Contents
Chapter 1 Overview 1
1.1 Introduction 1
1.2 Characterizing the spatial distribution of adsorbed water in wood 3
1.2.1 Magnetic resonance imaging technique 3
1.2.2 Computed tomography scanning technique 4
1.2.3 Neutron radiography 5
1.2.4 Vibrational spectroscopic imaging techniques 6
1.3 Determining molecular interactions between adsorbed water and wood 7
1.3.1 Near-infrared spectroscopy 7
1.3.2 Nuclear magnetic resonance technique 8
1.3.3 Fourier transform infrared spectroscopy 9
1.3.4 Raman spectroscopy 10
1.4 Future directions 11
References 11
Chapter 2 Quantitative detection of moisture content in heat-treated wood cell walls using micro-FTIR spectroscopy 17
2.1 Introduction 17
2.2 Materials and methods 20
2.2.1 Materials 20
2.2.2 Micro-FTIR spectrometer 20
2.2.3 DVS apparatus 21
2.2.4 Micro-FTIR data processing 22
2.3 Results and discussion 23
2.3.1 Qualitatively analyzing moisture sorption 23
2.3.2 Quantitative analysis of moisture sorption 26
2.4 Conclusions 28
References 29
Chapter 3 Quantitative analysis of moisture sorption in lignin using micro-FTIR spectroscopy 34
3.1 Introduction 34
3.2 Materials and methods 37
3.2.1 Materials 37
3.2.2 Experimental apparatus for micro-FTIR spectral measurement 37
3.2.3 Experimental apparatus for moisture content measurement 38
3.2.4 Micro-FTIR spectral data processing 39
3.3 Results and discussion 40
3.3.1 Quantitative analysis of moisture adsorption in lignin 40
3.3.2 Quantitative evaluation of moisture adsorption in lignin 43
3.4 Conclusions 46
References 46
Chapter 4 Quantitatively characterizing moisture sorption of cellulose using micro-FTIR spectroscopy 51
4.1 Introduction 51
4.2 Experiment section 53
4.2.1 Sample preparation 53
4.2.2 Micro-FTIR spectroscopy apparatus 54
4.2.3 DVS apparatus 56
4.2.4 Spectral data processing 57
4.3 Results and discussion 57
4.3.1 Qualitatively analyzing water adsorption of cellulose nanofiber film 57
4.3.2 Quantitative analysis of water adsorption in cellulose nanofiber film 60
4.4 Conclusions 63
References 63
Chapter 5 Quantitative evaluation of moisture sorption in TEMPO oxidized cellulose using micro-FTIR spectroscopy 69
5.1 Introduction 69
5.2 Materials and methods 72
5.2.1 Materials 72
5.2.2 Experimental apparatus for micro-FTIR spectroscopy measurement 72
5.2.3 Determination of moisture content using DVS apparatus 74
5.2.4 Data processing of micro-FTIR spectra 75
5.3 Results and discussion 75
5.3.1 Quantitative analysis of moisture adsorption in TOCNF 75
5.3.2 Quantitatively evaluating water adsorption of TOCNF 78
5.4 Conclusions 80
References 81
Chapter 6 Molecular association of water with wood cell walls during moisture desorption process examined by micro- FTIR spectroscopy 87
6.1 Introduction 87
6.2 Materials and methods 90
6.2.1 Materials 90
6.2.2 Experimental instrument for micro-FTIR spectral measurement 90
6.2.3 Micro-FTIR spectral data processing 91
6.3 Results and discussion 92
6.3.1 Effective water sorption sites of wood 92
6.3.2 Molecular structure change of water during moisture desorption process 94
6.4 Conclusions 98
References 98
Chapter 7 Molecular association of water with heat-treated wood cell walls during moisture adsorption process examined by micro-FTIR spectroscopy 104
7.1 Introduction 104
7.2 Experimental section 107
7.2.1 Sample preparation 107
7.2.2 Micro-FTIR spectroscopy equipment 108
7.2.3 Data processing 109
7.3 Results and discussion 110
7.3.1 FTIR spectra of the heat-treated wood associated with water molecules 110
7.3.2 The analysis of difference spectra 112
7.3.3 Intermolecular interactions between adsorbed water and the heat-treated wood 113
7.4 Conclusions 121
References 121
Chapter 8 Molecular association of adsorbed water with heat-treated wood cell walls during moisture desorption process examined by micro-FTIR spectroscopy 127
8.1 Introduction 127
8.2 Materials and methods 129
8.2.1 Materials 129
8.2.2 Experimental instrument for spectral measurement 130
8.2.3 Micro-FTIR spectral data processing 131
8.3 Results and discussion 131
8.3.1 Effective water sorption sites of heat-treated wood 131
8.3.2 Molecular structure change of water 133
8.4 Conclusions 137
References 137
Chapter 9 Molecular association of adsorbed water with cellulose during moisture adsorption process examined by micro-FTIR spectroscopy 143
9.1 Introduction 143
9.2 Materials and methods 146
9.2.1 Materials 146
9.2.2 Micro-FTIR spectroscopy setup 147
9.2.3 Data processing 149
9.3 Results and discussion 149
9.3.1 Micro-FTIR spectra of cellulose nanofiber film 149
9.3.2 Difference spectra of cellulose nanofiber film at various RH levels 150
9.3.3 Different types of water adsorbed by cellulos