Spherical periodic mesoporous organosilicas (sph-PMOs) [Elektronische Ressource] : syntheses, characterisation and application in chromatography / vorgelegt von Vivian Rebbin

Informations

• Publié par: justus-liebig-universitat_giessen
• Publié le: 01 janvier 2007
• Nombre de lectures: 29
• Poids de l'ouvrage: 7 Mo

Extrait

SPHERICAL PERIODIC MESOPOROUS
ORGANOSILICAS (sph-PMOs):
SYNTHESES, CHARACTERISATION AND
APPLICATION IN CHROMATOGRAPHY



DISSERTATION


Zur Erlangung des Doktorgrades
des Fachbereichs 08 Chemie und Biologie
der Justus-Liebig-Universität Giessen



vorgelegt von
Vivian Rebbin
aus Hamburg





Giessen 2006 Die vorliegende Arbeit entstand in der Zeit von Mai 2001 bis Dezember 2006 am Institut für
Anorganische und Analytische Chemie der Justus-Liebig-Universität Giessen in der
Arbeitsgruppe von Prof. Dr. Michael Fröba.




























Gutachter: Prof. Dr. Michael Fröba rof. Dr. Siegfried Schindler

















Wenn Du ein Schiff bauen willst,
dann trommle nicht Männer zusammen,
um Holz zu beschaffen, Aufgaben zu vergeben
und die Arbeit einzuteilen,


sondern lehre sie die Sehnsucht nach dem weiten, endlosen Meer.

(Antoine de Saint-Exupéry)


Für meine Eltern












































Contents

1 1 Introduction
1.1 Ordered mesoporous silica materials 2
1.2 Organic-inorganic hybrid materials 5
1.2.1 Post-synthetic functionalisation of pristine silicas (“grafting”) 6
1.2.2 Co-condensation 7
1.2.3 Periodic mesoporous organosilicas (PMOs) 9
1.2.3.1 Synthesis of PMOs with ionic surfactants (alkyltrialkylammonium- and 10
cetylpyridinium halides)
1.2.3.2 Synthesis of PMOs with non-ionic surfactants 17
1.2.3.3 PMOs synthesised with tris-/multi-silylated precursors 21
1.2.3.4 PMOs and other organic-inorganic hybrid materials synthesised with 22
mixtures of different (organo)silica precursors
1.3 Spherical (organically modified) mesoporous silica particles 24
1.4 periodic mesoporous organosilica particles (sph-PMOs) 28
1.5 Aim of this work 29

32 2 Characterisation methods
2.1 Powder X-ray diffraction (P-XRD) 32
2.2 Nitrogen physisorption 32
2.3 Raman spectroscopy 34
2.3.1 Microreactor experiments
2.3.1.1 Micromachining and reactor assembly 34
2.3.1.3 Measurements of the adsorption solvents 35
2.3.2 Raman spectroscopic measurements of powder samples 36
2.4 Nuclear magnetic resonance spectroscopy (NMR) 36
2.5 UV/Vis spectroscopy 37
2.6 Optical microscopy (OM) 37
2.7 Scanning electron microscopy (SEM) 37
2.8 Transmission electron microscopy (TEM) 37
2.9 Atomic force microscopy (AFM) 38
2.10 Thermogravimetric analysis combined with mass spectrometry 38
(TG/MS) 2.11 Laser diffraction 38
2.11.1 Fundamentals
2.11.2 Instrumental parameters 42
2.12 In situ small angle X-ray scattering (SAXS) 43
2.12.1 Experimental setup 43
2.12.2 Instrumental parameters 44
2.13 High performance liquid chromatography (HPLC) 45
2.13.1 Chromatographic fundamentals 45
2.13.2 Choice of the elution solvent 49
2.13.3 Filling of the HPLC columns 50
2.13.4 Instrumental parameters 50
2.14 Atomic absorption spectroscopy (AAS) 50

51 3 Syntheses and characterisation
3.1 Samples for heavy metal adsorption: Ethane- and amine-bridged PMOs 51
3.1.1 Synthesis 51
3.1.2 Results 52
3.1.3 Influence of different synthesis parameters 57
3.1.4 Discussion and conclusion 64

3.2 Spherical ethane-bridged particles with an average particle diameter of 70
500 nm
3.2.1 Synthesis 70
3.2.2 Results 70
3.2.2.1 Comparison of the materials synthesised with different surfactants 70
3.2.2.2 Influence of different synthesis parameters 76
3.2.3 Conclusion 81

3.3 Spherical ethane- and phenylene-bridged particles in the size range of 83
10 – 300 µm
3.3.1 Synthesis of spherical ethane-bridged PMOs in the size range of 25-300 µm 83
3.3.2 spherical phenylene-bridged PMOs in the size range of 10-300 83
µm
3.3.3 Results and discussion 83 3.3.3.1 Characterisation of ethane-bridged and phenylene-bridged PMO spheres 83
3.3.3.2 Influence of different synthesis parameters 90
3.3.3.2.1 Ethane-bridged PMO spheres 91
3.3.3.2.2 Phenylene-bridged PMO spheres 95
3.3.4 Conclusion 97

3.4 Spherical phenylene-bridged PMOs in the size range of 5 – 10 µm 100
3.4.1 Synthesis 100
3.4.2 Results 101
3.4.2.1 Comparison of the phenylene-bridged spheres and Nucleosil 50-10
3.4.2.2 Influence of different synthesis parameters 108
3.4.3 Conclusion 113

116 4 Formation mechanism studies
4.1 In situ small angle X-ray scattering (SAXS) experiments 116
4.2 Experimental 120
4.2.1 Synthesis of 2d hexagonal ordered phenylene-bridged PMOs
®4.2.1.1 Structure-directing agent: Pluronic P123 120
®4.2.1.2 Structure directing agent: Brij 76 121
4.3 Results and discussion 121
®4.3.1 Phenylene-bridged PMOs with Pluronic P123 as SDA 121
®4.3.2 s with Brij 76 as SDA 127
4.4 Conclusion 131

132 5Copper adsorption experiments
5.1 Adsorption of heavy metal ions on organic-inorganic hybrid silica 132
materials
5.2 Experimental 135
5.3 Results and discussion 136
5.3.1 Comparison of the adsorber materials 136
5.3.2 Adsorption experiments 139
2+5.3.2.1 Concentration-dependent Cu adsorption
2+5.3.2.2 Time-dependent Cu adsorption 141
5.4 Conclusion 142 146 6 Solvent vapour adsorption
6.1 Solvent sorption experiments 146
6.2 Characteristics of the applied PMO spheres 147
6.3 Results and discussion 147
6.4 Conclusion 154

156 7 Chromatography on spherical phenylene-bridged PMOs
7.1 Chromatography on (functionalised) spherical mesoporous silica 156
particles
7.2 Chromatography on spherical periodic mesoporous organosilicas 160
7.3 Experimental 161
7.3.1 Sieving procedure
7.3.2 Characteristics of the applied materials 163
7.4 Chromatographic experiments 164
7.4.1 Separation of benzene, naphthalene, biphenyl and phenanthrene
7.4.2 Separation of aspartam, BHT and sorbic acid 170
7.4.3 Separation of caffeine, coumarin and vanillin 173
7.5 Conclusion of the separation experiments 178

181 8 Summary

186 9 Zusammenfassung (German Summary)

193 10 References


Appendix I 203
A.I.1 Applied organosilica precursors
A.I.2 Applied structure-directing agents 204

Appendix II 205
A.II.1 Molar ratios of ethane- and amine-bridged samples synthesised with OTAC 205
as SDA
A.II.2 Molar ratios of ethane- and amine-bridged materials synthesised with CTAC 207
as SDA
A.II.3 Nitrogen physisorption data of the samples synthesised with different OTAC 209
concentrations
A.II.4 Variation of the aging temperature and the aging time 210
A.II.5 Variation of the hydrothermal treatment temperature 212
A.II.6 Nitrogen physisorption data of the ethane- and amine-bridged PMOs 213
synthesised with CTAC as SDA
Appendix III 214
A.III.1 Spherical ethane-bridged particles with an average particle diameter of 500 214
nm
A.III.2 Nitrogen physisorption data of the samples synthesised with different 215
ethanol concentrations
Appendix IV 216
A.IV.1 Molar ratios of the ethane-bridged spheres in the size range of 25 – 300 µm 216
A.IV.2 Molar ratios of the phenylene-bridged spheres in the size range of 10 – 300 218
µm
A.IV.3 Ethane-bridged PMOs synthesised with different stirring rates 219
A.IV.4 Ethane-bridged samples synthesised with different pH values 221
A.IV.5 sed with different co-surfactants 222
A.IV.9 Phenylene-bridged PMOs synthesised at different pH values 223
A.IV.10 s synthesised with different shaking intensities 224
Appendix V 225
A.V.1 Spherical phenylene-bridged PMOs in the size range of 5 to 10 µm 225
A.V.2 Investigations of the hydrothermal treatment procedure 227
A.V.3 Phenylene-bridged spherical PMOs synthesised at different pH values 228
A.V.4 Phenylene-bridged spherical PMOs synthesised with different ethanol 229
concentrations A.V.5 Phenylene-bridged samples synthesised with different contents of both 230
SDAs
Appendix VI 231
®A.VI.1 Molar ratios of the phenylene-bridged samples synthesised with Pluronic231
P123 as SDA
®A.VI.2 Molar ratios of the phenylene-bridged samples synthesised with Brij 76 as 231
SDA
Appendix VII 233
2+A.VII.1 Experimental details of the Cu adsorption experiments 233
A.VII.2 Results of the copper adsorption experiments 236
A.VII.3 Results of the washing procedure 238
Appendix VIII 241
A.VIII.1 UV/Vis spectra of the components of the three test mixtures applied for 241
chromatographic tests
A.VIII.2 The Elutropic Series 244
Appendi