Ionic liquids in microemulsions [Elektronische Ressource] : a concept to extend the conventional thermal stability range of microemulsions / Oliver Zech
209 Pages
English
Downloading requires you to have access to the YouScribe library
Learn all about the services we offer

Ionic liquids in microemulsions [Elektronische Ressource] : a concept to extend the conventional thermal stability range of microemulsions / Oliver Zech

-

Downloading requires you to have access to the YouScribe library
Learn all about the services we offer
209 Pages
English

Description

Ionic Liquids in Microemulsions – a Concept to Extend the Conventional Thermal Stability Range of Microemulsions Dissertation Presented for the Degree of Doctor of Natural Sciences (Dr. rer. nat.) University of Regensburg Natural Sciences Faculty IV Chemistry & Pharmacy Oliver Zech Regensburg 2010 Official Registration: 27.11.2009 Defense: 15.01.2010 Ph.D. Supervisor: Prof. Dr. Werner Kunz Adjudicators: Prof. Dr. WePD. Dr. Rainer Müller Prof. Dr. Jörg Daub Chair: Prof. em. Dr. Dr. h. c. Josef Barthel Contents Contents Contents................................................................................................................ i Preface ............................................................................................................... vii Constants and Symbols..................................................................................... ix I. Introduction ..............................................................................................- 1 - II. Fundamentals............................................................................................- 5 - 1.

Subjects

Informations

Published by
Published 01 January 2010
Reads 5
Language English
Document size 3 MB

Exrait

Ionic Liquids in Microemulsions – a
Concept to Extend the Conventional
Thermal Stability Range of
Microemulsions







Dissertation Presented for the Degree of
Doctor of Natural Sciences
(Dr. rer. nat.)


University of Regensburg
Natural Sciences Faculty IV
Chemistry & Pharmacy


Oliver Zech
Regensburg 2010



































Official Registration: 27.11.2009
Defense: 15.01.2010
Ph.D. Supervisor: Prof. Dr. Werner Kunz
Adjudicators: Prof. Dr. We
PD. Dr. Rainer Müller
Prof. Dr. Jörg Daub
Chair: Prof. em. Dr. Dr. h. c. Josef Barthel


Contents
Contents
Contents................................................................................................................ i
Preface ............................................................................................................... vii
Constants and Symbols..................................................................................... ix
I. Introduction ..............................................................................................- 1 -
II. Fundamentals............................................................................................- 5 -
1. Ionic Liquids ........................................................................................................... - 5 -
1.1. General aspects and types of ionic liquids........................................................ - 5 -
1.2. Physicochemical properties .............................................................................. - 8 -
1.2.1. Melting points and liquid range of ILs ..................................................... - 8 -
1.2.2. Viscosity and ionic conductivity .............................................................. - 9 -
1.2.3. Solvent properties................................................................................... - 11 -
1.3. Applications.................................................................................................... - 13 -
2. Microemulsions..................................................................................................... - 15 -
2.1. Definition........................................................................................................ - 15 -
2.2. Types of microemulsions and phase behavior................................................ - 16 -
2.2.1. Oil-in-water and water-in-oil microemulsions ....................................... - 16 -
2.2.2. Other structures ...................................................................................... - 18 -
2.2.3. Winsor phase classification .................................................................... - 19 -
2.2.4. Phase diagrams of microemulsions ........................................................ - 21 -
2.2.5. Microemulsions with non-ionic surfactants ........................................... - 22 -
2.2.6. ulsions with ionic surfactants................................................... - 26 -
2.3. Applications.................................................................................................... - 27 -
2.4. Methods to characterize microemulsions ....................................................... - 28 -
2.4.1. Electrical conductivity............................................................................ - 28 -
2.4.2. Viscosity................................................................................................. - 34 -

i Contents
2.4.3. Dynamic light scattering (DLS)..............................................................- 35 -
2.4.4. Small angle scattering (SAS) ..................................................................- 39 -
2.4.5. Other methods.........................................................................................- 49 -
III. Experimental...........................................................................................- 51 -
1. Chemicals...............................................................................................................- 51 -
2. Synthesis.................................................................................................................- 51 -
2.1. Ethylammonium nitrate (EAN).......................................................................- 51 -
2.2. 1-Butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF ])....................- 52 - 4
2.3. hexafluorophosphate ([bmim][PF ])..............- 53 - 6
2.4. 1-Alkyl-3-methylimidazolium chloride ([C mim][Cl], n = 12, 14, 16,18).....- 54 - n
2.5. 1-Ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO ]).........................- 55 - 4
2.6. 2,5,8,11-Tetraoxatridecan-13-oic acid (TOTOA)...........................................- 56 -
2.7. TOTOA alkali salts .........................................................................................- 57 -
3. Experimental methods..........................................................................................- 60 -
3.1. Analytical methods- 60 -
3.2. Electrical conductivity ....................................................................................- 61 -
3.3. Dynamic light scattering .................................................................................- 63 -
3.4. Densities..........................................................................................................- 64 -
3.5. Viscosities .......................................................................................................- 65 -
3.6. Small angle X-Ray scattering (SAXS) ...........................................................- 65 -
3.7. Small angle neutron scattering (SANS)..........................................................- 66 -
IV. Results and Discussion ...........................................................................- 69 -
1. The conductivity of imidazolium-based ionic liquids over a wide temperature
range. Variation of the anion ...............................................................................- 69 -
1.1. Abstract ...........................................................................................................- 69 -
1.2. Introduction.....................................................................................................- 69 -
1.3. Synthesis and sample handling .......................................................................- 70 -
1.4. Results and discussion ....................................................................................- 71 -

ii Contents
1.5. Concluding remarks........................................................................................ - 78 -
2. Microemulsions with an ionic liquid surfactant and room temperature ionic
liquids as polar phase ........................................................................................... - 79 -
2.1. Introduction .................................................................................................... - 79 -
2.2. Investigations at ambient temperature............................................................ - 81 -
2.2.1. Abstract................................................................................................... - 81 -
2.2.2. Sample handling and experimental path................................................. - 82 -
2.2.3. Results and discussion............................................................................ - 82 -
2.2.3.1. Microregions and phase behavior....................................................... - 82 -
2.2.3.2. Conductivity ....................................................................................... - 84 -
2.2.3.3. Viscosity............................................................................................. - 88 -
2.2.3.4. Dynamic light scattering (DLS) ......................................................... - 89 -
2.2.3.5. Small angle X-ray scattering (SAXS) ................................................ - 90 -
2.2.4. Concluding remarks................................................................................ - 97 -
2.3. Ethylammonium nitrate in high temperature stable microemulsions............. - 99 -
2.3.1. Abstract................................................................................................... - 99 -
2.3.2. Sample handling and experimental path................................................. - 99 -
2.3.3. Results and discussion.......................................................................... - 100 -
2.3.3.1. Density.............................................................................................. - 100 -
2.3.3.2. Visual observations - 101 -
2.3.3.3. Solubility of EAN in dodecane......................................................... - 101 -
2.3.3.4. Conductivity ..................................................................................... - 103 -
2.3.3.5. Dynamic light scattering (DLS) ....................................................... - 106 -
2.3.3.6. Small angle neutron scattering (SANS) ........................................... - 109 -
2.3.4. Concluding remarks.............................................................................. - 118 -
2.4. The effect of surfactant chain length on the phase behavior of microemulsions
containing EAN as polar microenvironment............................................................ - 120 -
2.4.1. Abstract................................................................................................. - 120 -
2.4.2. Results and discussion.......................................................................... - 120 -
2.4.2.1. Phase diagrams ................................................................................. - 120 -
2.4.2.2. Density.............................................................................................. - 121 -
2.4.2.3. Conductivity ..................................................................................... - 122 -

iii Contents
2.4.2.4. Viscosity ...........................................................................................- 125 -
2.4.2.5. Dynamic light scattering ...................................................................- 125 -
2.4.3. Concluding remarks ..............................................................................- 126 -
2.5. Biodiesel, a sustainable oil, in high temperature stable microemulsions containing
a low-toxic room temperature ionic liquid as polar phase........................................- 128 -
2.5.1. Abstract .................................................................................................- 128 -
2.5.2. Introduction- 128 -
2.5.3. Results and discussion ..........................................................................- 129 -
2.5.3.1. Phase diagram ...................................................................................- 129 -
2.5.3.2. Visual observations...........................................................................- 130 -
2.5.3.3. Density ..............................................................................................- 131 -
2.5.3.4. Conductivity......................................................................................- 131 -
2.5.3.5. Small angle X-Ray scattering (SAXS) .............................................- 134 -
2.5.3.6. Viscosity ...........................................................................................- 138 -
2.5.4. Concluding remarks ..............................................................................- 138 -
2.6. [bmim][BF ] in high temperature stable microemulsions.............................- 140 - 4
2.6.1. Introduction- 140 -
2.6.2. Results and discussion ..........................................................................- 140 -
2.6.2.1. Conductivity......................................................................................- 140 -
2.6.2.2. Small angle neutron scattering (SANS)............................................- 143 -
2.6.3. Concluding remarks ..............................................................................- 144 -
3. Alkali oligoether carboxylates – a new class of ionic liquids...........................- 146 -
3.1. Abstract .........................................................................................................- 146 -
3.2. Introduction...................................................................................................- 146 -
3.3. Results and discussion ..................................................................................- 147 -
3.3.1. Synthesis ...............................................................................................- 147 -
3.3.2. Conductivity and viscosity....................................................................- 149 -
3.3.3. Electrochemical stability.......................................................................- 152 -
3.3.4. Cytotoxity tests .....................................................................................- 154 -
3.4. Concluding remarks ......................................................................................- 155 -
V. Summary- 157 -

iv Contents
VI. Appendix ............................................................................................... - 163 -
1. List of publications - 163 -
2. Patent....................................................................................................................- 164 -
3. Index of figures..................................................................................................... - 164 -
VII. Literature Cited................................................................................... - 173 -

v Preface
Preface
The work described in this PhD thesis has been carried out at the Institute of Physical and
Theoretical Chemistry, Faculty of Natural Sciences IV, University of Regensburg, between
October 2006 and December 2009 under the supervision of Prof. Dr. W. Kunz. This work
would not have been possible without the help and support of many people, whom I owe a
great dept of gratitude.
First of all I would like to express my sincere gratitude to Prof. Dr. W. Kunz for giving me the
opportunity to work independently, for the interesting subject, valuable discussions and for
financial support.
Furthermore, I am grateful to Dr. D. Touraud for help concerning the formulation of the
microemulsions and the phase diagram interpretation as well as for continuous interest in the
progress of the work. Additionally, I want to thank Prof. Dr. R. Buchner for discussions
concerning the conductivity data of the neat ionic liquids and for critical reading the
corresponding manuscript. I am further grateful to PD Dr. R. Müller, Prof. Dr. A. Pfitzner and
Prof. Dr. H. Gores for providing their equipment for the TGA, DSC and CV measurements,
respectively.
In particular I would like to thank Dr. I. Grillo for her efforts to find the appropriate
equipment for the high temperature SANS measurements and valuable discussions concerning
the interpretation of the SANS data. Further, I would like to express my gratitude to Dr. P.
Bauduin for performing SAXS measurements in Paris and Marcoule and for help with the
data evaluation and interpretation. Moreover, I am grateful to Dr. U. Keiderling and Dr. J.
Jestin for their efforts concerning SANS measurements in Berlin and Paris, respectively.
In addition, I would like to thank my lab colleagues Dr. S. Thomaier and A. Kolodzieski for
the fruitful collaboration in the field of ionic liquids and colloidal systems thereof.
Furthermore, I am grateful to J. Hunger, A. Kolodziejski and R. Klein for critical reading
parts of this manuscripts, innovative ideas and suggestions. Moreover, I want to express my
gratitude to A. Stoppa for the collaboration in the field of conductivity of neat ionic liquids
and to M. Kellermeier, Dr. S. Thomaier, E. Maurer, R. Klein, B. Ramsauer and Dr. C.
Schreiner for their help and support in the field of alkali oligoether carboxylates. Particular
thanks to E. Maurer for performing the cytotoxicity test and Dr. C. Schreiner for the CV
measurements. I am grateful to S. Thomaier, A. Stoppa, J. Hunger and H. Dorfner for the

vii Preface
teamwork concerning the construction of the homemade glovebox and the barbecue,
respectively.
Many thanks to all staff members for the pleasant atmosphere in the laboratory in both a
scientific and private manner. I will especially treasure our hikes in the mountains and the
“good” morning coffee which we had every morning, although the taste was non-stop
miserable and infuriatingly with an extraordinary uniformity.
Apart from that, I am grateful to my colleague M. Dürr, who unfortunately died much too
early, for supporting me during my studies, for his friendship and interest. I will miss his
unique humor a lot.
In particular I would like to thank my parents for their mental and financial support.
Finally, I want to offer my heartfelt thanks to my girlfriend Nina for her understanding and for
encouraging me on all my paths.

viii