Synthesis of a polyphenylacetylene/silica nanotube composite under high-temperature, high-pressure conditions

Phenylacetylene was inserted and polymerized in 5 nm diameter silica nanotubes under high pressure - high temperature conditions of 0.5 GPa and 437 K in an inert gas. The resulting nanocomposite was characterized by infrared and Raman spectroscopy and scanning and transmission electron microscopy. The vibrational spectroscopic data confirmed the formation of pi-conjugated polyphenylacetylene and the absence of crystallization of the amorphous nanotubes. Scanning transmission electron microscopy coupled with energy dispersive X-ray spectroscopy, STEM-EDX, measurements confirmed the insertion of the polymer in the channels of the nanotubes and electron diffraction confirmed the amorphous nature of both the polymer and the host SiO2 nanotubes. The obtained nanocomposite is a candidate material for gas sensing applications.