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 Si[O.sub.2] nanotubes. The obtained nanocomposite is a candidate material for gas sensing applications. Key words: silica nanotubes, polymer, high pressure, transmission electron microscopy, Raman spectroscopy. Du phenylacetylene a ete insere puis polymerise dans des nanotubes de silice de diametre 5 nm dans de conditions de haute pression 0,5 GPa et haute temperature 437 K. Le nanocomposite obtenu a ete caracterise par spectroscopies infrarouge et Raman et par microscopies electronique a balayage et en transmission. Les donnees de spectroscopie vibrationnelle ont confirme la formation de polyphenylacetylene n-conjugue ainsi que l'absence de cristallisation des nanotubes amorphes. La microscopie electronique en transmission a balayage, couplee a la spectroscopie des rayons X en dispersion d'energie a confirme Tinsertion du polymere a l'interieur des canaux des nanotubes. La diffraction electronique a confirme la nature amorphe du polymere et des nanotubes de Si[O.sub.2] hote. Le nanocomposite est un candidat comme materiau pour les capteurs de gaz. Mots-cles: nanotubes de silice, polymere, haute pression, microscopie electronique en transmission, spectroscopie Raman.
Introduction Polyphenyacetylene (1-10)has attracted particular attention over the past decades as a p-conjugated system, which can be used as a conducting polymer. Conducting polymers present a considerable interest for applications [...]