Abstract: A cationic Gemini surfactant containing bis-piperidinium group (hereinafter refers to as C₁₀-CGP) was synthesized via three steps with aniline,epichlorohydrin,piperidine and 1-bromodecane as starting materials.The product was characterized by FT-IR,MS and ¹H NMR.The Krafft point and emulsifying power of the product as well as performance of emulsified asphalt prepared with the product were examined.The critical micelle concentration (cmc) and corresponding surface tension (γ_cmc) of C₁₀-CGP were measured at temperature range from 25 ℃ to 40 ℃ and thermodynamic parameters of the micellization were calculated.Results show that the Krafft point of C₁₀-CGP is below 0 ℃;stable time of emulsified liquid achieves 532 s;the cmc and γ_cmc at 25 ℃ is 0.976×10^-3 mol/L and 28.93 mN/m respectively.With the increase of temperature,the cmc increases,while the γ_cmc decreases,the maximum surface adsorption capacity (Γ_max) decreases and the minimum molecule sectional area (A_min) increases.Emulsified asphalt test shows that C₁₀-CGP is a slow-crack type asphalt emulsifier;storage stability of the emulsified asphalt is good and particle size distribution of the emulsified asphalt is narrow.

Key words: Gemini surfactant, bis-piperidinium, surface tension, synthesis, asphalt emulsifier