木材细胞壁水分吸附

木材水分是影响木材物理力学性能及其储存和加工使用的核心要素，木材水分关系一直是木材科学的重点研究课题。早在1888年，Science杂志就刊登木材水分关系的学术论文，1988年Springer出版木材水分关系的学术专著《木材与水分》。随后，木材水分关系研究进入发展期。早期研究侧重于木材水分含量即含水率的测定以及含水率模型的建立及修正。随着以高速计算机为主导、具有空间分辨功能的优选分析仪器的应用，木材中水分分布以及存在状态研究蓬勃兴起。本书紧紧围绕木材水分关系研究的关键核心问题-木材中水分分布以及存在状态，重点介绍显微红外光谱和显微拉曼光谱用于木材中水分分布以及存在状态研究获得的近期新进展，在细胞水平、分子水平上构建木材水分吸附理论体系，为木材化学改性、高效干燥以及新型高值木质材料制备工艺优化和技术开发提供科学依据和理论指导。

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 cellulose nanofiber film 151
9.4 Conclusions 155
References 155
Chapter 10 Spatial distribution of adsorbed water in cellulose film studied using micro-FTIR spectroscopy 161
10.1 Introduction 161
10.2 Materials and methods 163
10.2.1 Materials 163
10.2.2 Micro-FTIR experimental setup 163
10.3 Results and discussion 166
10.3.1 Qualitatively analyzing water adsorption in cellulose nanofiber film 166
10.3.2 Spatial distribution of cellulose in the cellulose nanofiber film 167
10.3.3 Spatial distribution of adsorbed water in the cellulose nanofiber film 168
10.4 Conclusions 171
References 171
Chapter 11 Water vapor sorption properties of sulfuric acid treated and TEMPO oxidized cellulose nanofiber films 177
11.1 Introduction 177
11.2 Material and methods 181
11.2.1 Materials 181
11.2.2 DVS apparatus 182
11.2.3 X-ray diffraction (XRD) 182
11.2.4 Modulus measurement 183
11.3 Results and discussion 183
11.3.1 Water vapor sorption behavior 183
11.3.2 Sorption hysteresis 185
11.3.3 Sorption kinetics 187
11.3.4 The applicability of the Kelvin-Voigt model 189
11.4 Conclusions 191
References 191
Chapter 12 Water vapor sorption properties of cellulose nanocrystals and nanofibers using dynamic vapor sorption apparatus 197
12.1 Introduction 197
12.2 Material and methods 200
12.2.1 Materials 200
12.2.2 DVS setup 200
12.3 Results and discussion 201
12.3.1 Water vapor sorption behavior 201
12.3.2 Sorption hysteresis 204
12.3.3 Sorption kinetics 207
12.3.4 The applicability of Kelvin-Voigt model 212
12.4 Conclusions 218
References 218