Colloidal suspension rheology

415 Pages·2011·7.259 MB·English

by  J Mewis, Norman Joseph Wagner

COLLOIDAL SUSPENSION RHEOLOGY
Colloidalsuspensionsareencounteredinamultitudeofnatural,biological,andindus-
trially relevant products and processes. Understanding what affects the flow behavior,
or rheology, of colloid suspensions, and how this flow behavior can be manipulated,
isimportantforsuccessfulformulationofproductssuchaspaint,polymers,foods,and
pharmaceuticals.Thisbookisthefirstdevotedtothestudyofcolloidalrheologyinallits
aspects.Withmaterialpresentedinanintroductorymanner,andcomplexmathematical
derivationskepttoaminimum,thereaderwillgainastronggraspofthebasicprinciples
of colloid science and rheology. Beginning with purely hydrodynamic effects, the con-
tributionsofBrownianmotionandinterparticleforcesarecovered,beforethereaderis
guidedthroughspecificproblemareassuchasthixotropyandshearthickening;special
classesofcolloidsuspensionsarealsotreated.Thetechniquesnecessaryformeasuring
colloidalsuspensionrheologyarepresentedalongwithmethodstocorrelateandinter-
prettheresults.Anessentialguideforacademicandindustrialresearchers,thisbookis
alsoidealforgraduatecourseuse.
jan mewis is Emeritus Professor of the Chemical Engineering Department at the
Katholieke Universiteit Leuven. He is involved in industrial and academic research in
complex fluids such as suspensions and polymer blends. Professor Mewis has lectured
allovertheworldandhaswrittenover200publicationsoncolloidscienceandrheology.
HewasChairmanoftheInternationalCommitteeonRheologyandisarecipientofthe
GoldMedaloftheBritishSocietyofRheologyandtheBinghamMedalofTheSociety
ofRheology(USA).
norman j. wagner receivedhisDoctoratefromPrincetonUniversityandisanamed
Professor and Chair of the Department of Chemical Engineering at the University of
Delaware.Hehasextensiveinternationalteachingandresearchexperience,andleadsan
activeresearchgroupcoveringfieldssuchasrheology,complexfluids,polymers,nano-
technology,andparticletechnology.ProfessorWagnerhasreceivedseveralawardsfor
hisresearchdevelopments,hasco-authoredover150scientificpublicationsandpatents,
andisontheeditorialboardsoffiveinternationaljournals.Hecurrentlyservesonthe
executive boards of the Society of Rheology and the Neutron Scattering Society of
America.
CAMBRIDGE SERIES IN CHEMICAL ENGINEERING
SeriesEditor
ArvindVarma,PurdueUniversity
EditorialBoard
ChristopherBowman,UniversityofColorado
EdwardCussler,UniversityofMinnesota
ChaitanKhosla,StanfordUniversity
AthanassiosZ.Panagiotopoulos,PrincetonUniversity
GregoryStephanopolous,MassachusettsInstituteofTechnology
JackieYing,InstituteofBioengineeringandNanotechnology,Singapore
BooksinSeries
Chau,ProcessControl:AFirstCoursewithMATLAB
Cussler,Diffusion:MassTransferinFluidSystems,ThirdEdition
CusslerandMoggridge,ChemicalProductDesign,SecondEdition
Denn,ChemicalEngineering:AnIntroduction
Denn, Polymer Melt Processing: Foundations in Fluid Mechanics and
HeatExchangers
DuncanandReimer,ChemicalEngineeringDesignandAnalysis:AnIntroduction
FanandZhu,PrinciplesofGas-SolidFlows
Fox,ComputationalModelsforTurbulentReactingFlows
Leal,AdvancedTransportPhenomena:FluidMechanicsandConvectiveTransport
MewisandWagner,ColloidialSuspensionRheology
Morbidelli,Gavriilidis,andVarma,CatalystDesign:OptimalDistributionofCatalyst
inPellets,Reactors,andMembranes
Noble and Terry, Principles of Chemical Separations with Environmental
Applications
Orbey and Sandler, Modeling Vapor–Liquid Equilibria: Cubic Equations of State
andtheirMixingRules
Petyluk, Distillation Theory and its Applications to Optimal Design of Separation
Units
RaoandNott,AnIntroductiontoGranularFlow
Russell, Robinson, and Wagner, Mass and Heat Transfer: Analysis of Mass
ContactorsandHeatExchangers
Slattery,AdvancedTransportPhenomena
Varma,Morbidelli,andWu,ParametricSensitivityinChemicalSystems
Colloidal Suspension
Rheology
JAN MEWIS
KatholiekeUniversiteitLeuven
NORMAN J. WAGNER
UniversityofDelaware
cambridge university press
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(cid:2)c J.MewisandN.Wagner2012
Thispublicationisincopyright.Subjecttostatutoryexception
andtotheprovisionsofrelevantcollectivelicensingagreements,
noreproductionofanypartmaytakeplacewithoutthewritten
permissionofCambridgeUniversityPress.
Firstpublished2012
PrintedintheUnitedKingdomattheUniversityPress,Cambridge
AcataloguerecordforthispublicationisavailablefromtheBritishLibrary
LibraryofCongressCataloguinginPublicationdata
Mewis,J.
Colloidalsuspensionrheology/JanMewis,NormanJ.Wagner.
p. cm.–(Cambridgeseriesinchemicalengineering)
Includesbibliographicalreferencesandindex.
ISBN978-0-521-51599-3
1.Rheology. 2.Suspensions(Chemistry) 3.Colloids. I.Wagner,NormanJoseph,1962– II.Title.
TP156.R45M49 2012
531′.1134–dc23 2011029383
ISBN978-0-521-51599-3Hardback
CambridgeUniversityPresshasnoresponsibilityforthepersistenceor
accuracyofURLsforexternalorthird-partyinternetwebsitesreferredto
inthispublicationanddoesnotguaranteethatanycontentonsuch
websitesis,orwillremain,accurateorappropriate.
ToRiaandSabine
Thislandmarkbookthoroughlydetailsthebasicprinciplesofcolloidscienceand
uniquelycoversallaspectsoftherheologyofcolloidalsuspensions,including
difficultandoftencontroversialtopicssuchasyieldstress,thixotropy,shapeeffects
andshearthickening,aswellaslatestdevelopmentsinmicrorheologyand
interfacialrheology.Theelegantpresentationstyle,focusingonthefundamental
concepts,bridgingengineeringandphysics,experimentandtheory,andpaying
attentiontotheinterplaybetweenmicrostructureandrheology,reflectsthevast
teachingandresearchexperienceoftheauthors,andmakesthebookamuch
neededreferenceforpractitioners,researchersandgraduatestudents.
DimitrisVlassopoulos
IESL-FORTH,Greece
Appropriately,thefirstbooktospanthesubjectofsuspensionrheologyisauthored
byJanMewis,apioneerinthefield,andNormWagner,whoseresearchhas
advancedmanyofthemodernfrontiers.Theirtextemergesfromalong-standing
collaborationinshortcoursesthathaveintroducedgraduatestudents,young
faculty,andindustrialresearcherstothefundamentalsandthepracticalitiesof
rheologicalphenomenaandtheirunderlyingprinciples.Afterabriefintroduction
tocolloidscienceandrheologythebookteachestheconsequencesoftherelevant
forces,i.e.,hydrodynamic,Brownian,electrostatic,polymeric,andvanderWaals,
throughdatafrommodelsystemsandresultsfromfundamentaltheory.Then
time-dependentphenomena,shearthickening,andtheeffectsofviscoelasticmedia,
inwhichthetwohavepavedtheway,receivespecialattention.Thetreatment
closeswithbriefaccountsofmicrorheology,electro-andmagnetorheology,and
two-dimensionalsuspensions.Thereismuchtolearnfromthistome!
WilliamBRussel
PrincetonUniversity
EversinceIlearnedthatMewisandWagnerwerepreparingColloidalSuspension
RheologyIhavebeeneagerlyawaitingitsarrival.Iwasnotdisappointed!Thebook
isverylogicallylaidout.Thereaderistoldwhatiscomingandkeyideasare
summarizedattheendofeverysection.Iespeciallylikethe“landmark
observations”thatfocuseachchapter.Everychapterhasatableofnotationandis
extensivelyreferencedincludingtitlesofarticles.Theconcisereviewofcolloidal
phenomenainchapter1isoutstandingandtheAdvancedTopicsinthefinal
chapter(microrheology,electroandmagneto-rheologyand2dimensional
rheology)areaspecialtreat.
ColloidSuspensionRheologyisthefirsttextinthisfieldandwillbemuch
appreciated.Suspensionsaregrowingrapidlyinacademicimportanceandarethe
keytosomanynewindustrialproducts.Rheologyisarapidandsensitivetoolto
characterizeboththeirmicrostructureandperformance.Thistextwillbeofgreat
excellentsupplementtocoursesincolloidsandrheology.
ChrisMacosko
UniversityofMinnesota&IPRIME
Contents
Preface pagexiii
Generallistofsymbols xvi
Usefulphysicalconstantsandvalues xx
1 Introductiontocolloidscienceandrheology . . . . . . . . . . . . . . . . . . . 1
1.1 Colloidalphenomena 1
1.1.1 Forcesactingonindividualcolloids 2
1.1.2 Colloidalinteractions 6
1.1.3 Phasebehaviorandcolloidalstability 15
1.2 Principlesofrheology 18
1.2.1 Basicconcepts 18
1.2.2 GeneralizedNewtonianfluids 24
1.2.3 Viscoelasticity 25
1.2.4 Applicationtocolloidaldispersions 30
Alookahead 32
Appendix:Secondvirialcoefficients 32
Chapternotation 33
References 34
2 Hydrodynamiceffects:Non-colloidalparticles . . . . . . . . . . . . . . . . . 36
2.1 Introduction 36
2.2 Landmarkobservations 37
2.2.1 Summary 40
2.3 Dilutesystems 41
2.3.1 Flowaroundandmotionofsingleparticles 41
2.3.2 Viscosityofdilutesuspensions 43
2.3.3 Summary 46
2.4 Semi-dilutesuspensions 46
2.4.1 Summary 51
2.5 Concentratedsuspensions 51
2.5.1 Microstructure 52
2.5.2 Viscosity 54
2.5.3 Otherstresscomponents 60
vii
viii Contents
2.5.4 Summary 62
2.6 Otherflowphenomena 63
2.6.1 Diffusionormigration 63
2.6.2 Inertialeffects 67
2.6.3 Sedimentation 68
2.6.4 Summary 69
AppendixA:DerivationofEinsteinexpressionforintrinsic
viscosity 70
AppendixB:Derivationofphenomenologicalequationsfor
suspensionviscosity 71
Chapternotation 72
References 73
3 Brownianhardspheres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
3.1 Introduction 80
3.2 Landmarkobservations 81
3.3 Structureandthermodynamicpropertiesofthehard
spherefluid 85
3.3.1 Pressureinahardspherefluid 86
3.3.2 Brownianforcesinconcentrateddispersions 87
3.4 Rheologyofdiluteandsemi-dilutedispersions 90
3.5 Concentrateddispersions 95
3.5.1 Zeroshearviscosity 95
3.5.2 Linearviscoelasticity 101
3.5.3 Steadyshearrheology 105
3.5.4 Hardspherecolloidalglasstransitionand
mode-couplingtheory 109
Summary 112
AppendixA:PrinciplesoftheSmoluchowskiequationfor
dispersionmicromechanics 113
AppendixB:Theroleofhydrodynamicinteractions 114
AppendixC:Osmoticpressureforahardspheresolid 115
Chapternotation 116
References 116
4 Stablesystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
4.1 Introduction 122
4.2 Landmarkobservations 123
4.3 Electrostaticallystabilizedsystems 127
4.3.1 Diluteandsemi-dilutesuspensions 127
4.3.2 Concentratedsuspensions 131
4.4 Stericallystabilizedsystems 137
4.4.1 Mechanism 137
4.4.2 Dilutesystems 138
4.4.3 Non-dilutesystems 139
4.5 Electrostericallystabilizedsystems 147
Contents ix
Summary 149
Chapternotation 149
References 150
5 Non-sphericalparticles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
5.1 Introduction 155
5.2 Landmarkobservations 155
5.3 Particlemotion 160
5.4 Rheologyofdilutesuspensionsofnon-sphericalparticles 163
5.5 Semi-dilutesuspensionsofnon-sphericalparticles 167
5.6 Concentratedsuspensionsofnon-sphericalparticles 168
5.7 Chargednon-sphericalparticles 172
Summary 173
Appendix:Structuraldescriptionofthestressesinfibersuspensions 173
Chapternotation 175
References 176
6 Colloidalattractionsandflocculateddispersions . . . . . . . . . . . . . . 180
6.1 Introduction 180
6.1.1 Methodstoinduceinterparticleattractionand
flocculation 181
6.2 Landmarkobservations 183
6.3 Phasebehavior,microstructure,andstatediagrams 187
6.3.1 Equilibriumphasebehavior 187
6.3.2 Flocsandfractals 188
6.3.3 Effectofflowonflocstructure 190
6.3.4 Stableclusters 193
6.3.5 Percolation,gelation,jamming,andvitrification 193
6.4 Rheologyatlowvolumefractions 201
6.5 Concentrateddispersions 203
6.6 Rheologyofgelledsystems 206
6.6.1 Moduliandyieldstressofgels 207
6.7 Kineticsofaggregatingsystems 214
6.8 Polymerbridgeflocculation 214
Summary 215
Appendix:Influenceofweakattractionsonnearhardsphere
dispersionrheology 216
Chapternotation 217
References 218
7 Thixotropy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
7.1 Introduction 228
7.2 Theconceptofthixotropy 228
7.2.1 Definition 228
7.2.2 Thixotropyversusviscoelasticity 230
7.3 Landmarkobservations 231
x Contents
7.4 Rheologicalphenomena 232
7.4.1 Start-upandintermittentflows 232
7.4.2 Hysteresisloops 234
7.4.3 Stepwisechangesinshear 235
7.4.4 Creeptests 236
7.4.5 Oscillatoryflow 237
7.5 Constitutiveequations 239
7.5.1 Structurekineticsmodels 239
7.5.2 Integralmodels 244
Summary 245
Appendix:Parameterestimationandmodelassessment 245
Chapternotation 248
References 248
8 Shearthickening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
8.1 Introduction 252
8.2 Landmarkobservations 253
8.3 Shearthickeningcolloidaldispersions 261
8.3.1 Dilutedispersions 261
8.3.2 Concentrateddispersions 265
8.3.3 Non-sphericalparticledispersions 274
8.3.4 Extensionalthickening,confinement,andfieldeffects 275
8.3.5 Elastohydrodynamiclimitofshearthickening 277
8.3.6 Modelsforpredictingtheonsetofshearthickening 278
8.4 Dilatancyandshearthickeninginsuspensions 281
Summary 283
Chapternotation 284
References 284
9 Rheometryofsuspensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
9.1 Introduction 291
9.2 Basicmeasurementgeometries 291
9.2.1 Coneandplate 292
9.2.2 Paralleldisks 292
9.2.3 Coaxialcylinders 293
9.2.4 Capillaryflow 294
9.3 Measurementproblemsandbasicprocedures 295
9.3.1 Measurementproblems 295
9.3.2 Selectionofmeasurementgeometry 297
9.3.3 Generalmeasurementprocedures 299
9.4 Specificmeasurementprocedures 300
9.4.1 Wallslip 300
9.4.2 Yieldstress(shear) 305
9.4.3 Compressiveyieldstress 313
9.4.4 Thixotropy 315
9.4.5 Largeamplitudeoscillatoryshearflow(LAOS) 316