The Efects Of Gemini Surfactant’s Surface Activity Form Inorganic Salt

The changes of surface tension and the critical micelleconcentration of dodecyltrimethylammonium bromide（DTAB）,N,N,N’N’-tetramethyl-N,N’-di（dodecyl）ethylenediaminebromide (C₁₂-2-C₁₂) and N,N,N’,N’-tetramethyl-N,N’-di（dodecylamidemethyl） ethylenediamine chloride（HTF-3A-X） wereinvestigated respectively by using the method of drop volume,adding NaF, NaCl, NaBr, KI, Na₂SO₄, at the same temperature. TheCMC of DTAB decreased remarkably in NaF, NaCl, NaBr solutionsrespectively. Compared with DTAB, the impact of NaF, NaCl, NaBrfor the CMC of C₁₂-2-C₁₂and HTF-3A-X was relatively small, but Geminisurfactant C₁₂-2-C₁₂and HTF-3A-X solutions having KI within it wasturbid, only the temperature increased to61℃and56℃,turbidity was disapeared. Both of the above Gemini surfactantscompared, the impact of salt for the CMC of HTF-3A-X was relativelystronger, sediments were formed when HTF-3A-X was added to Na₂SO₄（0.01mol·L-1） solution,even the temperature reached to boilingtemperature, the mixed solution was still turbid.