Cellulose Nanocrystals

Wadood Hamad is Principal Scientist and Research Leader at FPInnovations, as well as Adjunct Professor at the University of British Columbia's Department of Chemistry. FPInnovations is one of the leading Research institutes exploring the industrial manufacturing and applications of cellulose nanocrystals (CNC), and has been a principal driver in the commercial viability of CNC. Dr Hamad's research team is currently focussed on to thematic areas: (i) CNC processing and characterization, and (ii) material synthesis and product development of advanced functional platforms based on CNC. Dr Hamad has been responsible for key developments around CNC synthesis and manufacturing, and holds over 20 patents for CNC applications in polymer nanocomposites, photonics, flexible electronics and optoelectronics, and over 100 peer-reviewed scientific publications appearing in Nature, Nature Communications, Advanced Materials, and elsewhere.

The monograph is an important and timely publication. It presents the state of technical knowledge and understanding about cellulose, the production process to extract cellulose nanocrystals from natural sources of cellulose, the characterization of the nanocrystals and the assessment of their potential application in industrial products and processes. It is a timely publication because cellulose nanocrystals are a key member of the family of cellulosic nanomaterials which are rapidly moving from a focus of scientific research towards commercial production and their introduction into commercial applications. Clive Willis, PhD (from the Foreword) Director General (2003 2005), NanoQuebec ISO Technical Committee 229 on Nanotechnology

• Series Preface xiiiForeword xvProloguex viii1 New Frontiers for Material Development and the Challenge of Nanotechnology 11.1 Perspectives on Nanotechnology 11.2 Societal Ramifications of Nanotechnology 31.3 Bio-inspired Material Development: The Case for Cellulose Nanocrystals 51.4 A Glance at Bio-inspired Hierarchical Materials 91.5 Concluding Thoughts 13Notes 132 Assembly and Structure in Native Cellulosic Fibers 162.1 Physical and Chemical Characteristics of the Cellulose Molecule 162.1.1 The Origin of Cellulose 162.1.2 The Chemistry of Cellulose 182.1.3 The Physics of Cellulose 202.2 Morphology and Structure of Native Cellulosic Fibers 222.3 Physical and Mechanical Properties of Native Cellulosic Fibers 252.3.1 Anisotropy of the Fiber Cell Wall 252.3.2 Mechanical Properties of Cellulosic Fibers 29Notes 323 Hydrolytic Extraction of Cellulose Nanocrystals 333.1 Introduction 333.2 The Liberation of CNCs Using Acid Hydrolysis 353.3 Reaction Kinetics of CNC Extraction 383.3.1 Effects of H2 SO4 Hydrolysis Conditions and Sulfation on CNC Yield of Extraction 383.3.2 H2 SO4 Hydrolysis Reproducibility and Yield Optimization 463.3.3 Commentary on Hydrochloric Acid-Hydrolyzed CNCs 483.3.4 CNC Stability and Post H2 SO4-Hydrolysis Aging 493.4 Processing Considerations for Sustainable and Economical Manufacture of CNCs 503.5 Micro/Nano Cellulosics Other Than CNCs 533.5.1 Microfibrillated Cellulose 533.5.2 Microcrystalline Cellulose 573.5.3 Bacterial Cellulose 60Notes 624 Properties of Cellulose Nanocrystals 654.1 Morphological Characteristics of CNCs 654.2 Structural Organization of CNCs 684.3 Solid-State Characteristics of CNCs 744.3.1 X-Ray Diffractometric Analysis of CNCs 764.3.2 CNCs Phase Structure Based on SS-NMR 814.3.3 Concluding Remarks 874.4 CNCs Chiral Nematic Phase Properties 874.4.1 Ionic Strength Effect on Chiral Phase Separation 884.4.2 Temperature Effect on Chiral Phase Separation 914.4.3 Suspension Concentration Effect on Chiral Phase Separation 924.4.4 Magnetic Field Effect on Chiral Phase Separation 944.4.5 Sonication Effect on Physicochemical Properties 944.5 Shear Rheology of CNC Aqueous Suspensions 954.5.1 Basic Rheological Behavior of CNC Aqueous Suspensions 954.5.2 Sonication Effects on the Microstructure and Rheological Properties of CNCs Suspensions 984.5.3 Concentration Effects on the Microstructure and Rheological Properties of CNC Suspensions 1004.5.4 Temperature Effects on the Microstructure and Rheological Properties of CNC Suspensions 1064.5.5 CNCs Surface Charge Effects on the Microstructure and Rheological Properties of CNC Suspensions 1124.5.6 Ionic Strength Effects on the Microstructure and Rheological Properties of CNC Suspensions 1184.5.7 Aging and Yielding Characteristics of CNC Suspensions 1234.5.8 Concluding Remarks 1284.6 Thermal Stability of CNCs 129Notes 1345 Applications of Cellulose Nanocrystals 1385.1 Prelude 1385.2 The Reinforcing Potential of CNCs in Polymer Nanocomposites 1405.2.1 Basic Concepts in Composites 1405.2.2 Generic Methods for Surface Functionalization 1425.2.3 Why CNCs for Reinforcement? 1475.2.4 Performance of CNCs in Compatible Polymer Systems 1505.2.5 Nanocomposites Prepared by Postpolymerization Compounding of CNCs and Thermoplastic Polymers 1545.2.6 Controlling Nanocomposite Crystallinity and Plasticity via In Situ Polymerization Methodologies in the Presence of CNCs 1655.2.7 CNCs in Thermosetting Polymers: Tailoring Cross-Linking Density and Toughness 1725.2.8 Comments on Modeling the Mechanical Response of CNC-Reinforced Nanocomposites 1775.2.9 Conclusions and Critical Insights 1815.3 CNC-Stabilized Emulsions, Gels, and Hydrogels 1845.3.1 Pickering Emulsions 1845.3.2 High Internal Phase Emulsions 1875.3.3 pH-Responsive Gels and Flocculants 1895.3.4 Hydrogels 1905.4 Controlled Self-Assembly of Functional Cellulosic Materials 1945.4.1 Flexible CNC Films with Tunable Optical Properties 1945.4.2 Mesoporous Photonic Cellulose Films 1975.5 Toward Bio-inspired Photonic and Electronic Materials 2025.5.1 Mesoporous Photonic Materials from Cellulose Nanomaterial Liquid Crystal Templates 2025.5.2 Actuators and Sensors 2175.5.3 Sustainable Electronics Based on CNCs 2255.5.4 Conclusions and Outlook 2325.6 CNCs in Biomedicine and Pharmaceuticals 2335.7 Environmental, Health, and Safety Considerations of CNCs 2355.8 Perspectives and Challenges 238Notes 239Epilogue—The Never-Ending Evolution of Scientific Insights 248Bibliography 252Subject Index 288