Sulfonic gemini surfactants: Synthesis, properties and applications as novel air entraining agents for concrete

Abstract The development of high performance air entraining agents for concrete is of great importance. In this work, sulfonic gemini surfactants have been utilized as high performance air entraining agents for the first time. Six sulfonic gemini surfactants with different hydrophobic chains and spacer groups were designed and synthesized. The surface tensions and foam properties of their aqueous solutions were tested. Using them as the air entraining agents, the air contents and air-void parameters of the cement mortars were also tested. The properties of different geminis and their single-chained analogue were fully compared and discussed. The results show that the geminis have higher surface activity, foamability, foam stability and air entraining performance compared with their single-chained analogue, and the gemini with 12-carbon hydrophobic chains and 2-carbon alkyl spacer has highest performance.