HUA Hongzhan, LIANG Feng, TIAN Yu, ZHANG Haijun

(State Key Laboratory of Advanced Refractories, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China)

Extended abstract:

[Significance] Fibrous cellular ceramics are a class of porous ceramic materials characterized by three-dimensional interconnected network constructed from interwoven ceramic fibers and hierarchical pore structure. In comparison with conventional dense ceramics, fibrous cellular ceramics exhibit a combination of low bulk density, high specific surface area, favorable permeability, high thermal shock resistance and stable performance at elevated temperatures. These structural and functional characteristics endow fibrous cellular ceramics with significant potential for applications in thermal insulation, filtration and acoustic absorption, particularly in harsh service environments. In aerospace engineering, fibrous cellular ceramics are widely employed as lightweight thermal protection materials to shield critical components from severe thermal conditions encountered during hypersonic flight or atmospheric re-entry. In high-temperature industrial furnaces, they are used as insulating linings to reduce heat loss and improve energy utilization efficiency. Moreover, the increasing demand for energy conservation, emission reduction and lightweight structural materials has further stimulated interest in fibrous cellular ceramics, across energy, automotive and environmental engineering fields. With the rapid development of advanced manufacturing technologies, fibrous cellular ceramics with controllable microstructures and multifunctional performance are increasingly required. Therefore, a systematic review of their preparation methods and application progress is of considerable scientific significance and practical value, as it provides a comprehensive understanding of current research status and offers guidance for future material design and industrial application.

[Progress] In recent years, notable progress has been achieved in the fabrication and application of fibrous cellular ceramics. Various preparation techniques have been developed and optimized to tailor fiber morphology, pore structure and macroscopic architecture. Among these methods, solution blow spinning (SBS) has attracted increasing attention as an efficient technique for producing continuous ceramic fibers with diameters ranging from the nanometer to micrometer scale. This method features relatively high production efficiency and low equipment requirements, which makes it suitable for large-scale fabrication of ceramic fiber mats. However, the formation of uniform fibrous networks via SBS still requires careful control of processing parameters, such as solution viscosity, gas pressure and spinning distance, to mitigate issues related to fiber agglomeration. In addition to SBS, several conventional forming techniques are commonly employed in the preparation of fibrous cellular ceramics. Dry pressing is a cost-effective and straightforward method, which is suitable for fabricating components with simple geometries, although it generally suffers from limited structural flexibility and non-uniform pore distribution. Gel casting enables the preparation of complex-shaped components with relatively uniform microstructures. However, its application is often restricted by long processing cycles and the involvement of organic additives. Other pore-forming approaches, such as vacuum filtration and freeze-drying, play important roles in constructing three-dimensional fiber networks and regulating pore characteristics. Vacuum filtration allows the rapid assembly of fibrous frameworks, whereas freeze-drying facilitates the formation of hierarchical pore structures through solvent sublimation. Nevertheless, these techniques may face challenges related to energy consumption, fiber orientation effects and scalability. With respect to applications, fibrous cellular ceramics have expanded beyond their traditional roles in thermal insulation and sound absorption. Recent studies have reported their application in oil–water separation, where surface modification strategies are employed to impart superhydrophilic and underwater superoleophobic properties, enabling efficient separation of oil–water mixtures. In the field of high-temperature flue gas purification, fibrous cellular ceramics demonstrate high resistance to thermal and chemical corrosion. When combined with catalytic active components, they can effectively capture fine particulate matter and reduce emissions of harmful gases, such as sulfur oxides and nitrogen oxides. Furthermore, owing to their interconnected pore structures, fibrous cellular ceramics exhibit favorable sound absorption performance, particularly in the medium- and high-frequency ranges, due to the enhanced viscous and thermal energy dissipation capabilities.

[Conclusions and prospects] Recent research progress in fibrous cellular ceramics is summarized, with emphasis on their preparation strategies and application. Fabrication methods, including solution blow spinning, dry pressing, gel casting, vacuum filtration and freeze-drying, all present distinct advantages and limitations, in terms of structural control, processing cost and scalability. Correspondingly, fibrous cellular ceramics have demonstrated promising performance in thermal insulation, acoustic absorption, oil-water separation and high-temperature gas purification, highlighting their versatility and potential in advanced engineering applications.Despite these advances, the large-scale application of fibrous cellular ceramics is constrained by several factors, such as relatively high production costs, insufficient understanding of structure–property relationships and limited capability for precise structural customization. Future research should be focused on the development of environmentally friendly and energy-efficient preparation processes, as well as the establishment of quantitative relationships between fiber characteristics, pore structure parameters and functional properties. In addition, the integration of advanced manufacturing technologies, such as three-dimensional printing, may enable the fabrication of fibrous cellular ceramics with tailored architectures and improved performance. The exploration of high-entropy ceramic fibers is also expected to enhance the thermal stability, corrosion resistance and mechanical reliability of fibrous cellular ceramics under extreme service conditions. Overall, continued research efforts in these directions may promote the further development and practical application of fibrous cellular ceramics in advanced manufacturing and high-temperature engineering fields.

Key words: ceramic fibers; cellular ceramics; fabrication techniques; application status