This behavior reproduces when other TAA are used, being observed
that the interlayer distance is a function of the alkyl chain length
when the reaction time is constant (see Fig. 4b).
Typical FT-IR spectrum of a TAA/TiP nanotubular compound is
reported in Fig. 5. Absorption band at 450–700 cm−1 was assigned
to Ti O stretching, bands in the region 900–1200 cm−1 assigned
to the P O stretching, and 575 cm−1 to the P O bending modes
in the phosphate groups, while the band at 1220–1250 cm−1 is
associated with the out-of-plane deformation of the P O H groups
and symmetric C N bond stretching. Deformation vibration N H is
observed at 1600 cm−1. The bands at 1500 cm−1 assigned to CH2
and CH3 scissor vibrating and in the region 2800–3000 cm−1 are
corresponding to the asymmetric and symmetric stretching vibrations.
Broad band at 3400–3700 cm−1 are assigned to O H bonds,
and N H bonds consequence of the alkylammonium cation formation
[12,13].