Synthesis and electromagnetic wave absorbing properties of a polymer-derived SiBNC ceramic aerogel

In this work, SiBNC ceramic aerogels were prepared by the hydrosilylation reaction between precursor polyborosilazane and a cross-linking agent divinylbenzene in a highly diluted solvent, with the presence of Karstedt catalyst. The obtained SiBNC ceramic aerogels possess the characteristics of light weight, high porosity, and relatively wide pore size distribution (3–140 nm). The electromagnetic wave (EMW) absorption of the SiBNC aerogels was studied by a vector network analyzer. When the solvent fraction was 90%, the sample thickness was 3.0 mm, and the SiBNC aerogel had good absorption properties with a reflection loss of 25.05dB@16.07 GHz. These SiBNC ceramic aerogels also showed excellent temperature resistance and a unique three-dimensional network structure. They are thus expected to find application in the high-temperature absorption field.