Structural Design of Electrospun Ceramic Nanofibers

Design of ceramic nanofibers with complex surface, inner structure and specific chemical and physical properties is required for materials with improved performance in diverse applications. Fiber architecture offers a built-in directionality within the material as well as reduction of mass transport limitation and accessibility to a large functional surface. Porous or hollow fiber structures provide additional inner surface, opening opportunities for impregnation, and creation new interfaces within the porous body. Electrospinning is an effective method to produce continuous nanofibers of diverse materials. Obtaining the desired morphology in such fibers is the main challenge addressed in this presentation. Typically, electrospun nanofibers are synthesized from solutions that contain solvents and polymers for rheological reasons. The desired ceramic phase is obtained after drying and polymer removal by thermal treatment. During this stage, fibers shrinkage, deformation, and phase and morphology changes occur. The presentation will focus on creation of nanofibers with diverse surface and inner structures from variety of materials. Formation of lamellar, hollow and belt architectures for specific applications will be discussed. Models leading to these morphologies are suggested, showing the interplay between process conditions and the nanofibers' complex surface and inner structure. The relation between synthesis conditions, morphology and performance will be discussed in diverse cases such as catalytic, thermoelectric and electrochemical systems.