Optical Phenomenology and Applications (eBook)

Acknowledgements 6
Contents 7
About the Author 14
Concepts and Tools for Optical Sensing in Materials 15
1 Optical Phenomenology for Materials Health Monitoring 16
Abstract 16
1.1 Introduction 16
1.2 Optical Sensing 18
1.2.1 Transduction Strategies 18
1.2.2 Recognition Strategies 19
1.2.2.1 Direct Recognition of Matter Based on Intrinsic Electromagnetic Properties 19
1.2.3 Indirect (Indicator-Based) Recognition 25
1.3 Conclusion 29
References 29
2 Optical Waveguides 32
Abstract 32
2.1 Introduction 32
2.1.1 Optical Waveguides 33
2.2 Sensing of Physical Parameters 34
2.2.1 Interferometric Sensors 34
2.2.2 Fiber Bragg Gratings 35
2.3 Sensing of Chemical Parameters 35
2.3.1 Fiber Materials 36
2.3.2 Sensing Compound 37
2.3.3 Detectors and Light Sources 37
2.4 Conclusion 38
References 38
3 Full Field Imaging 40
Abstract 40
3.1 Introduction 40
3.1.1 Spectral Range and Resolution 41
3.1.2 Broad Band Imaging 42
3.1.3 Multi or Hyperspectral Imaging 42
3.2 Applications in Infrared Imaging 43
3.3 Applications of Imaging in the Visible Range 45
3.3.1 Selective Absorption 45
3.3.2 Imaging Fluorescence 46
3.3.3 Interferometric Imaging 46
3.4 Conclusion 47
References 47
4 Molecular Probes 48
Abstract 48
4.1 Introduction 48
4.1.1 Triggering the Signal 49
4.2 Ratiometric Measurement of Chemosensor Signals 50
4.3 Molecular Origin of the Optical Shifts/Fluorescence on/off Responses 53
4.3.1 Reversible and Irreversible Analyte-Induced Change in Molecular Structure 53
4.3.2 Spectrophotometric Sensing 54
4.3.3 Fluorescence Sensing 54
4.3.4 Fluorescence Turn-off Sensing—Paramagnetic Analytes 54
4.3.5 Fluorescence Turn-on Sensing—Photo-Induced Electron Transfer (PET) Mechanism 55
4.3.6 Luminescence Turn-off Sensing—Collisional Quenching by Triplet Oxygen 56
4.3.7 Fluorescence Resonance Transfer (FRET) Mechanism of Chemosensing 58
4.3.8 Lifetime Measurement Methods 59
4.4 Conclusion 60
References 60
Remote Sensing: Ionic Species and Chemical Signatures 62
5 Remote Sensing of Near Neutral pH Levels 63
Abstract 63
5.1 Introduction 63
5.2 Theory 65
5.2.1 Evanescent Wave Theory 65
5.2.2 Principle of pH Detection 66
5.3 Experimental Work 68
5.3.1 Sensor Cladding Preparation 68
5.3.2 Apparatus 68
5.4 Results and Discussion 70
5.4.1 Transmission Absorption Spectra of Doped Polymer Solutions in Cuvette 70
5.4.2 Absorption Spectra of the Fiber Optic Sensors 70
5.5 Conclusion 71
References 72
6 Optical Sensing of High pH Levels 74
Abstract 74
6.1 Introduction 74
6.2 Porphyrinoids as Halochromic Sensors 76
6.3 Porpholactones as High pH Sensors 78
6.3.1 Synthesis of Porpholactones 78
6.3.2 Colorimetric Base Sensing Using Porpholactones in Organic Solvents 79
6.3.3 Mechanistic Considerations 80
6.3.4 Tuning the Halochromic Sensing Range 81
6.3.5 Chromophore Stability 82
6.3.6 Base Sensing with Porpholactones in Aqueous Solutions: Addition of Surfactants 82
6.3.7 Base Sensing with Porpholactones in Aqueous Solutions: Water-Soluble Porpholactone Derivatives 83
6.3.8 Aqueous Base Sensing Porpholactone Holochromic Sensors Embedded in Polymer Matrixes 85
6.4 Conclusion 89
References 90
7 Sensing of Dissolved Chlorides Using Intrinsic Signals 94
Abstract 94
7.1 Introduction 94
7.2 Intrinsic Sensing of Dissolved Chlorides 95
7.2.1 Effect of Chlorides on Molecular Vibration of Water 96
7.2.2 Experimental Setup and Procedure 97
7.3 Results 98
7.3.1 Measurements of NaCl Concentration Changes Using the Fiber Optic Probe 98
7.3.2 Effect of Temperature 98
7.3.3 Effect of pH Level 99
7.3.4 Eliminating the Effects of Changes in Temperature and pH 99
7.4 Conclusion 101
References 102
In Situ Analysis of Transport Processes in Porous Media 105
8 In Situ Analysis of Moisture in Cement Based Materials 106
Abstract 106
8.1 Introduction 106
8.1.1 Moisture Measurement 108
8.2 Optical Diagnostics 108
8.2.1 Recognition Mechanism 109
8.2.2 Transduction 110
8.3 Experimental Setup 110
8.3.1 Sensor 111
8.3.2 Specimens and Testing 111
8.4 Results and Discussion 111
8.4.1 Drying 112
8.4.2 Capillary Absorption 114
8.4.3 Discussion 114
8.5 Conclusion 116
References 116
9 Subsurface Monitoring of Water in Soil 119
Abstract 119
9.1 Introduction 119
9.2 Optical Spectroscopy 120
9.2.1 Optical Fiber Probe and the Evanescent Field 120
9.2.2 Absorption Spectroscopy 121
9.3 Near-Infrared Signatures 122
9.4 Experimental Work 123
9.4.1 Transport of Water Through Dry Sand 124
9.4.1.1 Experiment: Capillary Moisture Transport Through Dry Sand 126
9.5 Conclusion 128
References 128
10 Sensing Hygrothermal Processes in Calcium Silicate Hydrates 130
Abstract 130
10.1 Introduction 130
10.2 Materials 131
10.2.1 Temperature Sensor 131
10.2.2 Moisture Sensor 132
10.2.3 Cement Samples 132
10.3 Methods 133
10.3.1 Calibration and Monitoring 133
10.3.2 Curing 134
10.4 Conclusion 135
References 135
Subsurface Detection of Water Contaminants 137
11 Sensing Water-Borne Pathogens by Intrinsic Fluorescence 138
Abstract 138
11.1 Introduction 138
11.2 Materials and Methods 140
11.2.1 Microorganisms Used in this Study 140
11.2.2 Fluorescence Spectrometer 141
11.2.3 Sample Preparation for Fluorescence Spectra Measurement 141
11.2.4 Data Processing and Multivariate Analysis 142
11.3 Results 142
11.3.1 3-D Fluorescence Scans of Microorganisms 142
11.3.2 2-D Fluorescence Scanning of Four Bacteria 143
11.3.3 Effect of Growth Stage on the Fluorescence Intensity of Bacteria 144
11.3.4 Evaluation of the Spectra of E. coli, E. faecalis, S. typhimurium and P. aeruginosa 144
11.3.5 Rapid Identification of Bacterial Samples Isolated from Surface Water 148
11.4 Discussion and Conclusion 148
References 150
12 Remote and In Situ Monitoring of Subsurface Liquid Hydrocarbons 153
Abstract 153
12.1 Introduction 153
12.1.1 Prior Work in Subsurface Contaminant Detection 154
12.2 Near-Infrared Measurements of Hydrocarbons 156
12.2.1 Experiments 157
12.2.2 Monitoring the Transport of Mineral Oil Through Partially Saturated Sand 158
12.2.3 Experimental Identification of Characteristic NIR Absorption Spectra of Contaminants 160
12.3 Conclusion 160
References 162
Sensing Gases 164
13 Optical Sensing of Dissolved Oxygen 165
Abstract 165
13.1 Introduction 165
13.2 Sensor Molecules for Sensing Dissolved Oxygen 166
13.2.1 Detection Method: Intensities and Lifetimes 166
13.2.2 Simultaneous Sensing of Temperature 167
13.3 Experimental Results in Dry and Saturated Soil 169
13.3.1 Choice of Sensor Molecule 170
13.3.2 Choice of Host Matrix 170
13.4 Conclusion 171
References 171
14 Molecular Probes for Detection of Subsurface Methane Leaks 173
Abstract 173
14.1 Introduction 173
14.2 Background 174
14.3 Method 175
14.3.1 Oxygen Sensing 176
14.3.2 Transduction Through the Optical Fiber 177
14.3.3 Determination of Leak Location Along Fiber Length 177
14.4 Materials and Testing 177
14.5 Results and Discussion 180
14.6 Conclusion 182
References 182
15 High Fidelity Gas Sensing with Photonic Crystal Fibers 184
Abstract 184
15.1 Introduction 184
15.1.1 Absorption Spectroscopy for Gas Sensing 185
15.1.2 PCF Modes 186
15.2 Sensor Head 187
15.3 Results and Discussions 188
15.4 Conclusion 191
References 191
Imaging Degradation in Materials 193
16 Full Field Imaging of High pH Levels in Concrete 194
Abstract 194
16.1 Introduction 194
16.2 Materials 197
16.2.1 Sensor Compound 197
16.3 Methods 198
16.3.1 Solution Phase Calibration Using Transmittance Spectroscopy 198
16.3.2 Optical Imaging of Pore Solution and Solid Concrete Surfaces 199
16.3.3 Cement Paste and Mortar Sample Preparation 199
16.4 Results and Discussion 200
16.4.1 Spectral Analysis of the TFPLPt Sensor Compound in Solution Phase 200
16.4.2 Imaging of TFPLPt in Solution 201
16.4.3 Imaging of TFPLPt on Hardened Cement Paste 201
16.4.4 Mapping PH Levels in Cured Cement and Mortar Samples After Accelerated Degradation 203
16.5 Conclusions 204
References 204
17 Phase Measurement Interferometry for Mapping Fracture 207
Abstract 207
17.1 Introduction 207
17.2 Method 209
17.2.1 Speckle Interferometry 210
17.3 Materials 211
17.3.1 Wedge Specimens 212
17.4 Calculation of Interface Stresses Induced by Rebar Pullout 212
17.4.1 Edge Rebar Specimens 212
17.4.2 Center Rebar Specimens 215
17.5 Results and Discussions 215
17.5.1 Rebar Specimens 215
17.5.2 Wedge Specimens and Validation of the Hybrid Method 218
17.6 Conclusion 218
References 219
18 Imaging Strain Localization in Fiber Reinforced Materials 221
Abstract 221
18.1 Introduction 221
18.2 Method 222
18.3 Experimental Results 224
18.4 Statistical Analysis 226
18.5 Conclusion 229
References 229
19 Optical Characterization of Translucent Stone Subject to Degradation 230
Abstract 230
19.1 Introduction 231
19.2 Optical Characteristics of Marble 232
19.2.1 Effect on Color 232
19.2.2 Effect on Distinctness of Image and Gloss 234
19.2.3 Effect on Reflectance, Transmittance, Absorbance 235
19.3 Energy Performance 235
19.4 Conclusion 236
References 236
20 Detection of Subsurface Metal Oxidation with Thermal Imaging 238
Abstract 238
20.1 Introduction 238
20.2 Approach 239
20.3 Experiments 240
20.3.1 Instruments 240
20.3.2 Numerical Simulation 245
20.4 Conclusion 248
References 248
21 Sensing Metal Oxidation with Chemical Probes 250
Abstract 250
21.1 Introduction 250
21.2 Sensor Molecules for Infrastructure Corrosion Monitoring 251
21.3 Sensor Molecules for Corrosion Detection of Iron and Zinc 252
21.4 Optical Measurements 255
21.5 Conclusion 256
References 256