Synthesis And Properties Of Silicon-containing Surface Active Ionic Liquids

In recent years,surface active ionic liquids（SAILs）with excellent physical and chemical properties have been a research hotspot in the fields of ionic liquids and surfactants.However,what species of SAILs are researched mostly are long-chain alkyl ionic liquids at present,which have relatively few kinds and are applied restrictedly.Silicone has excellent hydrophobicity and surface activities,and the ionic liquids with excellent surface properties obtained by introducing organic silicone as an hydrophobic group have been reported.However,the systematic research of synthesis and properties of silicon-containing surface active ionic liquids is still lacking.The N-alkyl imidazole were synthesized by imidazole,acrylonitrile and bromoalkanes as starting materials,and the process conditions of quaternization reaction,which was the main control process of the whole reaction,were optimized.The structures of intermediate were characterized by IR and 1HNMR.The silicon-containing surface active ionic liquids [MTMSiC_nim]Cl（n=5,6,8,10）were prepared with N-alkyl imidazole and chloromethyltrimethylsilane as raw material via microwave synthesis,and the structures of products were characterized by IR and 1HNMR.By comparing microwave method with conventional heating synthesis method,the reaction time was shortened and the yield of products was increased.The thermal stabilities,surface activities and foaming properties of [MTMSiC_nim]Cl were measured by thermal gravimetric analysis,surface tension and oscillation method.The results showed that [MTMSiC_nim]Cl have higher surface activity compared with long-chain alkyl imidazolium ionic liquids with similar structure,but the thermal stability was decreased slightly.The foaming power was related with solution concentration and the carbon number of the side chain alkyl,and the foam stabilities of [MTMSiC_nim]Cl were not good enough.Finally,the application of silicon-containing surface active ionic liquids in enhanced oil recovery was explored.It was found that the compound system of [MTMSiC₁₀im]Cl and AESO could reduce the interfacial tension of oil-water to 10^-2 mN/m,so silicon-containing surface active ionic liquids have a broad application prospect.