Synthesis and Surface Properties of Novel Gemini Imidazolium Surfactants. Issue 6 (31st July 2014)

• Record Type: Journal Article
• Authors: Wang, Liyan; Liu, Jia; Huo, Shichao; Deng, Qigang; Yan, Tie; Ding, Limin; Zhang, Chao; Meng, Lingwei; Lu, Qiangna
• Is Part Of: Journal of surfactants and detergents. Volume 17:Issue 6(2014)
• Page Start: 1107
• Page End: 1116
• Publication Date: 2014-07-31
• Subjects: Imidazolium -- Gemini surfactant -- Synthesis -- Surface properties -- Characterization; Surface active agents -- Periodicals; Detergents -- Periodicals; 668.1
• DOI: 10.1007/s11743-014-1615-0
• Languages: English
• ISSNs: 1097-3958

Abstract

Abstract: Five new Gemini imidazolium surfactants were synthesized from imidazole and 1‐bromoalkane (C8, C10, C12, C14, C16 ) to get 1‐alkylimidazole, which was further reacted with 1, 3‐dichloropropan‐2‐ol to form the surfactant molecule, 1, 1′‐(propane‐1, 3‐diyl‐2‐ol) bis(3‐alkyl‐1 H ‐imidazol‐3‐ium) chloride. The structures of the five new surfactants and intermediates were characterized by 1 H‐NMR, 13 C‐NMR and IR spectra. Thermal properties of the five new surfactants were studied with thermogravimetric analysis and differential scanning calorimetry, the five new surfactants showed a transition from a crystalline phase to a thermotropic liquid–crystalline phase at around ca. 100 °C, which transformed to an isotropic liquid phase at around ca. 165 °C. The five new surfactants critical micelle concentrations (CMC) in the aqueous solutions were determined by surface tension and electrical conductivity methods. The surface tension measurements provided a series of parameters, including critical micelle concentration (CMC), surface tension at the CMC ( γ CMC ), adsorption efficiency ( pC 20 ), and effectiveness of surface tension reduction (πCMC ). In addition, with application of the Gibbs adsorption isotherm, maximum surface excess concentration (Γmax ) and minimum surface area/molecule (Amin ) at the air–water interface were obtained. The parameters β (degree of counterion binding to micelles), ΔGads θ (Gibbs free energy of adsorption), and ΔGmic θ (Gibbs free energy change of micellization) were also derived. The results indicated that the five new Gemini surfactants exhibited very low CMC and a good efficiency in lowering the surface tension of water. The foamability and foam stability of the five new surfactants were also examined at different CMC.