Fu Han

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.

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.

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.