Complex fluids and applications in the processindustries: fluid homogenization and transport

Tuomas Koiranen / LUT, Finland

Introduction to complex fluids problematics(Definitions, classification), rheologiesprocess conditions in applications and typicalprocess equipment

Complexfluidsdefinitions:1)Fluidsshowingnon-linearviscousbehaviour,aswellasviscoelasticmaterials,areComplexFluids.(Complexfluidsengineeringlaboratory,UniversidadHuelva,Spain)

2)Typicallymulticomponent systems,complexfluidsarehighlynonlinearwithrespecttocomposition changes,andoftenthefluidstatesthatprovidethedesiredmechanicalorchemicalpropertiesaremetastableandaccessibleonlythroughpreciselycontrolledprocessingandformulationsteps.(CarnegieMellon,CenterforComplexfluidsEngineering)

- SummaryofDefinitions:Complexfluidshave2ormorefluidphaseswhichhavephysicalinteractionwitheachother,andtheycanhavetypicallyacomplexmicrostructure.Fluidphasesrefertodispersesystems.

Classificationofdispersesystems

Liquid-gas: foams,gas-liquiddispersionsGas-liquid: fog,liquidaerosolsGas-solid:solidaerosols,powdersSolid-gas: solidfoamsLiquid-liquid: liquid-liquid dispersions ,emulsionsSolid-liquid: gels,pastesLiquid-solid: solid-liquid suspensions,slurries, sols

(BjörnLindman,SurfactantsandCellulosepolymersinaqueoussolutions-course,Physicalchemistry,LundUniversity,Sweden,2013)

Continuo

usm

edium

Dispersedphase GAS LIQUID SOLID

GAS None Liquidaerosol(fog,hairsprays)

Solidaerosol(airparticles,

smoke)LIQUID Foam

(whippedcream,shavingcream,flotationcell

foam)

Emulsion(milk,

mayonnaise,lotions,

ointments)

Sol(blood,

pigmentedink,fibersuspensions)

SOLID Solidfoam(aerogel,polymerfoam,pumice)

Gel(agar,gelatinjelly)

Solidsol(gemstone,jewel)

Bulkrheologies(EKATOMixinghandbook,2000)- Themacroscalefluidrheology

Bulkrheologies- Themacroscalefluidrheology

Sol-gelviscosityexampleasafunctionofshearrateatdifferenttemperatures.Gellingat20°Ccurve.

Bulkrheologies- Themacroscalefluidrheology

Solutionrheologyexample:Sol-geltransition

Illustrationoftheviscoelasticstructureandgelationphenomenonatelevatedtemperature. (Metzger2011,Kalanti2015)

Microrheology(Rep.Prog.Phys.68 (2005)685,J.Non-NewtonianFluidMech.112 (2003)237).

1) Microrheologyisconcernedwithhowmaterialsstoreanddissipatemechanicalenergyasafunctionoflengthscale.

2) Itiscloselyconnectedtothefieldofmicrofluidics(inkjetprinting,microreactors,valvesetc.)

3) Classification(Waigh2005)

1) Largeamplitudeoscillatoryshear(LAOS)behaviorstudiesofcomplexfluidsinformingmicrostructures.

TypeI.Strainthinning:mostpolymersolutionsormeltsTypeII.Strainthickening: iondipolesorhydrogenbonding(PVA+Na2B4O7,alcohol+claywithwaterbridge)TypeIII.Weakstrainovershoot:surfactantsolutions,biopolymers(dough),liquidemulsionsTypeIV.Strongstrainovershoot:HASEpolymers(acid/acrylatewithethoxylatedhydrophobe)

Microstructures(Quemada,1997)

Requiredshearratesindifferentapplications

Process Shearrate,1/s ApplicationParticlesedimentationinsuspension 1E-6-1E-3 paints,medicines

Extrusion,pipeflow 1-1E+3 food,polymersMixinginstirredtank 10-1000 food,chemicals

Spraydrying 1E+3-1E+5 food,chemicalsHighspeedcoating 1E+4-1E+6 paper

Typicalshearratesofdifferentprocesses(Fried,1995;Pauletal.2004;Kessler,1998)

MixingpowerforProductionofO/Wdispersions(Paulet.al,2004)

Emulsions(JohnTexter,PracticalSurveycourseonsmallparticleformation,StriderRes.Co.2009)- Emulsionsareunstablebutmicroemulsionsarestable.- Criticalmicelleformingconcentration

+chargedSmalltolongchain

- chargedlongtosmallchain

Mesophases(JohnTexter,PracticalSurveycourseonsmallparticleformation,StriderRes.Co.2009)

Microstructureformation(Lindman,2013)

PARTICLESTABILIZATION- Hardwallandelectrostaticrepulsion,andVanderWaalsattractionforcesdefinetheelectrostaticstabilizedcolloids

-Instericstabilizationpolymerchainsformsterichindranceforparticlestoformaggregates

MixersforcomplexfluidsStaticmixers- Largevarietyoffluidsmixing

(Laminar/Turbulent,S/L/G)

- Shortresidencetimes(τc)

- Largeshearrateregionanddispersedphase/continuousphase–ratios(Rµ)basedondifferentgeometries

- Simplesizingprocedures(pump)P = ∆𝑝𝑄

MixersforcomplexfluidsMixingtanks- Largeresidencetimeregions- Largedistributionsofshearrates- Liquids,emulsions,gels,pastes

Somespecialcases- Ultrasonicationcanbeused

foremulsification,difficultslurryformations(e.g.nanomaterialwetting).

- Electrocapillarity:Internalphasebreaksintoemulsiondropletincontinuousphasewhenelectricpotentialdifferenceisappliedbetweenphases(Watanabeetal.,1978)

- Initialdispersionispressedthroughporousmembranetoformemulsion(Omietal.,1994).

Summaryofhomogenizationmethods

- Complexfluidscanalsobepresent inchangingprocessconditions:Chemicalreactions,crystallizations,meltingprocessesetc.

Typeofcomplexfluids MixersusedPaints rotor-stators,stirredtanks(shearingaction)Adhesives kneaders,rotor-statorsPaintpastes rollmills,ballmills,tubemills,rotor-stators

Greasesstirredtanks(dualaction),kneaders(sigmablade,dispersionblade)

Ceramics(heavyconsistency)

panmixers,pugmills,planetarymills

Fibrousmixeskneaders,sigma/dispersionblade),intensivemixers(Banburytype)

Resins(heavyconsistency)

kneaders,rollmills,intensivemixers(Banbury,rotor-stator)

Rubbers&Elastomers(stiffgels)

intensivemixers,rollmills,kneaders

Mineralslurriesstirredtanks(dualaction),in-linemixers(rotor-stators)

Emulsions(food,cosmetics,pharma)

paddlestirredtanks,staticmixers,in-linemixers(rotor-stators),pressurehomogenizer

Foams(gas-liquid) Gas-liguidInjectors,stirredtanks

Complexfluidstransport- Centrifugalpumpsarethemostcommonpumpsforfluidtransport- Theproblemsarisetypicallyfor- 1)shearthickeningfluids=>viscosityincreases=>flowratedecreases- 2)highsolidcontents=>materialabrasion- 3)preservingfluidmicrostructure=>shearratechangesoccur- Specialpumpscanbeusedincomplexfluidstransport:peristaltic

pumps,positivedisplacementpumpslikeeccentricscrewpumps(e.g.FlowroxLtd)

Literature:Equipment

EKATOHandbookofMixingTechnology,EKATORühr- undMischtechnikGmbH, 2000

Matijevic,E.,Good, R.J.(eds.),Surfaceandcolloid scienceVol13,Ch.1:Electrochemistry ofoil-water interfaces, Springer, USA,1984

McDonough,R.J., MixingfortheProcess Industries, VanNostrand Rheinhold, NewYork,USA,1992

Paul,L.E.,Atiemo-Obeng,V.,Kresta, S.,(eds.),Handbookofindustrial mixing,Wiley,2004

Pehrman, N.,Slurryflowsinprogressivecavityandperistaltic hosepumps, LUT2014

Thakur,R.K.etal.,Staticmixers intheprocess industries - areview,TransIChemE81A,(2003)787-826

Grace,H.P.,ChemEngCommun14(1982),225–277

Zlokarnik,M.,Judat,H.,Ullmann's EncyclopediaofIndustrial Chemistry, Vol.B2.,Ch.25:Stirring ,VCHVerlagsgesellschaftGmbH, Germany,1988

Literature:Processes

Florence, A.T.,Attwood,D.(eds.),Physicochemical principles ofpharmacy,Pharmaceuitical press,UK, 2011

Dickinson, E.,Leser, M.(eds.),Foodcolloids – self-assemblyandmaterialscience, RSCpublishing, UK, 2007

Fried,J.R.,Polymerscienceandtechnology, Prentice Hall,USA,1995

Kessler, H.G.,Foodandbioprocessengineering – dairytechnology, VerlagA.Kessler,Germany,1998

Mixinginpolymerprocessing, Rauwendaal,C.(ed.),MarcelDekker,USA,1991

Omi,S.,Katami,K.,Yamamoto,A.,Iso,M.,Synthesisofpolymeric microspheres employingSPGemulsification technique, J.Appl. Polym.Sci.51(1994)1-11

Watanabe,A.etal.,J.Colloid InterfaceSci64(1978)278

Literature:Complex fluids, dispersesystems,rheologyandmicrorheology

Chen, D.T.etal.,Rheological microscopy:localmechanicalproperties frommicrorheology, Phys.Rev.Lett.90(2003)108301-1- 108301-4

Lindman, B.,Surfactantsandcellulose polymersinaqueoussolutions (course material),PhysicalChemistryDept.,Lund University,Sweden,2013.

Luckham,P.F.,Rossi,S.,Thecolloidal andrheological properties ofbentonite suspensions, AdvancesinColloid andInterfaceScience82(1999)43-92

Texter, J.,Practical surveycourseonsmallparticle formation (coursematerial), StriderResearch Company,USA,2009

Quemada,D.,Rheological modelling ofcomplex fluids.I.Theconceptofefectivevolumefraction revisited,Eur.Phys.J.AP1(1998)119-127

Quemada,D.,Berli, C,Energyofinteraction incolloids anditsimplications inrheological modeling,AdvancesinColloid andInterfaceScience98(2002)51-85

Gelbart, W.M.,Ben-Shaul,A.,The“New”Scienceof“Complex Fluids”, J.Phys.Chem.100(1996)13169-13189

Waigh,T.A.,Microrheologyofcomplex fluids, Rep.Prog.Phys.68(2005)685–742

Sim,H.G.,Ahn,K.H.,Lee,S.J.,J.Non-Newtonian FluidMech.112(2003)237–250

MezgerT.TheRheologyHandbook.3rdEdition, VincentzNetwork, 2011.

KalantiA.2014.Basicsofrheology(course materialinFinnish), AntonPaar.Imatra,Finland,2015.

Someresearchquestions

1)Istheresponseofoneprobeparticleatruemeasureofthebulkrheology?Aninterconnectionofmicrostructurestobulkrheologyiswelcome.

2)Theequipment selectionandsizingarebasedondynamicviscositydata.Elasticandviscousmodulidataareavailableforavastamountofdifferentcomplexfluidsystems.Focusalsofordynamicrheologymeasurements.

3)Complexfluidstructuresformation.Systematic,uniformandtechno-scientificapproachforproductdesign?e.g. formationenergies,characteristicresidencetimes,criticalsurfaceareas,etc.

THANKYOU/KIITOS