Title:Investigation of the Effects of Different Phases of TiO2 Nanoparticles on PVA Membranes
Volume: 14
Issue: 3
Author(s): Akanksha Mehto*, Jyotsna Chauhan and Varsha R. Mehto
Affiliation:
- Department of Nanotechnology, Rajiv Gandhi Technical University, Bhopal, 462033, India
Keywords:
Membrane, polymer nanocomposites, CTC, TEM, AFM, UV-visible.
Abstract:
Introduction: PVA/TiO2 nanocomposite membranes are prepared by solution
casting technique where different phases of TiO2 nanoparticles like brookite, brookiterutile
and rutile are dispersed in PVA matrix. Sol-gel method was employed to prepare
TiO2 nanoparticles, while different phases of TiO2 have been obtained by controlling the
calcination temperature.
Methods: PVA/TiO2 nanocomposite membranes were characterized by XRD, FTIR,
AFM, TEM, UV-visible and PL techniques. XRD results confirmed the presence of different
phases of TiO2, exhibiting 3.3 nm, 8.4 nm, and 35.7 nm mean crystalline size. The
XRD studies also confirmed that TiO2 nanoparticles became properly dispersed to the
PVA matrix, leading to increased PVA crystallinity after doping of different phases of
TiO2 nanoparticles. UV-visible analysis revealed an increase in absorption intensity and
peak position shifts slightly towards longer wavelengths, which indicates that nanofillers
tuned the band gap of PVA. The doping of the TiO2 (brookite) phase in the PVA matrix
results in a decreased in PL intensity.
Results: This suggests that the PVA/TiO2 (brookite) membrane exhibits a greater degree
of photocatalytic activity in comparison to the other two composites. According to the
FTIR investigation, the hydroxyl (OH) groups present in PVA interact with the dopants
Ti+ ions via intra- and intermolecular hydrogen bonds to produce charge transfer complexes
(CTC). The AFM study shows surface roughness details for PVA and PVA/TiO2
composite membranes. The average grain size of TiO2 nanoparticles calculated from
TEM images is in good agreement with the grain size calculated by XRD.
Conclusion: By adjusting the phase of TiO2 nanoparticles into PVA matrix, composites
can be developed that are optimized for a variety of applications such as water purification,
UV protection, self-cleaning surfaces, lithium-ion batteries, and optoelectronic devices.