Confocal Raman Microscopy

by Dieing, Thomas; Hollricher, Olaf; Toporski, Jan

• ISBN13: 9783642125218
• ISBN10: 3642125212
• Format: Hardcover
• Copyright: 2011-07-29
• Publisher: Springer Verlag

Summary

Confocal Raman Microscopy is a relatively new technique that allows chemical imaging without specific sample preparation. By integrating a sensitive Raman spectrometer within a state-of-the-art microscope, Raman microscopy with a spatial resolution down to 200nm laterally and 500nm vertically can be achieved using visible light excitation. Recent developments in detector and computer technology as well as optimized instrument design have reduced integration times of Raman spectra by orders of magnitude, so that complete images consisting of tens of thousands of Raman spectra can be acquired in seconds or minutes rather than hours, which used to be standard just one decade ago. The purpose of this book is to provide the reader a comprehensive overview of the rapidly developing field of Confocal Raman Microscopy and its applications.

Table of Contents

High-Resolution Optical and Confocal Microscopy	p. 1
Introduction	p. 1
Introduction to Theoretical Considerations in High-Resolution Microscopy	p. 3
Introduction to Confocal Microscopy	p. 3
Electromagnetic Scattering in Optical Systems	p. 4
3D-Intensity Distribution in the Focus	p. 5
Large Aperture Angles	p. 6
Transition to Small Aperture Angles	p. 9
Theory of Image Formation	p. 11
Microscope	p. 11
Confocal Microscope	p. 12
Confocal Raman Microscope	p. 12
Image Formation for Light Scattering	p. 13
Scattering Point	p. 13
Reflection at a Mirror	p. 15
Image Formation for Raman Scattering	p. 16
Raman Emitting Point	p. 16
Raman Emission of a Layer	p. 17
Pinhole Size	p. 18
References	p. 20
Introduction to the Fundamentals of Raman Spectroscopy	p. 21
Introduction	p. 21
Classical Picture of Light Scattering	p. 22
Frequency Dependence of Raman Scattering	p. 22
Classical "Selection Rule" and Comparison to Ir Absorption	p. 24
Scattered Raman Intensity	p. 25
Shortfalls of the Classical Picture	p. 27
Raman Cross-Section Enhancement Mechanisms	p. 27
Resonant Raman Scattering	p. 28
Advantages and Applications of Resonance Raman Scattering	p. 31
Surface-Enhanced Raman Scattering	p. 34
References	p. 40
Raman Instrumentation for Confocal Raman Microscopy	p. 43
Introduction	p. 43
The Development of Raman Microscopes	p. 44
Confocality	p. 45
Throughput of a Confocal Raman Microscope	p. 46
Laser Wavelength	p. 47
Excitation Power	p. 47
Objective	p. 48
Microscope Throughput	p. 48
Coupling Between Microscope and Spectrometer	p. 49
Spectrometer Throughput	p. 49
Gratings	p. 50
Ccd Detector	p. 51
Conclusion	p. 60
References	p. 60
Software Requirements and Data Analysis in Confocal Raman Microscopy	p. 61
Introduction	p. 61
Requirements for Data Acquisition Software	p. 62
Data Acquisition	p. 62
Correlation of Spatial and Spectral Data	p. 63
Description of the Data Sets Acquired in Confocal Raman Microscopy	p. 65
Pre-processing of Raman Spectra	p. 66
Cosmic Ray Removal	p. 66
Smoothing	p. 68
Background Substraction and Subtraction of Reference Spectra	p. 70
Image Generation	p. 72
Univariate Image Generation	p. 72
Multivariate Image Generation	p. 75
Image Masks and Selective Average Calculation	p. 81
Combination of Single Spectra with Multi-spectral Data Sets	p. 82
Basis Spectra	p. 83
Fitting Procedure	p. 83
Combination of Various Images	p. 84
The Law of Numbers	p. 85
Materials and Methods	p. 88
References	p. 89
Nano-spectroscopy of Individual Carbon Nanotubes and Isolated Graphene Sheets	p. 91
Introduction	p. 91
Individual Carbon Nanotubes	p. 92
Phonons	p. 92
Theory	p. 95
Experiment	p. 96
Microscopy	p. 98
Thermography	p. 100
Isolated Graphene Sheets	p. 101
Theory	p. 101
Experiment	p. 102
Charge Distributions	p. 105
Conclusion	p. 107
References	p. 108
Raman Spectroscopy and Confocal Raman Imaging in Mineralogy and Petrography	p. 111
Introduction	p. 111
Raman Spectroscopy and Imaging as a Mineralogy/Petrography Tool	p. 112
Working with Thin Sections	p. 114
Control of Laser Power	p. 116
"Raman Mineralogy" Using Imaging Raman Techniques	p. 119
Mineral Phase Imaging	p. 120
Crystallographic Orientation Imaging	p. 122
Phase Composition Imaging	p. 123
Examples of "Raman Petrography" Applications	p. 124
Raman Analysis of Shocked Minerals	p. 124
Contextual Imaging of Carbonaceous Materials	p. 126
Fluid Inclusions	p. 129
Ancient Terrestrial Carbonaceous Materials	p. 130
Raman Mineralogy in Field Geology. Studies	p. 130
Extraterrestrial Exploration	p. 132
Conclusion	p. 133
References	p. 133
Raman Micro-spectral Imaging of Cells and Intracellular Drug Delivery Using Nanocarrier Systems	p. 137
Introduction	p. 137
Method	p. 140
Data Acquisition	p. 140
Introduction to Data Processing Methods	p. 140
Experimental	p. 144
Results	p. 145
Cell Imaging	p. 145
Drug Delivery Systems	p. 152
Discussion	p. 161
References	p. 162
Confocal Raman Microscopy in Pharmaceutical Development	p. 165
Introduction	p. 165
Vibrational Spectroscopy in Pharmaceutical Development	p. 166
Imaging in Pharmaceutical Development	p. 169
Chemical Imaging in Pharmaceutical Development	p. 172
Confocal Raman Microscopy in Pharmaceutical Development	p. 176
Applications of Confocal Raman Microscopy in Pharmaceutical Development	p. 179
Practical Considerations	p. 179
Investigation of Solid Dosage Forms by Chemical Imaging	p. 185
Conclusions	p. 198
Materials and Methods	p. 198
References	p. 199
Characterization of Therapeutic Coatings on Medical Devices	p. 203
Background	p. 203
Passive Therapeutic Coatings	p. 205
Coating Thickness	p. 205
Swelling of Hydrophilic Gel Coatings	p. 208
Active Therapeutic Coatings	p. 210
Coating Morphology	p. 210
Drug Mixed with Single Polymer: Morphology and Elution	p. 211
Drug Mixed with Two Polymers: Blending and Layering	p. 216
Drug Mixed with Two Polymers: Exposure to Water	p. 219
Drug Mixed with Biodegradable Polymer: Drug Elution with Polymer Degradation	p. 220
Summary	p. 223
References	p. 223
Raman Imaging of Plant Cell Walls	p. 225
Introduction	p. 225
Plant Cell Walls	p. 226
Micro-Raman Spectroscopy of Plant Fibers	p. 227
Plant Cell Wall Imaging by Confocal Raman Microscopy	p. 228
Imaging Cellulose Orientation and Lignin Distribution in Wooden Cell Walls	p. 228
Silica and Cell Wall Composition in Horsetail	p. 232
Outlook	p. 234
Material and Methods	p. 234
References	p. 235
Confocal Raman Imaging of Polymeric Materials	p. 237
Introduction	p. 237
Raman Imaging of Isotactic Polypropylene (iPP)	p. 239
Raman Imaging of Polymer Blends	p. 244
Raman Imaging of Thin Films of the Polymer Blend: Polystyrene (PS)-Ethyl-Hexyl-Acrylate (EHA)	p. 245
Raman Imaging of Thin Films of the Polymer Blend Ethyl-Hexyl-Acrylate (EHA)-Styrene-Butadiene Rubber (Sbr)	p. 247
Raman Imaging of Thin Films of the Polymer Blend Ps-Eha-Sbr	p. 249
Polymer Coatings	p. 251
Acrylic Paints	p. 251
Adhesives	p. 253
Additives in Polymer Matrices	p. 253
Summary	p. 257
References	p. 257
Stress Analysis by Means of Raman Microscopy	p. 259
Introduction	p. 259
Theoretical Background	p. 260
Measuring in Conventional Back-Scattering Configuration	p. 261
Off-Axis Raman Spectroscopy	p. 263
Stress Tensor Analysis in Back-Scattering Raman Microscopy	p. 266
Case Studies	p. 268
3D Raman Spectroscopy Measurements	p. 268
ZnO	p. 271
The Influence of Stress on the Peak Position of Polymers	p. 273
Discussion	p. 276
References	p. 277
Index	p. 279
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