Polymer-Derived Si-Based Ceramics: Recent Developments and Perspectives

Abstract

Polymer derived ceramics (PDCs) are promising candidates for usages as the functionalization of inorganic Si-based materials. Compared with traditional ceramics preparation methods, it is easier to prepare and functionalize ceramics with complex shapes by using the PDCs technique, thereby broadening the application fields of inorganic Si-based ceramics. In this article, we summarized the research progress and the trends of PDCs in recent years, especially most recent three years. Fabrication techniques (traditional preparation, 3D printing, template method, freezing casting techniques, etc.), microstructural tailoring mainly via additive doping, and properties (mechanical, thermal, electrical, as well as dielectric and electromagnetic wave absorption properties) of Si-based PDCs were explicated. Meanwhile, challenges and perspectives for PDCs techniques were proposed as well, with the purpose to enlighten multiple functionalized applications of polymer-derived Si-based ceramics.

Polymer-Derived Lightweight SiBCN Ceramic Nanofibers with High Microwave Absorption Performance

“…It has been accepted that pure SiBCN usually has unsatisfactory EW absorption performance due to its poor dielectric properties and low conductivity. 39 In Figure 7, ε′ and ε″ both increase markedly after increasing the annealing temperature in range of 1000−1600 °C. The ε′ of the resulting SiBCN nanofibers (S1−S4) varies in the ranges of 2.55−2.57, 3.48−3.11, 4.27−3.47, and 4.81−3.78, respectively; however, the ε′ of the nanofibers annealing at 1600 °C (S5) decreases sharply from 12.45 to 7.16 (Figure 7a).…”

“…By means of molecular structure design of polymer precursors, introduction of doping elements, introduction of a high dielectric dispersion phase, and regulation of the cracking process, an optimized multiscale structure and a satisfying chemical composition of the PDCs with high EW absorption property can be achieved. 39 The satisfying dielectric property of the PDCs, of course, is strongly correlated to their unique microstructure, which generally consists of an amorphous matrix acting as an EW insulating phase and crystallized nanocrystals acting as a conductive phase. 40 However, due to the relatively narrow effective absorption bandwidth (EAB) and processing difficulty of some PDCs, their applications in the electromagnetic field are restricted.…”

“…Because polymer-derived ceramics (PDCs), such as SiC, − Si 3 N 4 , , SiOC, , SiCN, − and SiBCN, − have high-temperature semiconducting behavior and superior piezoresistance, they can be naturally utilized as microwave absorbers. By means of molecular structure design of polymer precursors, introduction of doping elements, introduction of a high dielectric dispersion phase, and regulation of the cracking process, an optimized multiscale structure and a satisfying chemical composition of the PDCs with high EW absorption property can be achieved . The satisfying dielectric property of the PDCs, of course, is strongly correlated to their unique microstructure, which generally consists of an amorphous matrix acting as an EW insulating phase and crystallized nanocrystals acting as a conductive phase .…”

Fabrication of (SiC-AlN)/ZrB2 Composite with Nano-Micron Hybrid Microstructure via PCS-Derived Ceramics Route

“…Its products mainly include functional ceramics, abrasives, and high temperature-resistant materials with wide applications [ 1 , 2 ]. Polymer-derived ceramics (PDCs) technology receives increasing attention on the fabrication of SiC ceramics [ 3 , 4 , 5 ]. Different from the traditional ceramic preparation process, the PDCs technology is to crosslink organic polymers, called “ceramic precursors” (for example, polysiloxane, polycarbosilane, polysilazane), before pyrolyzing at high temperatures, releasing CO, CO 2 , H 2 , CH 4 , HCHO, and other small-molecule gases, leaving the ceramic skeleton, finally completing the transformation from polymers to ceramics [ 6 , 7 , 8 ].…”

“…Nevertheless, during the pyrolysis of the ceramic precursors, a large amount of small molecule gas would be released, and the green body would shrink, with the formation of pores and cracks. Defects, such as pores and cracks, could deteriorate the mechanical properties of PDCs, thus limiting the application of PDCs [ 5 ]. For example, Huang et al [ 26 ] used PCS as the ceramic precursor to prepare lightweight SiC by freeze-casting with a porous structure, and its flexural strength was only 3.7–11.3 MPa.…”