Effect of nanoparticle concentration on the crystallinity, vibrational dynamics and morphology of PS/TiO₂...

This study investigates the influence of rutile-phase TiO₂ nanoparticles on the structural, morphological, and vibrational properties of polystyrene (PS)-based nanocomposites at 3%, 5%, and 10%TiO₂ concentrations. Nanocomposites were fabricated via solution mixing and hot pressing. TEM revealed well-dispersed nanoparticles (30-50 nm) in 3% TiO₂ samples, with agglomeration increasing at 5%TiO₂. AFM showed a rougher surface for 3% TiO₂ (90-160 nm) and smoother, more uniform surfaces for 10%TiO₂ (50-130 nm), attributed to improved dispersion. XRD indicated enhanced crystallinity with higher TiO₂ content, with crystallite sizes between 5.77 nm and 8.05 nm. Williamson-Hall and Halder-Wagner analyses highlighted strain effects at lower concentrations. Raman spectroscopy identified TiO₂ peaks (447 cm^-1, 618 cm^-1, 905 cm^-1) intensifying with TiO₂ content, while PS peak shifts suggested matrix-nanoparticle interactions. These results underscore the critical role of TiO₂ dispersion and loading in determining PS nanocomposite properties.