zeta电位与膜电导的关系以及具体的测定方法

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1、JournalofMembraneScience226(2003)227236Determiningtheζ-potentialofplanemembranesfromtangentialstreamingpotentialmeasurements:effectofthemembranebodyconductanceP.Fievet∗,M.Sba¨ı,A.Szymczyk,A.VidonneLaboratoiredeChimiedesMatériauxetInterfaces,16RoutedeGray,

2、25030BesançonCedex,FranceReceived28April2003;receivedinrevisedform5September2003;accepted11September2003AbstractTheζ-potentialisanimportantandreliableindicatorofthesurfacechargeofmembranesanditsknowledgeisessentialforthedesignandoperationofmembraneprocess

3、es.Thestreamingpotentialremainsthemostwidelyusedtechniquefordeterminingtheζ-potentialofmembranes.Inthecaseofasymmetricorcompositemembranes,theζ-potentialisnowfrequentlydeterminedfromtangentialflowstreamingpotentialmeasurements.However,theinterpretationofda

4、taintermsofζ-potentialisusuallycarriedoutbydoingtheimplicitassumptionofnon-conductingsubstrates.Inthispaper,weinvestigatetheelectrokineticpropertiesofaceramicmembraneclosetotheNFrange,theporousstructureofwhichaffectsthestreamingpotentialbecausestreamingan

5、dconductioncurrentsinvolvedinthestreamingpotentialprocessdonotflowthroughidenticalpaths(thestreamingcurrentflowsonlythroughtheslitchannelformedbythetwomembranesamplesfacingeachotherwhereasanon-negligiblepartoftheconductioncurrentislikelytoflowthroughthemembr

6、aneporesfilledwithelectrolytesolution).Inthiscase,theso-calledFairbrotherandMastin(FM)procedureaccountingforthesurfaceconductancetocorrecttheHelmholtzSmoluchowski(HS)relationisnotsuitableandleadstoanerroneousζ-potential.Thecorrectζ-potentialvalueisdetermin

7、edfromanextrapolationmethodforwhichasetofmeasurementswithvariouschannelheightsisrequired.Averygoodagreementisobtainedwithζ-potentialvaluesdeducedfromconsecutivestreamingpotentialandtotalconductancemeasurements.Thecontributionofthemembranebodytothetotalcon

8、ductivityofthemembrane/channel/membranesystemappearstobeindependentofthepHofsolution,probablyduetothefactthattheelectricconductiontakesplacethroughthemembraneporousbodyinsideathicklayerdominatedbythesupportlayerwhic