Formulation and characterization of new innovative colloidal systems involving ionic liquids for the application at high temperatures [Elektronische Ressource] / vorgelegt von Stefan Thomaier

Informations

• Publié par: universitat_regensburg
• Publié le: 01 janvier 2009
• Nombre de lectures: 9
• Langue: English
• Poids de l'ouvrage: 8 Mo

Extrait

Formulation and Characterization of New
Innovative Colloidal Systems Involving
Ionic Liquids for the Application
at High Temperatures


Dissertation
zur Erlangung des Grades
Doktor der Naturwissenschaften (Dr. rer. nat.)

Naturwissenschaftliche Fakultät IV
Chemie und Pharmazie
Universität Regensburg






vorgelegt von
Dipl.-Chem.
Stefan Thomaier
Regensburg 2009




















Promotionsgesuch eingereicht am : 08.04.2009
Tag des Kolloquiums: 13.05.2009

Die Arbeit wurde angeleitet von: Prof. Dr. Werner Kunz

Prüfungsausschuß:
Prüfungsvorsitzender: Prof. em. Dr. Dr. h. c. Josef Barthel
1. Gutachter: Prof. Dr. Werner Kunz
2. Gutachter: Prof. em. Dr. Georg Schmeer
3. Prüfer: Prof. em. Dr. Jörg Daub




For my family and Susanne









Acknowledgements
The present PhD thesis was performed at the Institute of Physical and Theoreti-
cal Chemistry, University of Regensburg (Germany) and it is my pleasure to thank nu-
merous people, who became involved in many different ways.
First of all, I would like to thank my PhD supervisor Prof. Dr. W. Kunz, for giv-
ing me this interesting subject, many valuable discussions, and providing me the best
scientific support.
Further, I appreciate Dr. D. Touraud for the helpful discussions concerning the
ionic liquid microemulsions and his continuous interest in my studies. I am grateful to
Dr. Rainer Müller, Prof. Dr. H.-J. Gores, Prof. Dr. R. Buchner and their co-workers,
who supported this work by enabling the usage of their equipment.
Particular thanks are addressed to Dr. U. Keiderling and Dr. I. Grillo, my local
contacts at the HMI Berlin (Germany) and ILL Grenoble (France), respectively, who
helped me in performing the SANS experiments. I extend my thanks to Dr. B. Smarsly
and his co-workers, Max Planck Institute of Colloids and Interfaces (Golm, Germany),
for giving me the opportunity to perform SAXS measurements at their workgroup.
Further, I want to show apreciation to Dr. R. Neueder and Dr. H. Preu for the
good introduction to the field of electrical conductivity and light scattering, respec-
tively.
I am also very grateful to all of my colleagues, who have constructed a very
friendly atmosphere for working. I give my acknowledgement especially to Dipl.-Chem.
O. Zech for the good collaboration in the field of colloidal ionic liquid systems, to col-
leagues Dipl.-Chem. B. Ramsauer, Dipl.-Chem. C. Schreiner, and W. Simon for their
friendship and their general cooperativeness. Additionally, I want to thank Dr. S. Jor-
dan, Dr. C. Blattner, and Dr. J. Kröner for the wonderful time I had with them and for
helping me whenever I needed it, especially at the beginning of my PhD thesis.
My special thanks are given to my family, my girl friend Susanne, and to all of
my friends, who encouraged me and understood my work. Without their support, it
would have been impossible for me to finish this thesis. Table of Contents

I. Introduction .................................................................................................. 1
1.1 Bibliography.........................................................................................9
II. Fundamentals............................................................................................. 20
1 Ionic liquids........................................................................................................ 20
1.1 General aspects...................................................................................20
1.2 Evolution of ionic liquid development............................................... 23
1.3 Concepts of ionic liquid synthesis...................................................... 24
1.4 Bulk physical and chemical properties 28
1.4.1 Phase transition (melting point, glass point, thermotropy)................. 28
1.4.2 Vapour pressure & thermal stability................................................... 30
1.4.3 Viscosity.............................................................................................31
1.4.4 Density & molar volume..................................................................... 32
1.4.5 Surface tension....................................................................................33
1.4.6 Refractive index & polarizability ....................................................... 34
1.4.7 Polarity & solubility strength.............................................................. 34
1.4.8 Acidity & coordination ability............................................................ 36
1.5 Toxicity & biological activity 36
1.6 Applications........................................................................................37
1.7 Bibliography.......................................................................................40
2 Colloidal systems ................................................................................................ 54
2.1 Amphiphiles - surfactants................................................................... 54
2.2 Adsorption of surfactants at the liquid-gas interface.......................... 55 Table of contents ii
2.2.1 Gibbs adsorption theory ......................................................................56
2.2.2 Efficiency & effectiveness of surface tension reduction.....................60
2.2.3 Efficiency of Adsorption: Free Energy of adsorption.........................61
2.3 Self-assembly of surfactants in solution: micelles..............................63
2.3.1 Critical micelle concentration (cmc) ...................................................65
2.3.2 Influence of surfactant structure on the cmc .......................................66
2.3.3 Temperature dependence of surfactant solubility ...............................67
2.3.4 Structure & shape of micelles: packing parameter..............................69
2.3.5 Models of surfactant aggregation........................................................73
2.3.6 Non-aqueous solvents: Solvophobic effect, Gordon parameter, cohe-
sion energy density, internal pressure.................................................77
2.4 Colloidal forces...................................................................................81
2.4.1 Van-der-Waal forces ...........................................................................
2.4.2 Electric double-layer forces ................................................................83
2.4.3 DLVO theory.......................................................................................85
2.4.4 Hydration forces..................................................................................86
2.5 Microemulsions...................................................................................87
2.5.1 Phase diagrams and phase evolution of microemulsions....................88
2.5.2 Curvature energy model - Understanding the phase behaviour of mi-
croemulsions .......................................................................................90
2.5.3 Electrical conductivity of microemulsions: The Microstructure.........93
2.6 Bibliography99
III. Synthesis .....................................................................................................108
1 Chemicals..........................................................................................................108 Table of contents iii
2 Analytics ........................................................................................................... 109
3 Synthesis of the used ionic liquids................................................................... 110
3.1 1-alkyl-3-methylimidazolium chlorides...........................................110
3.1.1 1-dodecyl-3-methylimidazolium chloride (C mimCl) ....................12
3.1.2 1-tetradecyl-3-methylimidazolium chloride (C mimCl) ................. 111 14
3.1.3 1-hexadecyl-3-methylimidaz mimCl)................. 112 16
3.2 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF ) ........... 113 4
3.2.1 1-butyl-3-methylimidazolium chloride (bmimCl)............................ 113
3.2.2 1-butyl-3-methylimidazolium (bmimBF )............ 114 4
3.3 Ethylammonium nitrate (EAN) ........................................................ 115
3.4 Bibliography.....................................................................................115
IV. Experimental............................................................................................. 117
1 Density .............................................................................................................. 117
1.1 General aspects.................................................................................117
1.2 Principle............................................................................................
1.2.1 Apparent Molar Volumes of Surfactants .......................................... 118
1.3 Instrumentation118
1.4 Sample preparation & measurement procedure ............................... 119
2 Surface tension...