Poly(vinyl alcohol)/CNT composites: An effect of cross-linking with glutaraldehyde

We propose a new method of preparation of the cross-linked composites of poly(vinyl alcohol) (PVA) with carbon nanotubes (CNTs), in which the formation of new covalent bonds does not involve the nanotube entities, but instead PVA macromolecules only. The method consists in the addition of glutaraldehyde to PVA/CNT dispersions in order to cross-link PVA chains via an acetalization reaction. The composites prepared were studied by scanning electron microscopy, atomic force microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy and thermogravimetric analysis. The addition of 0.5 and 1% of single-walled and multi-walled CNTs (SWNTs and MWNTs, respectively) considerably changes the morphology and thermal stability characteristics of the glutaraldehyde cross-linked PVA. The use of SWNTs is believed to be more advantageous due to their better dispersion within the PVA phase as compared to MWNTs.