surface chemistry on self-assembled monolayers ?· surface chemistry on self-assembled monolayers...
Post on 01-Aug-2018
Embed Size (px)
Surface chemistry on self-assembled monolayers
Document VersionPublishers PDF, also known as Version of Record (includes final page, issue and volume numbers)
Please check the document version of this publication:
A submitted manuscript is the author's version of the article upon submission and before peer-review. There can be important differencesbetween the submitted version and the official published version of record. People interested in the research are advised to contact theauthor for the final version of the publication, or visit the DOI to the publisher's website. The final author version and the galley proof are versions of the publication after peer review. The final published version features the final layout of the paper including the volume, issue and page numbers.
Link to publication
General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright ownersand it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.
Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal ?
Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.
Download date: 01. Aug. 2018
SSuurrffaaccee CChheemmiissttrryy oonn SSeellff--aasssseemmbblleedd MMoonnoollaayyeerrss
ter verkrijging van de graad van doctor aan de Technische Universiteit Eindhoven, op gezag van de rector magnificus, prof.dr.ir. C.J. van Duijn, voor een
commissie aangewezen door het College voor Promoties in het openbaar te verdedigen
op maandag 26 oktober 2009 om 16.00 uur
geboren te Jena, Duitsland
Dit proefschrift is goedgekeurd door de promotoren: prof.dr. U.S. Schubert en prof.dr. J.-F. Gohy Copromotor: dr. S. Hppener This research has been financially supported by the Dutch Organization for Scientific Research, NWO (VICI award for U.S. Schubert). Cover design: Daan Wouters and Claudia Hnsch Printed by: PrintPartners Ipskamp, Enschede, The Netherlands Surface Chemistry on Self-assembled Monolayers by Claudia Hnsch Eindhoven: Technische Universiteit Eindhoven 2009 A catalogue record is available from the Eindhoven University of Technology Library ISBN: 978-90-386-2026-8
SSuurrffaaccee CChheemmiissttrryy oonn SSeellff--aasssseemmbblleedd MMoonnoollaayyeerrss
Kerncommissie prof.dr. U.S. Schubert (Eindhoven University of Technology) prof.dr. J.-F. Gohy (Eindhoven University of Technology) dr. S. Hppener (Eindhoven University of Technology) prof.dr.ir. R.A.J. Janssen (Eindhoven University of Technology) prof.dr. B.J. Ravoo (Westflische Wilhelms-Universitt Mnster) prof.dr. N.D. Spencer (Eidgenssische Technische Hochschule Zrich)
FFrr MMuuttttii uunndd VVaattii
DDuu uunndd iicchh:: WWiirr ssiinndd eeiinnss..
IIcchh kkaannnn ddiirr nniicchhtt wweehhttuunn,, oohhnnee mmiicchh zzuu vveerrlleettzzeenn..
TTaabbllee ooff CCoonntteennttss
Chapter 1 Chemical modification of self-assembled monolayers by surface reactions 1 1.1. Introduction 2 1.2. Nucleophilic substitution 3 1.3. Click chemistry 8 1.3.1. Click chemistry on azide terminated substrates 9 1.3.2. Click chemistry on acetylene terminated substrates 11 1.4. Metallo-supramolecular modification 15 1.5. Aim and scope of the thesis 21 1.6. References 23 Chapter 2 Chemical surface modification by click chemistry 29 2.1. Introduction 30 2.2. Clicking under conventional reaction conditions 31 2.3. Clicking under microwave heating 36 2.3.1. Stability tests on azide terminated silicon substrates under microwave irradiation 36 2.3.2. Microwave-assisted surface functionalization by 1,3-dipolar cycloaddition 39 188.8.131.52. Microwave-assisted clicking of propargyl alcohol onto azide terminated silicon substrates 41 184.108.40.206. Microwave-assisted clicking of an acetylene functionalized poly(2-ethyl-2-oxazoline) onto azide terminated silicon substrates 43 220.127.116.11. Comparison with reactions under conventional heating 44 2.4. Conclusions 45 2.5. Experimental details 45 2.6. References 49 Chapter 3 Combination of different chemical surface reactions 53 3.1. Introduction 54 3.2. Nucleophilic substitution reactions 54 3.2.1. Nucleophilic substitution of bromine by propargylamine 55 3.2.2. Nucleophilic substitution of bromine by an amine functionalized terpyridine 59 3.3. Supramolecular modification of silicon and glass substrates 63 3.4. Conclusions 70 3.5. Experimental details 71 3.6. References 77
Chapter 4 Structuring and functionalization of self-assembled monolayers by electro-oxidation 81 4.1. Introduction 82 4.2. Local anodic oxidation 83 4.2.1. Local anodic oxidation of substrates coated with organic films 86 4.2.2. Conclusions 90 4.3. Constructive nanolithography 90 4.3.1. Post-modification of the structured surface areas 94 4.3.2. Conclusions 98 4.4. References 98 Chapter 5 Fabrication and functionalization strategies for nanometer-sized surface templates 107 5.1. Introduction 108 5.2. Local anodic oxidation of bromine terminated silicon substrates 109 5.3. Constructive nanolithography on n-octadecyltrichlorosilane terminated monolayers 115 5.4. Conclusions 121 5.5. Experimental details 121 5.6. References 123 Chapter 6 The preparation of patterned polymer brushes onto chemically active surface templates 125 6.1. Introduction 126 6.2. Surface-initiated atom transfer radical polymerization 127 6.3. Surface-initiated ring-opening polymerization 132 6.4. Conclusions 137 6.5. Experimental details 137 6.4. References 139 Summary 142 Samenvatting 145 Curriculum vitae 148 List of publications 149 Acknowledgement 151
CChheemmiiccaall mmooddiiffiiccaattiioonn ooff sseellff--aasssseemmbblleedd mmoonnoollaayyeerrss bbyy ssuurrffaaccee rreeaaccttiioonnss
Abstract The functionalization of solid substrates by self-assembly processes provides the possibility to tailor their surface properties in a controllable fashion. One class of molecules, which attracted significant attention during the last decades, are silanes self-assembled on hydroxyl terminated substrates, e.g. silicon and glass. These systems are physically and chemically robust and can be applied in various fields of technology, e.g. electronics, sensors and others. The introduction of chemical functionalities can be obtained via two methods. One preparation method uses the self-assembly of pre-functionalized molecules, which can be synthesized by different synthetic routes. The second method utilizes chemical surface reactions for the modification of the monolayer. The following chapter will highlight a selection of chemical reactions, which have been used for the functionalization of solid substrates to introduce a wide range of terminal end groups. Parts of this chapter will be published: C. Haensch, S. Hoeppener, U. S. Schubert, in preparation.
1.1. Introduction Self-assembled monolayers (SAMs) have attracted significant attention since their introduction in 1980 by Sagiv. Since then a large variety of self-assembly systems have been studied, such as thiols on gold[2-5] and alkylsilanes on silicon,[6-10] which represent the most popular combinations of self-assembling molecules and substrates. In particular, the self-assembly of silane molecules represents an interesting research area as they form chemically and physically stable covalently attached monolayers on technologically relevant surfaces, in particular silicon and glass.[6,11] The functionalization of surfaces provides the possibility to tailor the surface properties, e.g. wettability, friction, adhesion and conductivity, in a controlled fashion as the modification of the terminal end groups allows the tuning of these properties. These surfaces find many applications in various fields, such as microelectronics, optoelectronics, thin-film technology, protective coatings, chemical sensors, biosensors, nanotechnology, bioactive surfaces, cell adhesion, protein adsorption and others.[13-18] Alkylsiloxane monolayers are usually prepared by a covalent adsorption process of self-assembling molecules, such as trichloro, trimethoxy or triethoxy silanes, onto the solid substrate. The self-assembling molecule consists of three parts: the head group, the alkyl chain and the terminal end group. The head group, i.e., trichloro-, trimethoxy or triethoxy silane, is responsible for the anchoring of the molecule onto the substrate. The alkyl chain provides the stability of the monolayer, due