Phase separation in polymer blends has achieved a tremendous techno-commercial importance. Most of the applications of polymer blends, such as tissue engineering, membrane technology, electromagnetic shielding, energy harvesting, structural materials, packaging, smart multiphase polymer coatings, depend on the morphologies developed during processing. This book outlines the fundamental aspects of polymer blend thermodynamics, the state-of-the-art processing techniques for specific polymer blend systems currently in use, and the design and fabrication of multiphasic polymeric materials, which will present a multiplicity of opportunities in the water remediation, packaging, and electronic industries, to mention a few. It emphasizes recent research developments, processing techniques, characterization methods, factors influencing phase separation temperature in phase-separated, including partially miscible, polymer blends, and key research challenges in the development of phase-separated polymers materials. With unique and systematic coverage of the journey from fundamentals to applications in polymer blends, this book is ideal for polymer scientists and engineers, material scientists, researchers, engineers, and under- and post-graduate students who are interested in this exciting field of research. It will help industrial researchers and R&D managers bring advanced phase-separated polymer materials/products to the market.