Said El-Sheikh

Carbide and nitride based boron ceramics have attract a significant attention, especially in the field of structural and refractory ceramics. They promoted by a high thermal stability, additionally; they hold the second and third hardest materials after diamond. These excellent properties evaluate boron carbide/nitride ceramics for most important applications: they used as cutting tools and refractory materials. Boron carbide, nitride and their composites produced during carbothermic reduction reaction (CRR), using lactose and boric acid as carbon and boron sources, respectively. The studied parameters were the carbon/boron molar ratio, the reaction temperature and reaction time. The produced materials characterized from different point of views regarding chemical, physical, thermal and electrical properties. Finally, the materials tested for electrochemical properties and thermal stability for advanced application.

Innovative cement-based composites are recently strongly emerging technology. Nanotechnology is one of the potential alternatives to improve cement characteristics and to decrease the amount of cement used in various applications, which consequently reduces the energy required for cement production and carbon dioxide emission caused by cement industry. In this book, some approaches for improvement of cement were conducted. Incorporation of waste materials or small amounts of prepared inexpensive nanomaterials was considered in this study as a viable strategy for cement reinforcement. Iron slag as waste material and titanate nanofibers were introduced to cement paste separately or as a mixture to evaluate the mechanical, morphological and chemical properties of the solidified cement blend. The produced composite prepared from Portland cement, iron slag and small amounts of titanate nanofibers has subjected towards several mechanical, physical and chemical testing after drastic events; based on the elaborated results, the new composite formulation can be suggested as matrix both for safe immobilization of hazardous wastes and as a valuable material to be used in building industry.