High-strength electrospun ceramic ultrafine fibers based on in-situ polymer-derived technology

Improving the mechanical strength of electrospun ceramic ultrafine fibers (UFs) is crucial for both structural and functional applications. Herein, we report a facile strategy of in-situ embedding ZrO2 nanocrystals (NCs) in polycarbosilane-derived silicon carbide (SiC) UFs. The morphology, chemical composition, mechanical properties, and cross-section morphologies of single UFs are characterized to investigate the effects of introducing ZrO2 NCs. Notably, a single ZrO2 NCs/SiC UF with an average ZrO2 NCs size of 4.5 +/- 1.3 nm possesses optimum mechanical performance, it exhibits about 371.3% increase in tensile strength and 6 times improvement in fracture energy when compared with SiC UFs. The uniformly distributed ZrO2 NCs increase the fiber density that reduce the internal defects, which improve the strength of SiC UF. The enhanced fracture energy can be attributed to the efficient fracture energy dissipation mechanism related to the NCs size. This work provides a viable strategy for designing ceramic fibers with enhanced mechanical properties.