Effect of nanoparticle concentration on the crystallinity, vibrational dynamics and morphology of PS/TiO2 nanocomposites: a comprehensive study†

Abstract

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.