Polymer brushes [Elektronische Ressource] : wetting properties and m_63-patterning [my-patterning] / vorgelegt von Sebastian Georg Johannes Emmerling

Dr. Sebastian Emmerling

Informations

• Publié par: johannes_gutenberg-universitat_mainz
• Publié le: 01 janvier 2010
• Nombre de lectures: 10
• Langue: English
• Poids de l'ouvrage: 5 Mo

Extrait

PolymerBrushes
—
WettingPropertiesandm-Patterning
Dissertation
zurErlangungdesGrades
,,DoktorderNaturwissenschaften”
imPromotionsfach Chemie
amFachbereichChemie,PharmazieundGeowissenschaft
derJohannesGutenberg-Universita¨tMainz
vorgelegtvon
SebastianGeorgJohannesEmmerling
geboreninKandel,Pfalz
Mainz,2010Dekan: Prof. Dr. PeterLangguth
1. Berichterstatter: Prof. Dr. JochenS.Gutmann
2. Berichterstatter: Prof. Dr. RudolfZentel
Tagdermu¨ndlichenPru¨fung: 23.09.2010DievorliegendeArbeitwurdeamMax-Planck-Institut fu¨r
Polymerforschung inMainzunterAnleitungvon
Prof. Dr. JochenS.Gutmann
inderZeitvonNovember2007bisAugust2010angefertigt.”Credoutintelligam.”
Saint Augustine(354-430AD),BishopofHippoAbstract
In this work polymer brushes on both flat and curved substrates were pre-
paredby graftingfromandgraftingtotechniques.
The brushes on flat substrates were patterned on the mm-scale with the use
of an inkjet printer. Thus it was demonstrated that chemistry with an inkjet
printer is feasible. The inkjet printer was used to deposit microdroplets of
acid. The saponification of surface-immobilized ATRP initiators containing
anesterbondoccurredinthesemicrodroplets. Thechangesinthemonolayer
of ester molecules due to saponification were amplified by SI-ATRP. It was
possibletocorrelatethepolymerbrushthicknesstoeffectivenessofsaponifi-
cation. The use of an inkjet printer allowed for simultaneously screening of
parameters such as type of acid, concentration of acid, and contact time be-
tweenacidandsurface. Adip-coaterwasutilizedinordertotestthesaponifi-
cationindependentofdropletevaporation. Theadvantageofthisdeveloped
processisitsversatility. Itcanbeappliedtoallsurface-immobilizedinitiators
containingesterbonds.
The technique has additionally been used to selectively defunctionalize the
initiatormoleculescoveringamicrocantileverononesideofacantilever. An
asymmetric coating of the cantilever with polymer brushes was thus gener-
ated. An asymmetric coating allows the useof amicrocantilever for sensing
applications.
Thepreparationofnanocompositescomprisedofpolyorganosiloxanemicro-
gel particles functionalized with poly(ethyl methacrylate) (PEMA) brushes
andlinear,butentangled,PEMAchainsisdescribedinthesecondmajorpart
of this thesis. Measurement of the inter-particle distance was performed us-
ingscanningprobemicroscopyandgrazingincidencesmallangleX-rayscat-
7tering. The matrix molecular weight at which the nanocomposite showed
microphase separation was related to abrupt changes in inter-particle dis-
tance. Microphase separation occurred once the matrix molecular exceeded
the molecular weight of the brushes. The trigger for the microphase sep-
aration was a contraction of the polymer brushes, as the measurements of
inter-particle distance have revealed. The brushes became impenetrable for
the matrix chains upon contraction and thus behaved as hard spheres. The
contractionledtoalossofanchoringbetweenparticlesandmatrix,asshown
bynanoweartestsusinganatomicforcemicroscope.
13Polyorganosiloxanemicrogelparticleswerefunctionalizedwith Cenriched
poly(ethyl methacrylate) brushes. New synthetic pathways were developed
13inordertoenrichnottheentirebrushwith C,butonlyexclusivelyselected
13regions. Cchemicalshiftanisotropy,anadvancedNMRtechnique,canthus
be used in order to gather information about the extended conformations in
13the C enriched regions of the PEMA chains immobilized on the m-gel-g-
PEMAparticles.
The third part of this thesis deals with the grafting to of polymeric fullerene
materialsonsiliconsubstrates. Activeesterchemistrywasemployedinorder
to prepare the polymeric fullerene materials and graft these materials cova-
lentlyonamino-functionalizedsiliconsubstrates.
iContents
Abstract 7
1 Introduction 1
2 Fundamentals 3
2.1 Thinfilmcoatings . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.1 AtomTransferRadicalPolymerization(ATRP) . . . . . 4
2.1.2 CoatingTechniques. . . . . . . . . . . . . . . . . . . . . 12
2.1.3 Surface-attachedpolymers . . . . . . . . . . . . . . . . 15
2.2 PolymerBrushes . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.2.1 ”Graftingfrom”-Surface-initiatedpolymerization . . 18
2.2.2 TheoryofPolymerBrushes-flatinterfaces . . . . . . . 28
2.2.3 TheoryofPolymerBrushes-curvedinterfaces . . . . . 38
2.3 Nanocomposites . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
3 ”Graftingfrom”-Polymerbrushesonflatsubstrates 47
3.1 Patterning of a surface immobilized ATRP initiator with an
inkjetprinter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
3.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 48
3.1.2 Syntheses . . . . . . . . . . . . . . . . . . . . . . . . . . 52
3.1.3 Applicationofacidswiththeinkjetprinter . . . . . . . 55
3.1.4 Application of acids for investigation of time depen-
denceofsaponificationreaction . . . . . . . . . . . . . 57
3.1.5 SI-ATRPofMMA . . . . . . . . . . . . . . . . . . . . . . 58
3.1.6 Dataacquisitionandtreatment . . . . . . . . . . . . . . 59
iii