Dispersion of aminoalkylsilyl ester or amine alkyl-phosphonic acid side wall functionalized carbon nanotubes in silica using sol–gel processing

Aminopropyltriethoxysilane and aminopropyl-phosphonic ester modified carbon nanotubes were prepared by reacting fluorinated carbon nanotubes (F-CNTs) with the 3-aminopropyltriethoxysilane or 3-aminopropyl-phosphonic acid reagents at 120 °C temperature, using pyridine as the base catalyst. These functionalized carbon nanotubes, APTES-CNTs, 1, and APPA-CNTs, 2, were characterized by transmission electron microscopy (TEM), infrared spectroscopy (IR), and thermogravimetric analysis (TGA). The homogeneous dispersion of these functionalized CNTs (0.1%) in silica were also accomplished by sol–gel processing. The TEM confirmed uniform dispersion of the functionalized CNT in silica.