Wet chemical synthesis and characterization of organic, TiO_1tn2 multilayers [Elektronische Ressource] / vorgelegt von Aleksandar Tucić

Srot

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• Publié par: universitat_stuttgart
• Publié le: 01 janvier 2008
• Nombre de lectures: 8
• Langue: English
• Poids de l'ouvrage: 9 Mo

Extrait

Max-Planck-Institut für Metallforschung
Stuttgart










Wet Chemical Synthesis and Characterization of
Organic/TiO Multilayers 2

Aleksandar Tuci ć















Dissertation

an der
Universität Stuttgart


Bericht Nr. 212

Januar 2008




















































Wet Chemical Synthesis and Characterization of
Organic/TiO Multilayers 2



Dissertation


Von der Fakultät Chemie der Universität Stuttgart

zur Erlangung der Würde eines

Doktors der Naturwissenschaften (Dr. rer. nat.)

genehmigte Abhandlung




Vorgelegt von

Aleksandar Tuci ć
Aus Belgrad, Serbien




Hauptberichter : Prof. Dr. rer. nat. Fritz Aldinger

Mitberichter : Priv.-Doz. Dr. rer. nat. Joachim Bill

Tag der mündlichen Prüfung : 09.01.2008



Institut für Nichtmetallische Anorganische Materialien der Universität Stuttgart

Max-Planck-Institut für Metallforschung, Stuttgart

Pulvermetallurgisches Laboratorium


2008
Acknowledgements

In the following, I would like to thank the people who contributed to the completion of
this work:
My supervisor, Prof. Dr. Fritz Aldinger, for giving me the opportunity to work in PML,
his guidance and his confidence in the forthcoming of this thesis.
Priv.-Doz. Dr. Joachim Bill, my group-leader and ‘Mitberichter’, who introduced me to
the topic of Bioinspired Materials, for providing me a lot of help during the work and
discussion of results, and patience in reading and correcting of the manuscript.
Prof. Dr. Eric J. Mittemeijer for taking over the ‘Prüfungsvorsitzender’ for my final
examination.
I am also grateful to:
Dr. Rudolf Hoffmann for his numerous helpful suggestions during the experimental
work, for a lot of scientific discussions which we had and final critical reading of the
proof-manuscript.
Dr. Žaklina Burghard for implementing and performing of nanoindentation
measurements, discussion of results and reading the manuscript concerning the
chapter of mechanical properties.
Dr. Vesna Šrot for STEM and Dr. Paul Bellina for HRTEM investigations, as well the
interpretation of results.
Dr. L. Jeurgens and B. Siegle for support in AES investigations.
Dr. L. Pitta-Bauermann for performing QCM measurements and discussion of results.
J. Bartholome and P. Gerstel for precious help in laboratory work.
H. Labitzky and S. Künemann for assistance in SEM investigations.
Dr. P. Lampeter and Dr. U. Wezel for assistance in XRD.
M. Kelsch and U. Eigenthaler for support in FIB preparation of TEM specimens.
All members of PML for providing friendly working atmosphere, many beneficial work
and support in solving all kind of problems.
All my friends from MPI and Stuttgart who made my social life in Germany pleasant
and enjoyable.
Finally, my special thanks to Dr. Hans-Georg Libuda, not only for organizing and
coordinating the IMPRS-AM, but also for his precious help, understanding, support
and friendship during my stay in MPI.

Table of contents

1Abstract ………………………………………………………………….………….

6Zusammenfassung……………………………………………………………….
111. Introduction……………………………………………………………………….

142. Literature overview ……………………………………………………………
2.1. Biomineralization and bio-inspired processing ………………………….…. 14
2.2. Wet chemical processing……………………………………………………... 21
2.3. Deposition of oxide films …………………………………………….............. 22
2.4. Deposition of TiO thin films ………………………………………………….. 242
2.5. Layer-by-layer deposition of polyelectrolytes……………………………….. 25

283. Experimental methods……………………………………………….............
3.1. Film deposition ………………………………………………………………… 28
3.1.1. Substrate preparation …………………………………………………… 28
3.1.2. Deposition of polyelectrolyte layers …………………………………… 28
3.1.3. Deposition of TiO layers ……………………………………………….. 2924. Deposition of PE/TiO multilayers …………………………………….. 312
3.1.5. Thermal treatment……………………………………………………….. 31
3.2. Characterization methods ……………………………………………………. 32
3.2.1. Auger electron spectroscopy (AES) …………………………………… 32
3.2.2. Atomic force microscopy (AFM) …………………………………….…. 32
3.2.3. X-ray diffraction (XRD) ………………………………………………….. 32
3.2.4. Scanning electron microscopy (SEM) ………………………………… 33
3.2.5. Transmission electron spectroscopy (TEM) ………………………….. 33
3.2.5.1. Preparation of cross-sectional TEM specimens………………… 34
3.2.5.2. Focused ion beam (FIB) preparation of cross-sectional TEM
specimens ……………………………………………………….…. 36
3.2.6. Quartz crystal microbalance (QCM) measurements .......................... 38
3.2.7. Nanoindentation.................................................................................. 39


434. Results and discussion ……………………………………………………...
4.1. Deposition of TiO films ……………………………………………………..... 432
4.1.1. Liquid flow vs. static deposition ……………....................……………. 43
4.1.2. Influence of the film thickness on the film roughness …………......... 45
4.1.3. Influence of the deposition temperature and the composition of the
precursor solution on the thickness and morphology of films……….. 47
4.1.4. XRD investigations ……………………………………………………… 56
4.2. Synthesis of polyelectrolyte layers obtained via the layer-by-layer
deposition technique and their characterization……………………………. 59
4.2.1. Thickness measurements ………………………………………………. 59
4.2.1.1. QCM measurements………………………………………………. 592.1.2. AFM measurements ………………………………………………. 61
4.2.1.3. TEM cross-section measurements ………………………………. 62
4.2.1.4. UV/VIS spectroscopy measurements ………………………….. 63
4.2.1.5. Thickness of PE films……………………………………………… 64
4.2.2. Morphological characterization of the PE layers……………………… 65
4.3. Deposition of TiO films on modified surfaces ……………………………... 692
4.4. Synthesis and characterization of PE/TiO multilayers ………………….... 732
4.4.1. Characterization of the topography of PE/TiO multilayers by AFM .. 732
4.4.2. Composition of PE/TiO multilayers ................................................. 752
4.4.3. Microstructure of PE/TiO multilayers ............................................... 772
4.4.4. Crystallinity of PE/TiO............................ 872
4.5. Mechanical properties of the PE/TiO multilayers ……………………….... 932
4.5.1. Influence of residual water on the mechanical properties of the TiO 2
layers……………………………………………………………………… 95
4.5.2. Influence of the incorporation of the organic phase on the
mechanical properties of the TiO layers ……………………………... 982
4.5.3. Influence of the organic/inorganic ratio in the multilayer on the
mechanical properties of the PE/TiO multilayer films……………….. 101 2

1075. Literature………………………………………………………………………….
116Curriculum Vitae …………………………………………………………….........
1
Abstract

The low-temperature deposition of oxide-base thin films from solution induced by
organic templates is inspired by the process of biomineralization. Biominerals, i.e.
inorganic materials synthesized by living organisms, show highly controlled micro-
and nanostructures and in many cases physical properties superior to their manmade
counterparts. In bio-inspired processes thin oxide films can be deposited from
aqueous solutions on organic self-assembled monolayers or polyelectrolytes (PE).
Comparing to other thin films synthesis techniques, like vacuum-based methods,
besides low equipment costs, the chemical bath deposition (CBD) technique needs
much less sophisticated equipments and provides a method for the deposition on
complex shaped and temperature-sensitive substrates. Liquid flow deposition (LFD)
for the synthesis of TiO is based on the continuous flow of a precursor solution along 2
the substrate. Whereas the concentration of the precipitating species within the
reaction solution decreases with increasing deposition time, LFD provides a means to
keep the concentration within the solution constant. Consequently, also the growth
rate of the film is not affected by such aging effects. The deposition technique for the
synthesis of PE layers is based on the electrostatic attraction between op