Nanoporous hosts for the encapsulation of conductive nanostructured materials [Elektronische Ressource] / von Nikolay Petkov

Nanoporous hosts for the encapsulation of
conductive nanostructured materials






200 nm

























Nikolay Petkov




iDissertation zur Erlangung des Doktorgrades
der Fakultät für Chemie und Pharmazie
der Ludwig-Maximilians-Universität München





Nanoporous hosts for the encapsulation of conductive
nanostructured materials







von
Nikolay Petkov
aus
Sofia
2004





iiErklärung
Diese Dissertation wurde im Sinne von § 13 Abs. 3 bzw. 4 der Promotionsordnung vom
29. Januar 1998 von Herrn Prof. Dr. Thomas Bein betreut.



Ehrenwörtliche Versicherung

Diese Dissertation wurde selbständig, ohne unerlaubte Hilfe erarbeitet.
München, am 17. Februar 2004






(Unterschrift des Autors)

Dissertation eingereicht am 17. Februar 2004



1. Gutachter: Prof. Dr. Thomas Bein
2. Gutachter: Prof. Dr. Helmut Knözinger
Mündliche Prüfung am 22. März 2004






iii









For my Grandfather Boris
and my Family






















ivContents

Contes v

Acknowledgements x

Preface xi

Chapter 1. Introduction to nanoscience and nanotechnology 1
1.1. Nanoscience and nanotechnology 1
1.2. Nanoelectronics 4
1.2.1. Top-down approach 5
1.2.2. Bottom-up 7
1.3. Perspectives 9
Refernces 10

Chapter 2. Introduction to nanoporous materials 11
2.1. Introduction 11
2.2. Surfactant-templated mesoporous materials 12
2.2.1. Definition, nomenclature, and structure 12
2.2.2. Mechanism of formation, properties, and applications 18
2.2.3. Functionalized ordered mesoporous materials 23
2.2.4. Ordered mesoporous films 24
Refernces 29

Chapter 3. Introduction to one-dimensional nanostructures 35
3.1. Introduction 35
3.2. General synthetic routes for the preparation of
one-dimensional nanostructures 35
3.3. General properties of one-dimensional nanostructures 38
3.4. Synthesis and properties of carbon nanotubes 40
Refernces 44

vChapter 4. Characterisation techniques for nanostructured materials 47
4.1. Introduction 47
4.2. X-ray diffraction (XRD) 47
4.3. Infrared and Raman spectroscopy 53
4.4. Nitrogen-sorption measurements 54
4.5. Electron microscopy 58
4.6. Other characterization techniques 60
4.6.1. Dynamic light scattering (DLS)
4.6.2. Thermogravimetric analysis (TGA) 61
Refrnces 61

Chapter 5. Synthesis and characterization of mesoporous powders
with different morphologies 63
5.1. Introduction 63
5.2. Experimental 65
5.2.1. Synthesis of MCM-48 spheres 65
5.2.2. SBA-15 rods 66
5.2.3. Synthesis of mesostructured monoliths 66
5.2.4. Calcination procedures 67
5.2.6. Characterization 68
5.3. Results and Discussion
5.3.1. Mesophase structure and thermal stability 68
5.3.2. Sorption properties and surface morphology 80
5.4. Conclusions and perspectives 87
Refrnces 88

Chapter 6. Preparation and characterization of ordered mesoporous films 90
6.1. Introduction 90
6.2. Experimental 91
vi6.2.1. Preparation of ordered mesoporous films 91
6.2.2. Characterization of the mes 92
6.3. Results and discussion 93
6.3.1. Mesophase structure - influence of the relative humidity,
composition of the coating solution and post-synthesis thermal treatments 93
6.3.1.1. CTABr-templated mesoporous films 93
6.3.1.2. Pluronic123-templated mes 105
6.3.2. Sorption properties of the mesoporous films – N -sorption studies 2
with a QCM device 111
6.3.3. Surface morphology and thickness of the mesoporous films 115
6.4. Conclusions and Perspectives 118
References 119

Chapter 7. Growth of carbon nanotubes by catalytic decomposition of acetylene on
Fe-containing mesoporous films 120
7.1. Introduction 120
7.2. Experimental 121
7.2.1. Preparation of Fe-containing mesoporous films and monoliths 121
7.2.2. Growth of carbon nanotubes 123
7.2.3. Characterization 123
7.3. Results and Discussion
7.3.1. Nature of precursor species in Fe-containing coating solutions 123
7.3.2. Mesophase structure and surface morphology of Fe-containing
mesoporous films and monoliths 126
7.3.3. Growth of carbon nanotubes 132
7.4. Conclusions and Perspectives 139
References 140

Chapter 8. Growth of carbon filaments in ferrocene-modified SBA-15 rods
and mesoporous thin films 141
8.1. Introduction 141
vii8.2. Experimental 142
8.2.1. Modification of the SBA-15 rods and mesoporous films 142
8.2.2. Growth of carbon filaments 145
8.2.3. Characterization 145
8.3. Results and Discussion 146
8.3.1. Amino- and ferrocene-modified SBA-15 rods 146
8.3.2. Carbon filaments in ferrocene-m 156
8.3.3. Carbon filameodified mesoporous films 161
8.4. Conclusions and Perspectives 169
References 170

Chapter 9. Gold nanostructures in mesoporous SBA-15 rods and mesoporous films
prepared by electroless reduction 172
9.1. Introduction 172
9.2. Experimental 175
9.2.1. Modification of the SBA-15 rods and mesoporous films 175
9.2.2. Preparation of gold nanoparticles 176
9.2.3. Assembly of gold nanoparticles on MPS- and
AEPMS-modified mesoporous materials and electroless reduction 178
9.2.4. Characterization 179
9.3. Results and Discussion 180
9.3.1. MPS- and AEPMS-modified SBA-15 180
9.3.2. Preparation of gold nanoparticles 188
9.3.3. Assembly of gold nanoparticles and electroless reduction of gold in
SBA-15 rods 191
9.3.4. Au nanostructures in MPS-modified mesoporous films 206
9.4. Conclusions and Perspectives 213
References 215

Chapter 10. Preparation of semiconductor PbS nanostructures in functionalized
mesoporous SBA-15 rods and mesoporous thin films 217
viii10.1. Introduction 217
10.2. Experimental 219
10.2.1. Synthesis of PbS nanostructures in functionalized
mesoporous materials 219
10.2.2. Characterization 221
10.3. Results and Discussion 222
10.3.1. PbS nanostructures in SBA-15 rods 222
10.3.2. PbS nanostructures in mesoporous films 225
10.4. Conclusions and Perspectives 229
References 229

Conclusions and Outlook 231

Curriculum Vitae 236

List of Publications 237
ixAcknowledgements

I would like to acknowledge the people who made this work possible and gave me the
opportunity to experience the freedom to explore, to chase ideas, to be excited and
disappointed at the same time.
Prof. Dr. Thomas Bein has provided guidance, ideas, and concepts without
interference, and encouraged creativity and self-confidence that were necessary for the
research work. He also thought me to gain much criticism and scientific liability to my and
other people’s results, and for that I am truly grateful.
The person without whom I would probably never have had a chance to start a
research career is Dr. Svetlana Mintova; for that I am gratefully thankful.
Enjoyable work is never a lonely task. For that one needs not only good colleagues but
also friends. And my list of colleagues that became my friends is long. I would start with Jake
Reder, Ken Yasuda, Norbert Stock, and Jürgen Sauer that were my lab-teachers and who
stayed behind where I was making my first failures and successes. Martin Kuba, Barbara
Fieres, Sing-Jin, and Lea Mühlstein were there to share knowledge, ideas, and results on our
common project. Alex Darga, Stephan Angloher, Sebastian Bauer, Enrica Biemmi, Manoel
Vega, and others with whom I shared creative discussions, cases of bier, long-drinks, and
emotions.
I’d like to thank Prof. Dr. H. Knözinger for being my second reviewer.
Finally, I thank my parents for their love, patience, and reliance. I like to thank my
sister for her intelligence and understanding.
Thanks to all people that believed in me!
x