BS ISO 13099-1-2012 Colloidal systems Methods for zeta-potential determination Electroacoustic and electrokinetic phenomena《胶体系统 电动电势测定法 电声和动电现象》.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 13099-1:2012Colloidal systems Methods for zeta-potentialdeterminationPart 1: Electroacoustic and electrokineticphenomenaBS ISO 13099-1:2012 BRITISH STANDARDNational forewo

2、rdThis British Standard is the UK implementation of ISO 13099-1:2012. The UK participation in its preparation was entrusted to TechnicalCommittee LBI/37, Particle characterization including sieving. A list of organizations represented on this committee can be obtained on request to its secretary.Thi

3、s publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2012. Published by BSI Standards Limited 2012ISBN 978 0 580 70476 5 ICS 19.120 Compliance with a British Standard cannot confer i

4、mmunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2012.Amendments issued since publicationDate T e x t a f f e c t e dBS ISO 13099-1:2012 ISO 2012Colloidal systems Methods for zeta-potential determination

5、Part 1: Electroacoustic and electrokinetic phenomenaSystmes collodaux Mthodes de dtermination du potentiel zta Partie 1: Phnomnes lectroacoustiques et lectrocintiquesINTERNATIONAL STANDARDISO13099-1First edition2012-06-15Reference numberISO 13099-1:2012(E)BS ISO 13099-1:2012ISO 13099-1:2012(E)ii ISO

6、 2012 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2012All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from eit

7、her ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 13099-1:2012ISO 13099-1:2012(E) ISO 2012 All rights re

8、served iiiContents PageForeword ivIntroduction v1 Scope 12 Terms and definitions . 12.1 Electric double layer . 12.2 Electrokinetic phenomena 22.3 Electroacoustic phenomena . 43 Symbols . 54 Theory: general comments . 65 Elementary theories, Smoluchowskis limit for electrokinetics . 75.1 General . 7

9、5.2 Electrophoresis 75.3 Electroosmosis 85.4 Streaming current or potential . 85.5 Sedimentation potential or current . 86 Elementary theories, Smoluchowskis limit for electroacoustics 86.1 General . 86.2 OBriens theory for dynamic electrophoretic mobility . 96.3 Smoluchowski limit theory for dynami

10、c electrophoretic mobility . 97 Advanced theories 108 Equilibrium dilution and other sample modifications .10Annex A (informative) Electric double layer models .12Annex B (informative) Surface conductivity18Annex C (informative) Debye length 20Annex D (informative) Advanced electrophoretic theories

11、.21Annex E (informative) Advanced electroacoustic theories .24Bibliography .26BS ISO 13099-1:2012ISO 13099-1:2012(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standar

12、ds is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take

13、 part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to

14、 prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility th

15、at some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.ISO 13099 was prepared by Technical Committee ISO/TC 24, Particle characterization including sieving, Subcommittee SC 4, Particle characteriza

16、tion.ISO 13099 consists of the following parts, under the general title Colloidal systems Methods for zeta-potential determination: Part 1: Electroacoustic and electrokinetic phenomena Part 2: Optical methodsThe following part is under preparation Part 3: Acoustic methodsiv ISO 2012 All rights reser

17、vedBS ISO 13099-1:2012ISO 13099-1:2012(E)IntroductionThe basic theories and understanding of the electrokinetic and electroacoustic phenomena in a liquid suspension, an emulsion, or a porous body are presented within this part of ISO 13099 as an introduction to the subsequent parts, which are devote

18、d to specific measurement techniques.Many processes, from cleaning water, after either human or industrial fouling, to the creation of stable pharmaceutical suspensions, benefit from an understanding of the charged surfaces of particles. Also, causing the particles of a targeted mineral to have an a

19、ffinity with respect to air bubbles, is a mechanism employed in the recovery of some minerals.It should be noted that there are a number of situations where electrokinetic and electroacoustic measurements, without further interpretation, provide extremely useful and unequivocal information for techn

20、ological purposes. The most important of these situations are:a) identification of the isoelectric point (or point of zero zeta-potential) by electrokinetic titrations with a potential determining ion (e.g. pH titration);b) identification of the isoelectric point by titrations with other reagents su

21、ch as surfactants or polyelectrolytes;c) identification of a saturation plateau in the adsorption indicating optimum dosage for a dispersing agent;d) relative comparison of various systems with regard to their electric surface properties.The determination of zeta-potential, which is not a directly m

22、easurable quantity, but one that is established by the use of an appropriate theory, can be interpreted to establish the region of stability for some suspensions. By determining the isoelectric point, conditions for the optimum coagulation of particles prior to either capture in a filter bed or sett

23、ling out in a lagoon can be set to facilitate the clean-up of fouled water.This document follows the IUPAC Technical Report on measurement and interpretation of electrokinetic phenomena (Reference 1) and general References 25. ISO 2012 All rights reserved vBS ISO 13099-1:2012BS ISO 13099-1:2012Collo

24、idal systems Methods for zeta-potential determination Part 1: Electroacoustic and electrokinetic phenomena1 ScopeThis part of ISO 13099 describes methods of zeta-potential determination, both electric and acoustic, in heterogeneous systems, such as dispersions, emulsions, porous bodies with liquid d

25、ispersion medium. There is no restriction on the value of zeta-potential or the mass fraction of the dispersed phase; both diluted and concentrated systems are included. Particle size and pore size is assumed to be on the micrometre scale or smaller, without restriction on particle shape or pore geo

26、metry. The characterization of zeta-potential on flat surfaces is discussed separately.The liquid of the dispersion medium can be either aqueous or non-aqueous with any liquid conductivity, electric permittivity or chemical composition. The material of particles can be electrically conducting or non

27、-conducting. Double layers can be either isolated or overlapped with any thickness or other properties.This part of ISO 13099 is restricted to linear effects on electric field strength phenomena. Surface charge is assumed to be homogeneously spread along the interfaces. Effects associated with the s

28、oft surface layers containing space distributed surface charge are beyond the scope.2 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.2.1 Electric double layerNOTE The electric double layer (EDL) is a spatial distribution of electric charges that app

29、ears on and at the vicinity of the surface of an object when it is placed in contact with a liquid.2.1.1DebyeHckel approximationmodel assuming small electric potentials in the electric double layer2.1.2Debye length1characteristic length of the electric double layer in an electrolyte solutionNOTE The

30、 Debye length is expressed in nanometres.2.1.3diffusion coefficientDmean squared displacement of a particle per unit time2.1.4Dukhin numberDudimensionless number which characterizes contribution of the surface conductivity in electrokinetic and electroacoustic phenomena, as well as in conductivity a

31、nd dielectric permittivity of heterogeneous systemsINTERNATIONAL STANDARD ISO 13099-1:2012(E) ISO 2012 All rights reserved 1BS ISO 13099-1:2012ISO 13099-1:2012(E)2.1.5dynamic viscosityratio between the applied shear stress and the rate of shear of a liquidNOTE 1 For the purposes of this part of ISO

32、13099, dynamic viscosity is used as a measure of the resistance of a fluid which is being deformed by shear stress.NOTE 2 Dynamic viscosity determines the dynamics of an incompressible newtonian fluid.NOTE 3 Dynamic viscosity is expressed in pascal seconds.2.1.6electric surface charge densitycharges

33、 on an interface per area due to specific adsorption of ions from the liquid bulk, or due to dissociation of the surface groupsNOTE Electric surface charge density is expressed in coulombs per square metre.2.1.7electric surface potentialsdifference in electric potential between the surface and the b

34、ulk liquidNOTE Electric surface potential is expressed in volts.2.1.8electrokinetic potentialzeta-potential-potentialdifference in electric potential between that at the slipping plane and that of the bulk liquidNOTE Electrokinetic potential is expressed in volts.2.1.9GouyChapmanStern modelmodel des

35、cribing the electric double layer2.1.10isoelectric pointcondition of liquid medium, usually the value of pH, that corresponds to zero zeta-potential of dispersed particles2.1.11slipping planeshear planeabstract plane in the vicinity of the liquid/solid interface where liquid starts to slide relative

36、 to the surface under influence of a shear stress2.1.12Stern potentialdelectric potential on the external boundary of the layer of specifically adsorbed ionsNOTE Stern potential is expressed in volts.2.2 Electrokinetic phenomenaNOTE Electrokinetic phenomena are associated with tangential liquid moti

37、on adjacent to a charged surface.2 ISO 2012 All rights reservedBS ISO 13099-1:2012ISO 13099-1:2012(E)2.2.1electroosmosismotion of liquid through or past a charged surface, e.g. an immobilized set of particles, a porous plug, a capillary or a membrane, in response to an applied electric field, which

38、is the result of the force exerted by the applied field on the countercharge ions in the liquid2.2.2electroosmotic counter-pressureDpeopressure difference that is applied across the system to stop the electroosmotic flowNOTE 1 The electroosmotic counter-pressure value is positive if the high pressur

39、e is on the higher electric potential sideNOTE 2 Electroosmotic counter-pressure is expressed in pascals.2.2.3electroosmotic velocityveouniform velocity of the liquid far from the charged interfaceNOTE Electroosmotic velocity is expressed in metres per second.2.2.4electrophoresismovement of charged

40、colloidal particles or polyelectrolytes, immersed in a liquid, under the influence of an external electric field2.2.5electrophoretic mobilityelectrophoretic velocity per electric field strengthNOTE 1 Electrophoretic mobility is positive if the particles move toward lower potential (negative electrod

41、e) and negative in the opposite case.NOTE 2 Electrophoretic mobility is expressed in metres squared per volt second.2.2.6electrophoretic velocityeparticle velocity during electrophoresisNOTE Electrophoretic velocity is expressed in metres per second.2.2.7sedimentation potentialUsedpotential differen

42、ce sensed by two electrodes placed some vertical distance apart in a suspension in which particles are sedimenting under the effect of gravityNOTE 1 When the sedimentation is produced by a centrifugal field, the phenomenon is called centrifugation potential.NOTE 2 Sedimentation potential is expresse

43、d in volts.2.2.8streaming currentIstrcurrent through a porous body resulting from the motion of fluid under an applied pressure gradientNOTE Streaming current is expressed in amperes. ISO 2012 All rights reserved 3BS ISO 13099-1:2012ISO 13099-1:2012(E)2.2.9streaming current densityJstrstreaming curr

44、ent per areaNOTE Streaming current density is expressed in coulombs per square metre.2.2.10streaming potentialUstrpotential difference at zero electric current, caused by the flow of liquid under a pressure gradient through a capillary, plug, diaphragm or membraneNOTE 1 Streaming potentials are crea

45、ted by charge accumulation caused by the flow of countercharges inside capillaries or pores.NOTE 2 Streaming potential is expressed in volts.2.2.11surface conductivityKexcess electrical conduction tangential to a charged surfaceNOTE Surface conductivity is expressed in siemens.2.3 Electroacoustic ph

46、enomenaNOTE Electroacoustic phenomena arise from the coupling between the ultrasound field and electric field in a liquid that contains ions. Either of these fields can be primary driving force. Liquid might be a simple newtonian liquid or complex heterogeneous dispersion, emulsion or even a porous

47、body. There are several different electroacoustic effects, depending on the nature of the liquid and type of the driving force.2.3.1colloid vibration currentCVIICVIa.c. current generated between two electrodes, placed in a dispersion, if the latter is subjected to an ultrasonic fieldNOTE Colloid vib

48、ration current is expressed in amperes.2.3.2colloid vibration potentialCVUa.c. potential difference generated between two electrodes, placed in a dispersion, if the latter is subjected to an ultrasonic fieldNOTE Colloid vibration potential is expressed in volts.2.3.3electrokinetic sonic amplitudeESA

49、AESAamplitude is created by an a.c. electric field in a dispersion with electric field strength, E; it is the counterpart of the colloid vibration potential methodNOTE 1 See Reference 6.NOTE 2 Electrokinetic sonic amplitude is expressed in pascals.4 ISO 2012 All rights reservedBS ISO 13099-1:2012ISO 13099-1:2012(E)2.3.4ion vibration currentIVIa.c. electric current created from different displacement amplitudes in an ultrasound wave due to the difference in the effective mass or friction coefficient betwee