EN 14210-2003 en Surface active agents Determination of interfacial tension of solutions of surface active agents by the stirrup or ring method《表面活性剂 用镫形法或圆环法测定表面活性剂溶液的表面张力》.pdf

1、BRITISH STANDARD BS EN 14210:2003 Surface active agents Determination of interfacial tension of solutions of surface active agents by the stirrup or ring method The European Standard EN 14210:2003 has the status of a British Standard ICS 71.100.40 BS EN 14210:2003 This British Standard was published

2、 under the authority of the Standards Policy and Strategy Committee on 19 January 2004 BSI 19 January 2004 ISBN 0 580 43294 7 National foreword This British Standard is the official English language version of EN 14210:2003. The UK participation in its preparation was entrusted to Technical Committe

3、e CII/34, Methods of test for surface active agents, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this d

4、ocument may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contra

5、ct. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for

6、 change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 13 and a back cover. The BSI copyright notice displayed in

7、this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN14210 December2003 ICS71.100.40 Englishversion SurfaceactiveagentsDeterminationofinterfacialtensionof solutionsofsurfaceactiveagentsby

8、thestirruporringmethod AgentsdesurfaceDterminationdelatensioninterfaciale dessolutiondagentsdesurfaceparlamthodelanneau oultrier GrenzflchenaktiveStoffeBestimmungder GrenzflchenspannungvongrenzflchenaktivenLsungen mittelsBgeloderRingverfahren ThisEuropeanStandardwasapprovedbyCENon1October2003. CENme

9、mbersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmemb

10、er. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodiesofAustria,Belg

11、ium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Hungary,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,Slovakia,Spain,Sweden,SwitzerlandandUn ited Kingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeS

12、tassart,36B1050Brussels 2003CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN14210:2003EEN14210:2003(E) 2 Contents page Foreword3 1 Scope 4 2 Principle4 3 Apparatus .4 4 Preparationofapparatus 7 5 Procedure .7 6 Expressionofresults . .8 7 Precision.1

13、2 8 Testreport . .12 Bibliography 13EN14210:2003(E) 3 Foreword ThisdocumentEN14210:2003hasbeenpreparedbyTechnicalCommitteeCEN/TC276“Surfaceactiveagents”, thesecretariatofwhichisheldbyAFNOR. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublicationofanidenticaltextor byendorsem

14、ent,atthelatestbyJune 2004,andconflictingnationalstandardsshallbewithdrawnatthelatestby June2004. ThisdocumentincludesaBibliography. AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsofthefollowing countriesareboundtoimplementthisEuropeanStandard:Austria,Belgium,CzechRepu

15、blic,Denmark,Finland, France,Germany,Greece,Hungary,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal, Slovakia,Spain,Sweden,SwitzerlandandtheUnitedKingdom.EN14210:2003(E) 4 1Scope ThisEuropeanStandardspecifiestestmethodsforthedeterminationofinterfacialtensionintherangefrom 4mN/mto5

16、0mN/mbetweentwoimmiscibleliquidswhichcanalsobefreefromsurfaceactiveagents. Itisparticularlysuitablefordeterminingtheinterfacialtensionbetweenwateroraqueoussolutionsandorganic liquidswhichareimmisciblewithwater. 2Principle Themaximumforce, F,necessarytopullortoforceastirruporringoflength, l,outofthei

17、nterfacebetweentwo liquidsinthedirectionofthenonaqueousphaseismeasured.Theinterfacialtension, ,isobtainedbycalculation wherethefollowingapproximateequation(1)servesasbase: l F 2 = g (1) 3Apparatus 3.1Tensiometer 3.1.1 General Thetensiometershallbedesignedforusewithastirruporringandshallconsistessent

18、iallyofthepartsspecified in3.1.2and3.1.3. 3.1.2 Dynamometer(e.g.torsionbalanceorinductiveforcetransducer),capableforreadingofftheforcetothe nearest0,1mN/movertheeffectivelengthofthestirruporring. 3.1.3 Supportforthemeasuringvessel ,consistingofahorizontalplatformwhichcanbemovedverticallyup anddown,e

19、.g.withtheaidofaprecisiondrive. 3.2Stirrup Thestirrupshallconsistofplatinum/iridiumwirewithatestwirediameterof0,1mmandalengthof20mm to40mm.Thelengthofthetwobranchesshallbeabout20mm.Twosmallplatinumballscanbeattachedtothe lowerendsofthebranchesascounterweightsor,alternatively,thelowerendsofthebranche

20、scanbejoinedbya platinumwire(seeFigure1asanexample).EN14210:2003(E) 5 Dimensionsinmillimetres Figure1Stirrupformeasuringinterfacialtension NOTE ThestirrupspecifiedinEN14370formeasuringthesurfacetensionisidenticalwiththatoneshowninFigure1, exceptforthelengthsofthemeasuringwireandthebranches. 3.3Ring

21、Theringshallconsistofaplatinumorplatinum/iridiumwirewithathicknesslessthanorequalto0,4mmanda meancircumferenceof60mm.Bymeansofawirestirrup,itshallbeattachedinahorizontalpositiontoametal rodformingthelinktothetensiometer(seeFigure2asanexample).EN14210:2003(E) 6 Dimensionsinmillimetres Key 1 Metalrod

22、2 Wireloop 3R i n g Figure2Ringformeasuringinterfacialtension NOTE TheringspecifiedinEN14370formeasuringthesurfacetensionisidenticalwiththatoneshowninFigure2. 3.4Sample vessel Thesamplevesselfortheliquidundertestshallbeaglassvesselwhichissuitableforuseinathermostat.Itshall haveasufficientcapacityfor

23、theliquidwhich,ifnecessary,shallbeprotectedfromevaporation.Itshallbe constructedsuchthatthetemperatureofthegasphaseabovetheliquidcanalsobekeptconstantbythermostat. Thereisnoneedtouseathermostatformeasurementatroomtemperature.Thesamplevesselshallconsistofa cylindricalglasscontainerwithaninternaldiame

24、terofatleast45mmforusewiththeringmethodorstirrup method. NOTE Ifavesseloflessthan45mmdiameterneedstobeused(forexample,ifonlysmallamountsofsampleare available),walleffectscancauseanerrorintheinterfacialtensionmeasurement.Themagnitudeofthiserrordependsonthe distancebetweenthewallofthevesselandtheedgeo

25、ftheringorstirrup.EN14210:2003(E) 7 4 Preparationofapparatus 4.1Cleaning Cleantheglassvesselscarefully,firstbythoroughpreliminarycleaningusingasuitablesolvent,forexample propan2olorpropanone.Thenrinsethemrepeatedlywithfreshlydoubledistilledwateranddrythem.Cleanand rinsethestirrupsorringsinthesameman

26、ner,andthenheatthembrieflytoincandescenceinamethanolor ethanolflame(thelattermaybepreferredsinceithasalowvapourpressureandhigherflashpoint),preferablya nonluminousnaturalgasflame,ensuringtheyareonlyheatedtoredheatandnevertowhiteheat. NOTE Shouldthestirrupsorringsbecomecontaminatedwithresidues,forexa

27、mplefromsiliconesorcationicsurface activeagents,itcanbepreferabletocleanwithasulfochromicacidmixtureorasspecifiedinISO6889. 4.2Measurement preparation Doubledistilledwaterorwaterofequivalentpurityshallbeusedtoprepareanyaqueoussolutionrequiredforthe test. Thetemperatureoftheliquidsshallbekeptconstant

28、tothenearest 0,5 Cduringthemeasurement.The measurementtemperaturechosenshallbeanappropriateonefortheobjectiveofaparticulartest.Measurementsat roomtemperaturepresentthefewestproblems. Theinterfacialtensionchangeswithtimeandcanbeaffectedbythechemicalnatureofasurfaceactiveagent,its concentration,whethe

29、ritisdissolvedintheupperorlowerphase,itsadsorptivecapacityanditsadsorptionrate duringthechange.Soitisnotpossibletospecifyanappropriatetimeforstartingthemeasurements.Therefore, severalmeasurementsoftheinterfacialtensionasafunctionoftimeand,consequently,oftheageoftheinterface shallbeperformed.Afterati

30、mewhichischaracteristicforeverysystem,nofurtherchangesareobservedinthe interfacialtensionsinceanequilibriumstateisestablished.Itisadvantageoustousecommerciallyavailable, automatictensiometerstocarryoutsuchmeasurements. Interfacialsystemsareextremelysensitivetocontaminants.Forthisreason,noworkinvolvi

31、ngvolatilesubstances shallbecarriedoutinthemeasurementroomandtheapparatusshallbeprotectedbyanenclosureofthetypeused forbalances.Thisprecautionalsofacilitatesmaintenanceofaconstanttemperature. 5Procedure 5.1General Twomethodsofmeasurementaredescribedin5.2and5.3.Intherelativestirruporringmethod(see5.2

32、),the measuredvalueiscomparedwiththecorrespondingvaluedeterminedonasystemoftwoliquidswithsimilar densitiestothoseoftheliquidsundertestdensitiesandknowninterfacialtension.Intheabsolutering method(5.3),accountistakenofafactorfortheapparatusdeterminedusinganadjustmentweightandaZuidema andWaterscorrecti

33、onfactor1whendeterminingtheinterfacialtension.TheZuidemaandWatersfactorisbased onthecorrectiondeterminedempiricallybyHarkinsandJordan2formeasurementsmadebytheringmethod. Differentmeasurementproceduresareadopted,dependingonwhetherthedensityoftheaqueousphaseisgreater orlessthanthatofthenonaqueousphase

34、. 5.2 Relativestirruporringmethod 5.2.1Method A Method Aisamethodforsystemsinwhichthedensityoftheaqueousphaseisgreaterthanthatofthe nonaqueousphase. Useapipettetotransferanamountoftheaqueousphaseabout15mmdeeptothemeasuringapparatusholding thetipofthepipetteagainstthevesselwall,avoidingbubbles.Checkt

35、hatthetestwireofthestirruporringis horizontalbyusingthesurfaceoftheliquidasamirrorwhenthestirruporringisjustaboveit.Thenslowlyraise theplatformandthemeasurementvesseluntilthestirruptestwireorringisimmersedintheaqueousphase.ThenEN14210:2003(E) 8 addaroughly15mmdeeplayerofthenonaqueousphase,againavoid

36、ingbubbles,andleaveforatleast5min (seeclause3)toallowtheliquidstobecomemutuallysaturated. Thenrepeatedlylowertheplatformandraiseitagainuntilthefilmalmostbreaks.Readoffthemaximumvalue, W 2 , obtainedonthetensiometereverytime.Readoffthevalue W 1 whenthestirruptestwireorringis immersedwithoutafilminthe

37、upperphasetothesameextentaswhenmeasuring W 2 .Thisgivesthedifference D W= W 2 W 1 .Ifthesameprocedureisusedforasystemoftwoliquidswithsimilardensitiesandknowninterfacial tension, 0 ,(e.g.avaluefromtheliterature), D W 0 isobtained. 5.2.2Method B MethodBisamethodforsystemsinwhichthedensityoftheaqueousp

38、haseislessthanthatofthenonaqueous phase. Pourboththephasesintothemeasurementvesseltoadepthof15mmineachcase,avoidingbubbles.After checkingthatthestirruporringishorizontal(asin5.2.1),raisetheplatformandmeasuringvesseluntilthestirrupor ringisimmersedintheupperphaseandleaveforatleast5min(seeclause4)toal

39、lowtheliquidstobecomemutually saturated.Thenraisetheplatformfurtheruntilthestirruporringpassesthroughtheinterfaceandafterthatraiseand loweritagainuntilthefilmalmostbreaks.Readoffthemaximumvalue, W 2 ,obtainedineachcase.Readoff W 1 when thestirrupmeasuringwireorringisimmersedwithoutafilminthelowerpha

40、setothesameextentasinthe measurementof W 2 .Thisyieldsthedifference D W= W 2 W 1 .Thendetermine D W 0 asin5.2.1. 5.3 Absoluteringmethod Calibratethetensiometerbyaddingaweightwithaknownmass, m,ofabout0,5gtotheringandregisterthe resultantreading, A 1 .Determinethemaximumvalue, W 2 ,fortheformationofth

41、efilmandthevalue, W 1 ,withoutafilm andtakethedifference, D W= W 2 W 1 ,asintherelativemethod(5.2.1or5.2.2). 6 Expressionofresults 6.1General Inviewofthemassofthestirruporringandofthefactthatthemagnitudeoftheforcesencounteredislow,itis advisabletoexpressallthequantitiesincentimetres,grams,seconds(cg

42、sunits),e.g. g=981cm/s 2 , ing/cm 3 andwirelengthandwirethicknessincentimetres.ThiswillgivetheinterfacialtensionintheSIunitmillinewtonsper meter(1mN/m=1dyn/cm). 6.2 Relativestirruporringmethod Therequiredinterfacialtension, g ,isgivenbyequation(2): o o W W g g = (2) where g o isthevaluegiveninthelit

43、eraturefortheinterfacialtensionofthereferencesystem; W W 0 see5.2.1or5.2.2.EN14210:2003(E) 9 6.3 Absoluteringmethod Determinethefactor, fortheapparatususingequation(3): 1 2 A A = (3) where D g m A p 2 2 = (4) where m isthemassoftheadditionalmass; g istheaccelerationduetogravity; D isthemeanringdiameter; A 1 isthereadingonthe