Synthesis and Properties of a Novel Gemini Surfactant with Bis-piperidinium

Abstract

A novel cationic Gemini surfactant with bis-piperidinium and benzene ring (C₁₀-CGP) was synthesized by aniline, epichlorohydrin and 1-bromodecane in three steps. The structure of C₁₀-CGP was characterized by mass spectroscopy (MS) and nuclear magnetic resonance (¹H NMR). The critical micelle concentration (CMC) and the corresponding surface tension (γ _CMC) of C₁₀-CGP were measured from 298 K to 313 K and the thermodynamic parameters of the micellization were calculated. The results showed that the critical micelle concentration (CMC) and γ_CMC were 0.976 × 10⁻³ mol · L⁻¹ and 28.93 mN · m⁻¹ at 298 K, respectively. With the temperature increase, the CMC increased, the maximum surface adsorption capacity (Γ _max) decreased, the γ _CMC decreased and the minimum molecule area (A _min) increased. The free energy of the system during the micelle formation was negative. When the Gemini surfactant was used as an asphalt emulsifier, C₁₀-CGP exhibited good a emulsifying ability. C₁₀-CGP is a slow-set asphalt emulsifier.