Investigations of cooperative interactions in template induced crystallization processes and kinetic studies of nucleation and growth by small-angle neutron scattering [Elektronische Ressource] / Mathias Balz

Yngwie

Informations

• Publié par: johannes_gutenberg-universitat_mainz
• Publié le: 01 janvier 2004
• Nombre de lectures: 9
• Langue: English
• Poids de l'ouvrage: 5 Mo

Extrait

Investigations of
Cooperative Interactions in
Template Induced Crystallization Processes
and
Kinetic Studies of
Nucleation and Growth by
Small-Angle Neutron Scattering




Dissertation
zur
Erlangung des Grades

„ Doktor der Naturwissenschaften ”
am Fachbereich Chemie und Pharmazie
der Johannes Gutenberg – Universität in Mainz


Mathias Balz
geboren in Mainz

Mainz 2004





Die vorliegende Arbeit wurde in der Zeit von Dezember 2000 bis Juni 2004 am Institut für
Anorganische und Analytische Chemie der Johannes Gutenberg – Universität in Mainz
angefertigt.


























Tag der mündlichen Prüfung: 15.07.2004 III



Table of Contents
1. Introduction ___________________________________________________ 1
2. Investigations of Cooperative Interactions in Template Induced
Crystallization Processes ________________________________________ 16
2.1. Crystallization of Vaterite Nanowires by the Cooperative Interaction of Tailor-
Made Nucleation Surfaces and Polyelectrolytes ___________________________16
2.1.1. Introduction _______________________________________________________________ 16
2.1.2. Results and discussion _______________________________________________________ 17
2.1.3. Conclusion ________________________________________________________________ 28
2.1.4. Experimental ______________________________________________________________ 29
2.1.5. References 31
2.2. Crystallization of Strontianite Nanowires on Self-assembled Monolayers in the
Presence of Polyacrylate ______________________________________________34
2.2.1. Introduction _______________________________________________________________ 34
2.2.2. Results and discussion _______________________________________________________ 35
2.2.3. Conclusion ________________________________________________________________ 44
2.2.4. Experimental ______________________________________________________________ 44
2.2.5. References 47
2.3. Controlled Crystallization of CaCO on Hyperbranched Polyglycerol Adsorbed 3
to a SAM ___________________________________________________________50
2.3.1. Introduction _______________________________________________________________ 50
2.3.2. Results and discussion _______________________________________________________ 52
2.3.3. Conclusion ________________________________________________________________ 58
2.3.4. Experimental ______________________________________________________________ 59
2.3.5. References 61
2.4. Crystallization of Vaterite Hemispheres on Carboxymethyl Cellulose Adsorbed
to a SAM ___________________________________________________________63
2.4.1. Introduction _______________________________________________________________ 63 IV



2.4.2. Results and discussion _______________________________________________________ 64
2.4.3. Conclusion ________________________________________________________________ 68
2.4.4. Experimental ______________________________________________________________ 69
2.4.5. References 71
3. Kinetic Studies on Nucleation by SANS ____________________________ 73
3.1. In-Situ Investigation of CaCO Nucleation and Growth in the Presence of the 3
Egg-white Protein Ovalbumin by Small-Angle Neutron Scattering ___________73
3.1.1. Introduction _______________________________________________________________ 73
3.1.2. Theoretical background of small-angle neutron scattering ___________________________ 75
3.1.3. Experimental section ________________________________________________________ 78
3.1.4. Experimental results_________________________________________________________ 80
3.1.5. Interpretation of the SANS results ______________________________________________ 90
3.1.6. Discussion ________________________________________________________________ 99
3.1.7. Summary and conclusions ___________________________________________________ 100
3.1.8. References _______________________________________________________________ 102
3.2. Nucleation and Growth of CaCO Minerals on Biomimetic Templates studied by 3
Small-Angle Scattering ______________________________________________104
3.2.1. Introduction ______________________________________________________________ 104
3.2.2. Results and discussion ______________________________________________________ 104
3.2.3. Conclusion 112
3.2.4. Experimental _____________________________________________________________ 112
3.2.5. References _______________________________________________________________ 114
4. Conclusion __________________________________________________ 115
5. Appendix ____________________________________________________ 118
5.1. Methods and Instrumentation ________________________________________118
5.1.1. Quartz Crystal Microbalance _________________________________________________ 118
5.1.2. Small-Angle Neutron Scattering ______________________________________________ 120
5.1.3. Surface Plasmon Resonance Spectroscopy ______________________________________ 121 Introduction 1
1. Introduction

Biomineralization is the process of formation of inorganic solid materials by living
organisms. The formation of mineralized skeleton structures by living organisms
started about 570 million years ago [1]. Living organisms are able to produce high-
quality mineral structures ranging from the Ångstrom to the centimeter level and
built at ambient temperature and pressure. Corals, crawfish, mussels and snails
create highly complex and extremely stable inorganic materials of partly intriguing
shape that show a vast variety of biological functions as well as remarkable,
unusual and advantageous mechanical properties. Key components in the process
of formation are biological macromolecules, which are intimately associated with
the inorganic minerals leading to so-called biocomposites. These macromolecules
exert control on nucleation, growth, crystal shape, particle size, polymorphic
structure and crystal orientation resulting in physical properties of the biominerals
that are very different compared to those of their synthetic counterparts [2]. The
fact that the mineralization process involves a cellular process and also that the
formation of the organic matrix is genetically controlled, makes it difficult to probe
and mimic these complex systems. Therefore it is not surprising that the process
of biomineralization so far is not well understood in detail [2]. Nevertheless it is
possible to study the biological and chemical aspects by model systems. In
particular, the use of the organic components that mediate the growth of the
mineral, the nucleation process as well as the structure-property-function relations
are of special interest for materials scientists and engineers. Understanding these
processes could enable researchers to imitate the often advantageous properties
of the biominerals and to develop new ideas for the improved design of synthetic
materials.
With the above-named aspects in mind the DFG (Deutsche
Forschungsgemeinschaft) has launched a research project [3] which involves
scientific research groups from biology, biochemistry, inorganic and analytical
chemistry.
Introduction 2
More than 60 different biominerals are known. These include both crystalline and
amorphous materials. The most widespread examples are iron oxide, silica,
calcium phosphate and calcium carbonate [1].
The different types of iron oxides display several varying functions depending on
the living organism. For example, there are molluscs called chitons
(polyplacophora) [4-6] which involve about 1000 species. One feature is their
multi-part shell, another is their impressive mouth, which contains teeth made of
magnetite or other crystalline iron oxides. The chitons are found on intertidal rocks
or under rocks of reefs. They feed on algae, scraping them off rocks and coral
reefs. For this purpose their teeth have to be very tough and hard. The
mineralization process of the teeth is very complex and involves other minerals
such as calcium phosphate and an organic matrix. The process of fabrication of
this high-grade material by a rather primitive mollusc group is not yet understood.
Disclosing this secret could enable scientists to mimick these processes and
manufacture high-grade synthetic magnetite.
Many different animal species, such as pigeons or specific fish species, use the
earth`s magnetic field to orient themselves. In many cases the underlying sensor
is not well known, however it is identified in the so-called magnetotactic bacteria
[7-9], that are able to orientate along geomagnetic field lines. The magnetic
bacteria are to be found at the sediment-water interface both in salt water and
fresh water. Their internal compass needle is made of nano-sized magnetit