Synthesis of a dendrimeric phenoxy-substituted cyclotetraphosphazene and its non-covalent interactions with multiwalled carbon nanotubes

A dendrimeric phenoxy-substituted cyclotetraphosphazene has been prepared for the non-covalent functionalization of multiwalled carbon nanotubes (MWCNTs). The synthesized cyclotetraphosphazene derivatives (2–4) and dendrimeric cyclotetraphosphazene (5) have been characterized by standard spectroscopic techniques. The functionalization of MWCNTs with compound 5 has been accomplished and the resulting MWCNT-5 hybrid has been characterized by 31P NMR, 1H NMR, Raman spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray (EDX), fluorescence, thermal gravimetric analysis (TGA) and high-resolution transmission electron microscopy (HRTEM) techniques. The results showed that the dendrimeric compound 5 has been attached to the MWCNTs via non-covalent “π–π” interactions between the phenoxy groups on the dendrimeric compound 5 and the extended π system of the MWCNTs. The MWCNT-5 hybrid exhibited significant dispersion stability in common organic solvents.

Graphical abstractIn the present study, we describe the synthesis and characterisation of a soluble multi-walled carbon nanotube/dendrimeric phenoxy-substituted cyclotetraphosphazene nanocomposite via non-covalent “π–π” interactions. The thermal, morphological and spectroscopic properties of the hybrid material are investigated. The hybrid material shows both high thermal stability and excellent fluorescence quenching efficiency. Also the hybrid shows significant dispersion stability in common organic solvents.Figure optionsDownload full-size imageDownload as PowerPoint slide