Modifying the surface of poly(ethylene terephthalate) nanofibrous materials by alkaline treatment and TiO ₂ nanoparticles

The mutual effects of nano-TiO ₂ and alkaline hydrolysis on the morphology, chemical structure, water absorption, and the dyeing behavior of poly(ethylene terephthalate) nanofibers were investigated via employing scanning electron microscope, Fourier Transform Infra Red Spectroscopy (FTIR) and X-ray diffraction, and measuring water contact angle, 3M repellency, and dye absorption. A direct relation between the alkaline hydrolysis rate and nanofibers hydrophilicity was observed, while the addition of the nano-TiO ₂ led to more hydrophobicity. However, the alkaline hydrolysis had the prominent effect. FTIR spectra illustrated no chemical interaction between the nanoparticles and nanofibers. It was also shown that the dye absorption at dyeing equilibrium and the rate of dyeing were increased by the presence of the nano-TiO ₂ and these effects were intensified by the alkaline hydrolysis. These observations were related to the reduction in the nanofibers diameter and the increase in the surface roughness, as evidenced in the scanning electron microscope, and the increase in the amorphous regions of the nanofibers, as shown by the X-ray diffraction diffractograms.