Single-handed helical SiC fiber preparation using 1,4-phenylene-bridged polybissilsesquioxane

•Single-handed helical SiC fibers were prepared.•The helical SiC fibers consisted of nanoparticles.•The helical SiC fibers were optically active.

Single-handed helical mesoporous 1,4-phenylene-bridged polybissilsesquioxane fibers were synthesized using a previously reported supramolecular templating approach by increasing the concentration of NaOH. They exhibit optical activity and the size of the mesopores is approximately 2.5 nm. Single-handed helical SiC fibers, which consisted of β-SiC nanoparticles, were prepared by carbothermal reduction of the 1,4-phenylene-bridged polybissilsesquioxane fibers. The handedness of the SiC fibers was the same as that of the mesoporous 1,4-phenylene-bridged polybissilsesquioxane fibers. The left- and right-handed helical SiC fibers showed opposite optical activities. Signals were identified in the diffuse reflectance circular dichroism spectra. Since the β-SiC phase belongs to the non-chiral F¯43m space group, we suggest that the optical activity originates from chiral defects on the SiC nanoparticle surfaces.

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