concentrations of (0.9 − 2.0) × 10−4 mol L−1 and displayed low foamability and high emulsification, which were better than those of SCSS. Finally, Gemini-SCSS and SCSS both demonstrated good resistance to acid, alkali, hard water.

Green Synthesis and Surface Properties of Acyl Glycine Surfactants Derived from Vegetable Oils

Abstract Oils from coconut, peanut, and soybean were reacted as acyl donors with sodium glycinate to synthesize acyl glycine surfactants. From these three oils a series of acyl glycines with different acyl chain lengths was obtained. The proportion of each component was consistent with the composition of fatty acids derived from the three vegetable oils. The surface properties of the corresponding sodium salts were determined. Sodium cocoyl glycinate, the sodium salt of acyl glycine from peanut oil, and the sodium salt of acyl glycine from soybean oil reduced the surface tension of water to 33.1, 31.6, and 33.4 mN · m−1, respectively, at corresponding critical micelle concentrations of 0.21, 0.057, and 0.05 mmol · L−1. The three acyl glycine surfactants exhibited favorable foam properties, good detergency, and good emulsifying properties.

Synthesis and Characterization of N-alkyl-N′-glucosylhexanediamine Surfactant

Abstract The synthesis and structural analysis of glucosamide surfactants of the general formula CnH2n+1NH(CH2)6NHCO(CHOH)4CH2OH (n = 8, 10, 12) were described, and the surface activity properties of the surfactants were studied, and the interfacial tensions between n-octane and the aqueous surfactant solution were measured. N-alkylhexanediamines were synthesized by the alkylation of the 1,6-hexanediamine with alkyl bromide. The glucosamide surfactants, N-alkyl-N′-glucosylhexanediamine (CnGA), were prepared by amidation of the precursor diamine with D-gluconic acid δ-lactone. They were structurally characterized by IR, 1H NMR and MS. They reduced the surface tension of water to approximately 28–33 mN · m−1 at concentration levels of (0.2–1.0) × 10−3 mol · L−1, and reduced the interfacial tensions between n-octane and the aqueous surfactant solution to approximately 1–2 mN · m−1 at concentration levels of (0.3–4.2) × 10−3 mol · L−1.

Synthesis and Properties of Sodium Mono-alkylamide Maleate Surfactants

Abstract The synthesis of a series of sodium mono-alkylamide maleate surfactants was described, and the surface activity properties of the surfactants were studied. The mono-alkylamide maleic acids were synthesized by amidation using primary aliphatic amine (lauryl, myristyl, cetyl) and maleic anhydride as starting material. They were structurally characterized by IR, 1H-NMR and MS. The sodium mono-alkylamide maleate surfactants were prepared by neutralization of the precursor mono-alkylamide maleic acids with sodium hydroxide. They reduced the surface tension of water to 32–34 mN · m–1 at concentration levels of 10–4–10–3 mol · L–1.