ACKNOWLEDGEMENTS
TABLE OF CONTENT ................................................ i
ABBREVIATIONS ................................................. vii
1 OBJECTIVES, MOTIVATION AND JUSTIFICATION .................... 1
2 BACKGROUND AND STATE OF THE ART ............................ 7
2.1 NANOMATERIALS .............................................. 7
2.1.1 General Properties and Characteristics .............. 8
Mechanical Properties .................................... 9
Thermal Properties ....................................... 9
Magnetic Properties ..................................... 10
Electrical and Optical Properties ....................... 10
2.1.2 Nanoparticles Synthesis ............................ 11
Sol-Gel (Aqueous and Non-Aqueous) ....................... 12
Solvothermal / Hydrothermal ............................. 14
Seed-Mediated Growth ................................... 16
2.1.3 Special Nanostructures ............................. 17
2.1.4 Nanocomposites Preparation ......................... 20
2.2 PIEZOELECTRICS ............................................ 22
2.2.1 General Concept and Properties ..................... 22
2.2.2 Barium Titanate - BaTiO3 ........................... 26
2.2.3 Size Effect in Piezoelectrics/Ferroelectrics ....... 30
2.3 OPTICAL POLYMERS .......................................... 36
PMMA - Properties and Preparation ......................... 38
PDMS - Properties and Preparation ......................... 40
2.4 LIGHT - MATTER INTERACTION ................................ 44
2.4.1 Light - General Properties ......................... 44
2.4.2 Interaction with Matter ............................ 46
2.4.3 Propagation and Transmission ....................... 48
Refraction .............................................. 49
Scattering .............................................. 50
Materials Classification According its Transmittance .... 51
2.4.4 Polarization and Refractive Index .................. 51
2.5 REFRACTIVE INDEX MODIFICATION - STATE OF THE ART .......... 59
Composition Change ........................................ 60
Chemical Stimulus ......................................... 64
Thermal Stimulus .......................................... 64
Photonic Stimulus ......................................... 64
Electrical Stimulus ....................................... 65
Mechanical Stimulus ....................................... 69
3 EXPERIMENTAL SECTION ...................................... 70
3.1 CHEMICALS AND REAGENTS .................................... 70
3.2 EXPERIMENTAL PROCEDURE .................................... 71
3.2.1 Synthesis of Nanoparticles ......................... 71
3.2.1.1 ВаТiO3 from Ba(OH)2-8H20 and TiO2 Nanoparticles
(Nanoparticle Conversion) ............................. 71
3.2.1.2 ВаТiO3 from Ba(OH)2-8H2O and Titanium (IV)
Isopropoxide (Alkoxide-Hydroxide) ..................... 74
3.2.1.3 ВаТiO3 from Barium Oleate and Titanium (IV)
Isopropoxide (Alkoxide-Oleate) ........................ 77
3.2.1.4 ВаТiO3 from Ва(ОН)2-8H2O and Ti(OH)62-
Titanium (IV) Isopropoxide (Modified
Alkoxide-Hydroxide) ................................... 80
3.2.1.5 ВаТЮз from Ba(OHfc Anhydrous and Titanium
(IV) Isopropoxide (Alkoxide- Anhydrous Hydroxide)
(Urchin Like) ......................................... 83
3.2.1.6 ВаТiO3 by Seed - Growth ........................ 90
3.2.1.6.1 Growth by Alkoxide - Hydroxide Approach .... 91
3.2.1.6.2 Growth by Modified Alkoxide - Hydroxide
Approach ............................................ 92
3.2.1.6.3 Growth by Alkoxide - Anhydrous Hydroxide
Approach ............................................ 93
3.2.2 Surface Modification of Nanoparticles (Ex-Situ) .... 95
3.2.3 Preparation of Nanocomposites ...................... 97
3.2.3.1 PMMA-BaTiO3_OA ................................. 97
3.2.3.2 PMMA-BaTiO3_R-PO(OH)2 .......................... 99
3.2.3.3 PMMA_R-PO(OH)2- ВаТiO3 ........................ 101
3.2.3.4 PDMS-ВаTiO3_ОА ................................ 103
3.3 CHARACTERIZATION TECHNIQUES ............................ 105
3.3.1 Dynamic Light Scattering (DLS) .................... 105
3.3.2 Fourier Transform Infrared Spectroscopy (FTIR) .... 106
3.3.3 Nuclear Magnetic Resonance Spectroscopy
(Solution NMR) .................................... 106
3.3.4 Powder X-Ray Diffraction (XRD) .................... 106
3.3.5 Raman Spectroscopy ................................ 107
3.3.6 Scanning Electron Microscopy (SEM) ................ 107
3.3.7 Spectroscopic Ellipsometry ........................ 108
3.3.8 Thermogravimetric-Differential Thermal Analysis
(TGA - DTA) ....................................... 111
3.3.9 Transmission Electron Microscopy (ТЕМ) ............ 111
3.3.10 UV-Vis Spectroscopy ............................... 111
3.3.11 Zeta-Potential .................................... 112
4 RESULTS AND DISCUSSION ................................... 113
4.1 SYNTHESIS OF NANOPARTICLES ............................... 113
4.1.1 BaTiO3 from Ba(OH)2-8H2O and TiO2 Nanoparticles
(Nanoparticle Conversion) .............................. 114
Educt Concentration .................................... 114
Hydrothermal Temperature and Length .................... 118
4.1.2 BaTiO3 from Ba(OH)2-8H2O and Titanium (IV)
Isopropoxide (Alkoxide-Hydroxide) ...................... 126
Oleic Acid Concentration ............................... 128
Delaying on the Addition of Oleic Acid ................. 134
Educt Concentration andSolvothermal Length ............. 137
Solvothermal Temperature and Length .................... 141
4.1.3 BaTiO3 from Barium Oleate and Titanium (IV)
Isopropoxide (Alkoxide-Hydroxide/Oleate) ............... 145
Solvent, Oleate and Precipitation ...................... 146
Educt Concentration .................................... 157
Solvothermal Temperature and Length .................... 163
4.1.4 BaTiO3 from Ba(OH)2-8H2O and Ti(OH)62-
(from Ti(O-iPr)4) (Modified Alkoxide-Hydroxide) ........ 168
Proof of Concept (Temperature) ......................... 169
Titanium to KOH Ratio .................................. 171
Precipitation Temperature and Length ................... 175
Solvothermal Temperature and Length .................... 179
4.1.5 BaTiO3 from Ba(OH)2 Anhydrous and Titanium (IV)
Isopropoxide (Alkoxide- Anhydrous Hydroxide) (Urchin
Like) .................................................. 189
Solvothermal Conditions (temperature and length) and
Acetone Amount ......................................... 190
Educt Concentration .................................... 208
Short Solvothermal Treatments (200°C, <3 Hours) ........ 212
Barium Hydroxide Alone ................................. 215
Titanium (IV) Isopropoxide Alone ....................... 221
No Solvothermai Treatment .............................. 223
4.1.6 BaTiO3 by Seed - Growth ........................... 230
4.1.6.1 Growth by Alkoxide - Hydroxide Approach ....... 232
Reaction Time (Constant Seed Concentration) .......... 232
Seed Concentration (Constant Educt Concentration) .... 235
Multi-Step Growth - 80°C ............................. 238
Multi-Step Growth - 150°C ............................ 241
4.1.6.2 Growth by Modified Alkoxide - Hydroxide
Approach ............................................. 244
Seed Concentration ................................... 244
Reaction Time (Constant Seed Concentration) .......... 247
4.1.6.3 Growth by Alkoxide - Anhydrous Hydroxide
Approach ............................................. 250
4.2 GRAPHICAL SUMMARY OF NANOPARTICLES ....................... 255
4.3 SURFACE MODIFICATION OF NANOPARTICLES .................... 259
4.4 PREPARATION OF NANOCOMPOSITES ............................ 264
4.4.1 Poly(methyl methacrylate) (PMMA) Based
Nanocomposites ......................................... 267
Modification with Oleic Acid - PMMA Solution (Glass
Substrates) ............................................ 268
Modification with Phosphonic Acid - PMMA Solution
(Brass Substrates) ..................................... 273
Modification with Acrylic Acid - PMMA Solution &
Phosphonate Terminated PMMA (Brass Substrates) ......... 278
Modification with Acrylic Acid & Octylamine - PMMA
Solution & Phosphonate Terminated PMMA (Stainless
Steel Substrates) ...................................... 284
4.4.2 Polydimethylsiloxane (PDMS) Based Nanocomposites .. 290
Modification with Oleic Acid - PDMS In-situ
Polymerization (Glass Substrates) ...................... 291
Modification with Oleic Acid - PDMS In-situ
Polymerization (Stainless Steel Substrates) ............ 294
4.5 GLOBAL ANALYSIS ..................................... 299
5 CONCLUSIONS AND OUTLOOK .................................. 310
REFERENCES .................................................... 320
APPENDIX ...................................................... 341
Nanoparticle Conversion .................................. 342
Alkoxide-Hydroxide ....................................... 343
Alkoxide-Hydroxide Oleate ................................ 350
Modified Alkoxide-Hydroxide .............................. 354
Alkoxide- Anhydrous Hydroxide (Urchin Like) .............. 358
Seed-Growth (Alkoxide-Hydroxide) ......................... 369
Seed-Growth (Modified Alkoxide-Hydroxide) ................ 373
Seed-Growth (Alkoxide- Anhydrous Hydroxide - Urchin
Like) .................................................... 376
Preparation of Nanocomposites ............................ 378
Versicherung .................................................. 383
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