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.