Dynamic　surface　tension　(DST)　of　the　mixed　aqueous　solution　of　opposite-charged　gemini　surfactants　C9pPHCNa　with　C-10-2-E-2-C-10　center　dot　2Br　was　measured　using　the　maximum　bubble　pressure　technique.　The　mole　fraction　of　C9pPHCNa　(alpha(1),　on　a　surfactant-only　basis)　in　the　bulk　solution　was　from　1　to　0.6.　Plateaus　were　observed　in　the　DST　curves　of　the　mixtures　at　total　concentration　of　0.8　mmol　L-1　except　the　case　with　alpha(1),　=　0.6.　This　was　attributed　to　the　C-10-2-E-2-C-10(2+)/C9pHC(2-)　ion-pairs　with　high　surface　activity　adsorbing　significantly,　which　led　to　desorption　of　the　monomer　molecules　already　at　the　surface.　The　micelles　in　the　solution　also　affected　the　dynamic　adsorption　since　all　the　investigated　concentrations　of　mixed　systems　were　above　their　cmcs.　Dissociation　of　micelles　offered　both　the　monomers　and　the　ion-pairs　to　adsorb　at　the　surface,　resulting　in　the　DST　curve　moving　down　when　the　total　concentration　of　the　system　was　increased.　(c)　2006　Elsevier　B.V.　All　rights　reserved.