Preface xi
1 Modeling (Visco)elasticity of Macromolecular and Biomacromolecular Networks 1
Fanlong Meng
1.1 Permanent Macromolecular Networks 2
1.1.1 Mechanic Properties of a Single Polymer Chain 2
1.1.2 Statistical Models 3
1.1.3 Phenomenological Models 6
1.2 Permanent Biomacromolecular Networks 7
1.2.1 Elastic Models 8
1.2.2 Nonlinear Elasticity, Stability, and Normal Stress 9
1.3 Transient Macromolecular/Biomacromolecular Networks 12
1.3.1 Theoretical Framework 13
1.3.2 Applications 14
1.4 Outlooks 19
References 19
2 Modeling Reactive Hydrogels: Focus on Controlled Degradation 25
Vaibhav Palkar and Olga Kuksenok
2.1 Introduction 25
2.2 Mesoscale Modeling of Reactive Polymer Networks 26
2.2.1 Introducing Dissipative Particle Dynamics Approach for Reactive Polymer Networks 26
2.2.2 Addressing Unphysical Crossing of Polymer Bonds in DPD Along with Reactions 28
2.2.3 Modeling Cross-linking Due to Hydrosilylation Reaction 29
2.2.4 Mesoscale Modeling of Degradation and Erosion 32
2.3 Continuum Modeling of Reactive Hydrogels 39
2.3.1 Modeling Chemo- and Photo-Responsive Reactive Hydrogels 39
2.3.2 Continuum Modeling of Degradation of Polymer Network 40
2.4 Conclusions 42
Acknowledgments 43
References 43
3 Dynamic Bonds in Associating Polymer Networks 53
Jiayao Chen, Xiao Zhao, and Peng-Fei Cao
3.1 Introduction of Dynamic Bonds 53
3.1.1 Dynamic Covalent Bonds 53
3.1.2 Dynamic Noncovalent Bonds 55
3.2 Physical Insight of Dynamic Bonds 57
3.2.1 Segmental and Chain Dynamics 57
3.2.2 Phase-Separated Aggregate Dynamics 60
3.3 Properties and Applications 65
3.3.1 Gas Separation 66
3.3.2 Adhesives and Additives 70
3.3.3 3D Printing 73
3.3.4 Polymer Electrolytes 74
3.4 Conclusion 78
References 78
4 Direct Observation of Polymer Reptation in Entangled Solutions and Junction Fluctuations in Cross-linked Networks 83
Fengxiang Zhou and Lingxiang Jiang
4.1 Introduction 83
4.2 Reptation in Entangled Solutions 84
4.2.1 Direct Confirmation of the Reptation Model 86
4.2.2 Tube Width Fluctuations 88
4.2.3 Dependence of Tube Width on Chain Position 89
4.2.4 Tube Width under Shear 89
4.2.5 Interactions Between Reptating Polymer Chains 90
4.3 Dynamic Fluctuations of Cross-links 92
4.3.1 Dynamics Probed by Neutron Scattering 93
4.3.2 Dynamics Probed by Direct Imaging 94
4.4 Conclusion 98
Acknowledgments 98
Conflict of Interest 98
References 98
5 Recent Progress of Hydrogels in Fabrication of Meniscus Scaffolds 101
Chuanchuan Fan, Ziyang Xu, and Wenguang Liu
5.1 Introduction 101
5.2 Microstructure and Mechanical Properties of Meniscus 102
5.2.1 Meniscus Anatomy, Biochemical Content, and Cells 102
5.2.2 Biomechanical Properties of the Meniscus 104
5.3 Biomaterial Requirements for Constructing Meniscal Scaffolds 105
5.4 Hydrogel-Based Meniscus Scaffolds 106
5.4.1 Providing Matrix for Cell Growth and Biomacromolecules Delivery 106
5.4.1.1 Injectable Hydrogel-Based Meniscus Tissue-Engineering Scaffolds 107
5.4.1.2 High Strength and Biodegradable Hydrogel-Based Meniscus Scaffolds 109
5.4.1.3 3D-Printed Polymer/Hydrogel Composite Tissue-Engineering Scaffolds 109
5.4.2 Providing Load-Bearing Capability 114
5.4.2.1 Polyvinyl Alcohol (PVA) Hydrogel-Based Meniscus Scaffolds 115
5.4.2.2 Poly(N-acryloyl glycinamide) (PNAGA) Hydrogel-Based Meniscus Scaffolds 117
5.4.2.3 Poly(N-acryloylsemicarbazide) (PNASC) Hydrogel-Based Meniscus Scaffold 119
5.4.2.4 Other Systems 120
5.5 Mimicking Microstructure: The Key to Constructing the Next-Generation Meniscus Scaffolds 122
5.6 Conclusion 123
References 124
6 Strong, Tough, and Fast-Recovery Hydrogels 133
BinXueandYiCao
6.1 Current Progress on Strong and Tough Hydrogels 133
6.2 Polymer-Supramolecular Double-Network Hydrogels 136
6.3 Hybrid Networks with Peptide-Metal Complexes 137
6.4 Hydrogels Cross-Linked with Hierarchically Assembled Peptide Structures 139
6.5 Outlook 140
References 141
7 Diffusio-Mechanical Theory of Polymer Network Swelling 149
Zhaoyu Ding, Peihan Lyu, and Xingkun Man
7.1 Introduction 149
7.2 Swelling Model 153
7.2.1 General Theoretical Framework 156
7.2.1.1 Spherical Gel 156
7.2.1.2 Cylindrical Gel 157
7.2.1.3 Disk-Shaped Gel 157
7.2.2 Diffusio-Mechanical Model for Small Deformation 158
7.2.2.1 Spherical Gel 158
7.2.2.2 Cylindrical Gel 162
7.2.2.3 Disk-Shaped Gel 164
7.3 Results 166
7.4 Perspective 169
7.5 Conclusion 171
Acknowledgments 172
References 172
8 Theoretical and Computational Perspective on Hopping Diffusion of Nanoparticles in Cross-linked Polymer Networks 175
Ting Ge
8.1 Introduction 175
8.2 2010s' Theories of Nanoparticle Hopping Diffusion 176
8.2.1 Scaling Theory by Cai, Paniukov, and Rubinstein 176
8.2.1.1 Confinement by Network as Attachment to Virtual Chains 177
8.2.1.2 Hopping Diffusion as Successive Individual Hopping Events 178
8.2.1.3 Beyond Homogeneous, Entanglement-Free, and Dry Cross-linked Networks 180
8.2.2 Microscopic Theory by Dell and Schweizer 182
8.3 Recent Computational and Theoretical Work 183
8.3.1 Evaluating Cai-Paniukov-Rubinstein and Dell-Schweizer Theories by Simulations 183
8.3.2 Exploring New Aspects of Cross-linked Networks - Stiffness and Geometry 185
8.4 Open Questions and Future Research Directions 189
8.4.1 Network Strands with Nonlinear Architectures 189
8.4.2 Sticky and Polymer-Tethered Nanoparticles 191
8.4.3 Nanoparticles with Anisotropic Shape 191
8.4.4 Active Nanoparticles - Nonequilibrium Effects 192
8.5 Concluding Remarks 193
Acknowledgments 193
References 194
9 Molecular Dynamics Simulations of the Network Strand Dynamics and Nanoparticle Diffusion in Elastomers 199
Yulong Chen and Jun Liu
9.1 Introduction 199
9.2 Structures and Dynamics of Model Elastomer Networks 200
9.2.1 Randomly Cross-linked Elastomer Networks 200
9.2.1.1 Network Models and Simulation Methodology 201
9.2.1.2 Network Topology 202
9.2.1.3 Effect of Cross-link Density on Network Dynamics 204
9.2.1.4 Effect of Cross-link Distribution on Network Dynamics 206
9.2.1.5 Effect of Temperature on Network Dynamics 208
9.2.2 End-linked Elastomer Networks 210
9.2.2.1 Network Models and Simulation Methodology 210
9.2.2.2 Network Topology 211
9.2.2.3 Network Dynamics 212
9.3 Diffusion Dynamics of Nanoparticles in Elastomers: Melts and Networks 214
9.3.1 Diffusion of Nanoparticles in Elastomer Melts 215
9.3.1.1 Models and Simulation Methodology 215
9.3.1.2 Size Effect on Nanoparticle Diffusion 216
9.3.1.3 Effect of Surface Grating on Nanoparticle Diffusion 218
9.3.1.4 Nanoparticle Diffusion in Bottlebrush Elastomers 223
9.3.2 Diffusion of Nanoparticles in Elastomer Networks 227
9.3.2.1 Models and Simulation Methodology 227
9.3.2.2 Size Effect on Nanoparticle Diffusion 228
9.3.2.3 Nanoparticle Diffusion in Attractive Networks 232
9.4 Conclusions 236
Acknowledgments 238
References 239
10 Experimental and Theoretical Studies of Transport of Nanoparticles in Mucosal Tissues 245
Falin Tian and Xinghua Shi
10.1 Introduction 245
10.2 Enhancing Diffusivity of Deformable Particles to Overcome Mucus Barriers Via Adjusting Their Rigidity 248
10.2.1 The Preparation of the Hybrid NPs with Various Rigidities 249
10.2.2 The Diffusivity of Hybrid NPs with Different Rigidity in Mucus 250
10.2.3 The Interaction Between NPs with Different Rigidity and Mucus Network 252
10.2.4 The Theoretical Model to Describe the Diffusion Behavior of Deformable Nanoparticles in Adhesion Network 255
10.2.4.1 Shape Distribution of NPs 256
10.2.4.2 Diffusion Model 258
10.2.5 Summary 260
10.3 The Effect of the Shape on the Diffusivity of NPs in Mucus 261
10.3.1 The Diffusion Behaviors of NPs with Various Shapes in Mucus 261
10.3.2 The Diffusion Mechanisms of NPs with Different Shape in Biological Hydrogels 263
10.3.3 Theoretical Model of Diffusion of Rod-Like Nanoparticles in Polymer Networks 265
10.3.3.1 Nonadhesive Diffusion Model 265
10.3.3.2 Adhesive Diffusion Model 268
10.3.4 The Effect of the Surface Polyethylene Glycols (PEGs) Distribution on the Diffusivity of Rod-Like NPs 269
10.3.5 Summary 272
10.4 Conclusion and Outlook 272
References 274
11 Physical Attributes of Nanoparticle Transport in Macromolecular Networks: Flexibility, Topology, and Entropy 281
Xiaobin Dai, Xuanyu Zhang, Lijuan Gao, Yuming Wang, and Li-Tang Yan
11.1 Introduction 281
11.2 Effects of the Chain Flexibility of Strands 282
11.2.1 Dynamical Heterogeneity of a Semiflexible Network 283
11.2.2 Nonmonotonic Feature 284
11.2.3 Validation by MC Simulations and Experimental Data 287
11.3 Effects of Network Topology 288
11.3.1 Analytical Model for Free Energy Landscape 289
11.3.2 Network Topology and Free Energy Landscape 289
11.3.3 Topology-Dictated Scaling Regimes of Free Energy Change 291
11.3.4 Topology-Mediated Dynamical Regimes 294
11.4 Summary and Outlook 295
Acknowledgments 296
References 296
Index 299
