Materials science encompasses four classes of materials, the study of each of which may be considered a separate field: metals, ceramics, polymers and composites. This volume gathers important research from around the globe in this dynamic field including research on the electroluminescent and photo luminescent properties of semiconductor-based materials with different structures; advantages of reactive extrusion for the synthesis of polyurethanes for biomedical applications; pyridine-type defects in graphene; amorphous silicon carbide thin film formation at room temperature; hydrogen gas sensor based on material with yttrium nanoparticles; influence of supercritical carbon dioxide for pharmaceutical processing; polymerizable dyes containing heterocyclic derivatives of polyureas and polyurethanes; the b-nucleation in polypropylene and its effect on the mechano-physical and thermal properties; and the effect of hydrogen on boron doped amorphous silicon prepared by magnetron sputtering.