Nanoporous anodic alumina membranes: transport properties and replication

2005·6.7 MB·English

by  Odom, Damian J.

NANOPOROUSANODICALUMINAMEMBRANES:TRANSPORTPROPERTIES
ANDREPLICATION
By
DAMIAN ODOM
J.
ADISSERTATIONPRESENTEDTOTHEGRADUATESCHOOL
OFTHEUNIVERSITYOFFLORIDAINPARTIALFULFILLMENT
OFTHEREQUIREMENTSFORTHEDEGREEOF
DOCTOROFPHILOSOPHY
UNIVERSITYOFFLORIDA
2005
Copyright2005
by
DamianJ.Odom
Tomyfamily,fortheircontinuedloveandsupport.
ACKNOWLEDGMENTS
Manyindividualshaveinfluencedandadvisedmeprofessionallyandpersonally
overtheyears. Theirhelp,guidanceandsupporthaveenabledmetowritethisPh.D.
dissertation. First,IwouldliketothankDr.EdwardHealy,myanalyticalandinorganic
chemistryprofessorattheUniversityofNorthFlorida. Heshowedmehowtolookahead
intomyprofessionalcareerandtomakeplans(whileremainingflexible)forgetting
there. He,aswellasmanyothers,inspiredandpushedmeontograduateschool.
Iwouldliketothankpreviousadvisor,ProfessorLaurieGower,whomIstudied
underandearnedmyMSdegreeinMaterial’sScience&Engineering. Thosefewyears
hadledtomanymemoriesandongoingfriendships. Surprisingly,todayinanalytical
chemistryIamusingmanyoftheconceptsandskillsIlearnedthen.
Iwouldliketothankmycurrentadvisor(ProfessorCharlesR.Martin)forhis
assistance,ampleadvice,endlesssupport,andtheopportunitytoworktowardmyPhD. I
havemetmanyfriendshere,andhavehadmanypositiveexperiencesinhisgroup,all
whilelearninghowtoworkmoreindependentlyandassertively.
Withtimeanygoodgroupbringscontactwithmanygoodpost-docs. Becauseof
theirimmenseinfluenceonmyearlydevelopmentinmygraduatecareer,Iwouldliketo
thankSangBokLee,MarcWirtz,andPunitKohliformanylate-nightdiscussionsabout
research,scienceandlifeingeneral. Theyshowedgreatprofessionalismandleadership
duringtheirtimeinthisgroup. ManygraduatestudentsIhavemet,havemadethe
learningprocessalotmorefun:DavidMitchell,ScottMiller,ShufangYu,NaichoaLi,
IV
ChadHarrell,ElizabethHeins,LiisaKauri,LacramiaoraTrofin,JohnWharton,Fatih,
andRobbieSides. IwouldalsoliketothankElizabethHeins,ShufangYu,RobbieSides
andCharleyMalpassforreviewingthismanuscript. Thisistonameafew,butsomany
peoplehavebeenpositiveinfluencesandfriendsovertheyears.
Fortheirsupportandundyingloveoverthemanyyears,Iwouldliketothankmy
parents,SolomanandBobbieOdom. Theyhaveshowedgreatpatienceandwisdomas
parentsandasmyfriends. WithouttheirteachingsandlessonsIwouldnothavebeen
preparedforthejourneyoflife. Iwouldalsoliketothankmyextendedfamilymembers.
TheyhaveallraisedmeandguidedmeastheirsonorbrotherasIhavegonethroughlife.
Finally,Iwouldliketothankmysoon-to-bewife,NicoleGordon. Shehas
enduredalot,asIhavetriedtocompletethisdegreeandspentmanyanguishedours
editingthisbodyofwork. Mostimportant,shehasshownmethereismoretolifethan
justalabandscience.
v
TABLEOFCONTENTS
Page
ACKNOWLEDGMENTS iV
LISTOFTABLES viii
LISTOFFIGURES ix
ABSTRACT xiii
CHAPTER
1 INTRODUCTIONANDBACKGROUND 1
Track-etchedandNanoporousAnodicAluminaMembranes 2
Track-EtchMembranes 2
NanoporousAnodicAluminaMembranes 5
SeparationsBasedonPorousMembranes 8
SilaneModification 12
LangmuirAdsorptionIsotherm 13
ScanningElectronMicroscopy 16
ElectrolessandElectrochemicalDeposition 21
ElectrolessDeposition 21
ElectrochemicalDeposition 24
DissertationOverview 25
2 TRANSPORTRATEANDSELECTIVITYINSILANEMODIFIED
NANOPOREALUMINAMEMBRANES 27
Introduction 27
Experimental 28
MembraneModification 29
TransportExperiments 29
Resultsanddiscussion 32
TransportofNi2+and2,4-DimethylphenolthroughUntreated
VersusOctadecyltrimethoxy-TreatedMembranes 32
TransportofaHomologousSeriesofHydrophobic
PermeateMolecules 35
RateandSelectivityofTransportwithourSupportedLiquid
vi
Membranes 52
Conclusions 57
3 TRANSPORTRATEANDSELECTIVITYWITHSELECT
SILANESFORTHESURFACEMODIFICATIONOFNANOPORE
ANODICALUMINAMEMBRANES 59
Introduction 59
Experimental 59
Resultsanddiscussion 61
TransportwithDiPSandDiPKSModifiedMembranes 61
TransportwithCF3SModifiedMembranes 68
Conclusions 74
4 TRANSPORTRATEANDSELECTIVITYINSILANE
MODIFIEDNANOPOREANODICALUMINAMEMBRANES
ANDPHDEPENDANCE 76
Introduction 76
Experimental 79
Resultsanddiscussion 80
PHDependantTransportUtilizingODSModifiedMembranes 80
SolutionpHBasedConcentrationandSeparation
of2-NitrophenolandPyridineBasedonSolutionpH 90
CompetitiveSeparationStudies 92
Conclusions 95
5 PRODUCTIONOFPOLYMERICREPLICAMEMBRANESOF
TRACK-ETCHANDNANOPOROUSANODICALUMINA
MEMBRANES 97
Introduction 97
Experimental 99
Resultsanddiscussion 103
SelectionMoldMaterial 103
CompleteMoldMethodAppliedtoTrack-EtchedMembranes Ill
CompleteMoldMethodAppliedtoNanoporousAnodic
AluminaMembranes 115
TheIncompleteMoldMethod 118
Conclusions 123
6 CONCLUSIONS 125
7 LISTOFREFERENCES 130
8 BIOGRAPHICALSKETCH 140
vii
1-
2- LISTOFTABLES
Table page
1 Selectedsolutionsforelectrolessdeposition 23
1 CalculatedselectivitiesforODS-treatedBP20andCP200membranes 39
22--2. ContactanglemeasurementsofphenolsolutionsonanODS-treated
BP20membrane 44
3-
2-3. Calculatedpartitioncoefficientsandselectivitiesbasedonbulksolution
extractions 48
2-4. CalculatedselectivitiesforODS-treatedBP20membranes,withkerosene
andmineraloilssubphases 54
5. CalculatedtransportratesforphenolandTMPintoandoutofbulkphasesof
keroseneandmineraloil 56
1. FwliutxheosutfotrheDpirPeSseanncdeDoifPaKSs-utbrpehaatseed(B2Pm2M0mfeeemdbcroannceenstwraittihonasn)d 59
3-2. FluxesforanCF3S-treatedBP20membraneand2mMfeed
concentrations 69
3-3. Contactanglemeasurementsofp-cresolandanilineonODSand
CF3S-treated20BPmembranes 71
viii
LISTOFFIGURES
Figure page
1-1 Thecommercialtrack-etchingprocess 3
1-2 Scanningelectronmicrographsofcommercialpolycarbonate
track-etchmembranes 4
11--3 Electrochemicalproductionofananoporousanodicaluminamembrane 6
21--4 SEMmicrographsofcommercialandin-housenanoporousanodic
aluminamembranes 8
1-5 Principlemembranetransportmechanisms 11
1-6 Stepsofsurfacesilanizationprocess 13
1-7 Diagramofascanningelectronmicroscope(SEM) 19
8 Electronbeam-to-sampleinteractions 19
1 U-tubepermeationcellset-up 30
2-2...Membraneassemblywithoutasubphase 31
2-3 TransportofNi2+A),and2,4-dimethylphenol(DMP)B)withCP200
membrane(0)andoctadecyltrimethoxysilane(ODS)treatedCP200
membrane() 34
2-4 Vaporandsilanelayerdiffusionsmechanisms 35
2-5 Homologousseriesofpermeatemoleculesandtheirrespectivestructures 37
2-6 FluxplotsforODS-treatedA)BP20andb)CP200membranes
witha2mMfeedsolution 38
2-7 Fluxofphenolvs.phenolfeedconcentrationforanODS-treated
BP20membrane 42
IX
2-8A BulksolventpartitiondataforA)phenolandB)p-cresol
usedtodeterminepartitioncoefficients 46
2-8B BulksolventpartitiondataforA)DMPandB)TMP
usedtodeterminepartitioncoefficients 47
2-9 Fluxofphenolvs.phenolfeedconcentrationforanODS-treated
BP20membranecontainingkerosene 49
2-
2-10 Fluxofphenolvs.phenolfeedconcentrationforanODS-treated
3- BP20membranecontainingmineraloil 50
2-11 PBl)otmsinfeorraBlPo2il0sOuDbSp-htarseeatweitdhmaem2bmraMneasnawliyttehafeAe)dksoelruotsieonne,and 53
12 U-tubepermeationcellset-upwithorganicsolvent 55
1 Silanesusedforanodicaluminamembranemodification 61
3-2 TransportwithDiPSandDiPKS-treatedmembranes 63
3-
3-3 TransportwithDiPSandDiPKS-treatedmembraneswithakerosene
4- Subphase 64
3-4 TransportwithDiPSandDiPKS-treatedBP20membraneswitha
mineraloilsubphase 65
3-5 TransportwithaCFjS-treatedBP20membranewithincreasing
concentrationsofanalyte 68
3-6 FluxversusincreasingfeedconcentrationsofphenolwithaCF3S-treated
BP20membrane 70
7 Fluxofp-cresolandanilinewithODSandCFaS-treatedmembranes 73
1 StructuresandpKavaluesforA)aniline,B)2-nitrophenol,
C)benzoicacidandD)pyridine 77
4-2 CalculatedA)alphavalues,andB)theexpectedfluxtrendforaniline
basedonapKaof4.6 79
4-3 CalculatedalphaandmeasuredfluxversusfeedpFIfor
A)2-nitrohpenolandB)pyridine 82
4-4 CalculatedalphaandmeasuredfluxversusfeedpHfor
A)benzoicacidandB)aniline 83
x