Bioinspired Water Harvesting, Purification, And Oil-water Separation (springer Series In Materials Science (299))

This book presents an overview of arid desert conditions and natural mechanisms for water harvesting from fog and condensation, providing data on various bioinspired surfaces for water collection. It discusses consumer to military and emergency applications. It presents various designs for water harvesting towers and projections for water collection, and describes innovative approaches to bioinspired water desalination, water purification and oil-water separation. Fresh water sustains human life and is vital for health. However, water scarcity affects more than 40% of the global population and is projected to rise, especially in some of the world’s most impoverished countries. Additionally, water contamination is one of the most critical environmental and natural resource concerns of the 21st century. This book addresses these topics with a presentation of the development of sustainable and environmentally friendly bioinspired surfaces for water harvesting from fog and condensation, as well as bioinspired oil-water separation techniques for removing oil contaminants from oil-water mixtures and oil-water emulsions. Intended for novices as well as experts in the field, the book offers actionable insight for practitioners, solution seekers, and the generally curious alike. It serves as an excellent accompanying text for one-semester courses in biomimetics, water supply and management, or environmental engineering. Preface Contents About the Author 1 Introduction: Water Supply and Management 1.1 Water Supply 1.2 Water Consumption 1.3 Water Contamination 1.4 Human Impact from Lack of Safe Water Supply 1.5 Lessons from Nature to Supplement Water Supply and Remove Contamination 1.6 Organization of the Book References 2 Overview of Arid Desert Conditions, Water Sources, and Desert Plants and Animals 2.1 Water Sources 2.1.1 Fog and Mist 2.1.2 Condensation of Water Vapor 2.2 Desert Plants and Water Harvesting Mechanisms 2.2.1 Wildflowers 2.2.2 Cacti and Other Succulents 2.2.3 Trees and Shrubs 2.2.4 Grasses, Mosses and Lichens 2.2.5 Summary of Water Harvesting Mechanisms 2.3 Desert Animals and Water Harvesting Mechanisms 2.3.1 Mammals 2.3.2 Birds 2.3.3 Reptiles 2.3.3.1 Snakes 2.3.3.2 Lizards 2.3.3.3 Tortoises 2.3.4 Fish 2.3.5 Amphibians 2.3.6 Invertebrates 2.3.6.1 Beetles 2.3.6.2 Flat Bugs 2.3.6.3 Crustaceans 2.3.7 Summary of Water Harvesting Mechanisms References 3 Selected Water Harvesting Mechanisms—Lessons from Living Nature 3.1 Cactus 3.2 Grass 3.3 Desert Moss 3.4 Bushes 3.5 Namib Desert Beetles 3.6 Lizards 3.7 Rattlesnakes 3.8 Spider Webs 3.9 Summary Appendix 3.A: Laplace Pressure Gradient on a Conical Surface Appendix 3.B: Definition of Various Wetting States References 4 Bioinspired Flat and Conical Surfaces for Water Harvesting 4.1 Experimental Details 4.1.1 Fabrication of Water Collector Surfaces for Fog 4.1.1.1 Flat Surfaces with Homogeneous and Heterogeneous Wettability 4.1.1.2 Conical Surfaces With and Without Grooves and Homogeneous and Heterogeneous Wettability 4.1.2 Fabrication of Water Collector Surfaces for Condensation 4.1.2.1 Single Cone 4.1.2.2 Array 4.1.3 Experimental Apparatuses for Water Collection 4.1.3.1 Single Droplet Experiments 4.1.3.2 Water Collection from Fog 4.1.3.3 Water Collection from Condensation 4.1.3.4 Water Collection Measurements 4.2 Results and Discussion—Fog Water Collection Studies 4.2.1 Flat Surfaces with Various Wettability and Beetle-Inspired Surfaces at 45° and 0° Inclination Angles 4.2.2 Cylinder Versus Cone at 0° Inclination Angle 4.2.3 Cones at 45° Inclination Angle and Comparison with Flat Surfaces 4.2.4 Single Droplet Experiments on Cones 4.2.5 Cones—Effect of Geometry, Inclination, Grooves and Heterogeneous Wettability 4.2.5.1 Two Tip Angles with Same Surface Area 4.2.5.2 Two Tip Angles with Same Length 4.2.5.3 Inclination Angle 4.2.5.4 Velocity of Droplets 4.2.5.5 Grooves 4.2.5.6 Heterogeneous Wettability 4.2.5.7 Conical Array 4.2.5.8 Summary 4.2.6 Nonlinear Cones 4.2.7 Projection for Water Collection Rates 4.3 Results and Discussion—Water Condensation Studies 4.3.1 Cylinder Versus Cone 4.3.2 Two Tip Angles with Same Surface Area 4.3.3 Two Tip Angles with Same Length 4.3.4 Inclination Angle 4.3.5 Array 4.3.6 Trends in Water Collection in Condensation Versus Fog 4.4 Design Guidelines for Water Harvesting Systems References 5 Bioinspired Triangular Patterns on Flat Surfaces for Water Harvesting 5.1 Experimental Details 5.1.1 Fabrication of Water Collection Surfaces 5.1.1.1 Single Triangular Patterns and Triangular Array 5.1.1.2 Rectangular and Triangular Patterns with Multistep Wettability Gradient 5.1.1.3 Nested Triangular Patterns 5.1.2 Experimental Apparatuses for Water Collection 5.1.2.1 Water Collection from Condensation 5.1.2.2 Water Collection from Fog 5.1.2.3 Water Collection from Fog and Condensation 5.1.2.4 Water Collection Measurements 5.2 Results and Discussion—Water Condensation Studies 5.2.1 Rectangular Versus Triangular Pattern and Various Wettabilities 5.2.2 Single Droplet Experiments on Hydrophilic Triangular Patterns 5.2.3 Hydrophilic Triangular Patterns—Effect of Geometry and Relative Humidity 5.2.3.1 Included Angles 5.2.3.2 Relative Humidity 5.2.4 Array of Hydrophilic Triangular Patterns 5.2.5 Summary 5.3 Results and Discussion—Fog Water Collection Studies 5.3.1 Included Angles 5.3.2 Array of Triangular Patterns 5.3.3 Summary 5.4 Results and Discussion—Fog Water Collection and Condensation Studies 5.4.1 Flat Hydrophilic Surfaces Under Different Conditions 5.4.2 Triangular Patterns Under Different Conditions 5.4.3 Array of Triangular Patterns Under Fog and Condensation 5.4.4 Summary 5.5 Results and Discussion—Water Condensation Studies Using Surfaces with Multistep Wettability Gradient 5.5.1 Single Droplet Experiments on Flat Surfaces 5.5.2 Rectangular Sample Patterns 5.5.3 Triangular Patterns 5.5.4 Summary 5.6 Results and Discussion—Water Condensation Studies Using Nested Triangular 5.6.1 Single Droplet Experiment 5.6.2 Water Condensation and Transport on Patterns 5.6.3 Summary 5.7 Design Guidelines for Water Harvesting Systems References 6 Commercial Applications, Projections of Water Collection, and Design of Water Harvesting Towers 6.1 Commercial Applications 6.2 Projection of Water Collection Rates in Water Harvesting 6.3 Design of Water Harvesting Towers 6.4 Operational and Maintenance Cost 6.5 Scaleup and Commercialization Issues References 7 Bioinspired Water Desalination and Water Purification Approaches Using Membranes 7.1 Multi-cellular Structures 7.2 Aquaporins 7.2.1 Pore-Forming Molecules 7.2.2 Carbon Nanotubes 7.2.3 Self-assembled Block Copolymers 7.3 Dual pH- and Ammonia-Vapor-Responsive Electrospun Nanofibrous Polymer Membranes with Superliquiphilic/Phobic Properties 7.4 Summary References 8 Selected Oil-Water Separation Techniques—Lessons from Living Nature 8.1 Lotus Leaf and Shark Skin for Superliquiphobicity/philicy 8.2 Fabrication Approaches for Superliquiphobic/philic Porous Surfaces for Oil-Water Separation References 9 Bioinspired Oil-Water Separation and Water Purification Approaches Using Superliquiphobic/philic Porous Surfaces and External Stimuli 9.1 Coated Stainless Steel Mesh for Separation of Immiscible Oil-Water Mixtures 9.1.1 Fabrication Technique 9.1.2 Characterization of Coated Glass Surfaces 9.1.2.1 Surface Morphology 9.1.2.2 Wettability 9.1.2.3 Wear Resistance 9.1.3 Characterization of Coated Stainless Steel Mesh Surfaces for Oil-Water Separation 9.1.4 Applications to Oil Spill Cleanup and Water Purification 9.1.5 Summary 9.2 Coated Cotton Fabric for Separation of Immiscible Oil-Water Mixtures 9.2.1 Fabrication and Characterization Techniques 9.2.2 Surface Morphology and Wettability 9.2.3 Physical and Chemical Durability 9.2.4 Self-cleaning Properties 9.2.5 Separation of Immiscible Oil-Water Mixtures 9.2.6 Summary 9.3 Coated Cotton for Separation of Oil-Water Emulsions 9.3.1 Fabrication and Characterization Techniques 9.3.1.1 Fabrication Technique 9.3.1.2 Preparation of Emulsions 9.3.1.3 Wettability 9.3.1.4 Separation Method of Immiscible Mixtures and Emulsions 9.3.2 Surface Morphology and Wettability 9.3.3 Separation of Oil-Water Mixtures 9.3.3.1 Immiscible Oil-Water Mixtures 9.3.3.2 Oil-in-Water Emulsions 9.3.4 Summary 9.4 TiO2-Based Material Using UV Stimulus for Water Purification 9.4.1 Fabrication Technique of a Switchable Superliquiphobic/philic Coating 9.4.2 Photocatalytic Degradation of Contaminants for Water Purification 9.4.3 Water Purification Studies 9.4.4 Summary 9.5 Closure Appendix 9.A: Introduction to Various Oil-Water Separation Techniques Commercially Used for Oil Spill Cleanup 9.A.1 Dispersants 9.A.2 Controlled Burning 9.A.3 Sorbents 9.A.4 Skimmers 9.A.5 Booms References 10 Closure References Index