This book brings together detailed information on gels, hydrogels, and aerogels derived from natural polymers, covering materials, processing, fabrication techniques, structure-property relationships, and novel applications. Also, It has separate chapters focusing on physical processes, chemical processes, green processes, and processing for aerogels.The final chapters of this book focus on the preparation of natural polymer-based gels, hydrogels, and aerogels for many state-of-the-art applications, including biomedical, absorbent, energy saving, filtration, and sensing areas.