Different from traditional fibers, heteromorphic fibers with non-circular cross-section can be used to build multi-level nanostructures, prepare light and high-strength composite materials, and develop materials with special absorption and electromagnetic absorption functions. Silicon boron oxygen carbon (siboc) ceramic fiber has excellent physical, mechanical and high temperature properties, such as low density, high strength, high temperature resistance and oxidation resistance. It has an important application prospect in aerospace and other high-tech fields. Nanostructured SiBOC ceramic continuous fibers, including flower shaped, T shaped and Y shaped fibers, were prepared by sol gel method.

Using tetraethyl orthosilicate (TEOS) and two methyl two ethoxy silane (DMDES) as sol gel system, water as solution, nitric acid as catalyst, boric acid trimethyl ester (TMB) as boron source, various kinds of polydiborosiloxane (PBSO) gel fibers were obtained by various spinning methods, and SiBOC fibers were formed by pyrolysis at 1000 degrees.

The diameter of siboc fiber is 20-80 μ m, and it has flower, t, y and triangle sections. The structure of siboc fiber is compact. The fiber morphology can be controlled by controlling spinning speed, solution viscosity and drawing method. Compared with PBSO gel fibers, IR analysis of B-O-Si fibers indicates that the SiBOC fiber is a amorphous network structure composed of B atoms and SiOC.