Effect of Nanoparticle Concentration on the Crystallinity, Vibrational Dynamics, and Morphology of PS/TiO2 Nanocomposites

Abstract

This study investigates the impact of rutile-phase TiO₂ nanoparticles on the structural, morphological, and vibrational properties of polystyrene (PS)-based nanocomposites at TiO₂ concentrations of 3, 5, and 10%. The nanocomposites were prepared by mixing solutions and hot pressing. XRD revealed increased crystallinity at higher TiO₂ content, with crystallite sizes ranging from 5.77 to 8.05 nm. TEM showed well-dispersed nanoparticles (30–50 nm) in the 3% TiO₂ samples, with agglomeration increasing at 5% TiO₂. AFM indicated a rougher surface for the 3% TiO₂ (90–160 nm) and smoother, more homogeneous surfaces for the 10% TiO₂ (50–130 nm), which can be attributed to improved dispersion. Raman spectroscopy identified TiO₂ peaks (447, 618, and 905 cm^–1), which intensified with increasing TiO₂ content, while shifts in the PS peaks suggested interactions between the matrix and nanoparticles. These results emphasize the critical role of dispersion and TiO₂ loading in determining the properties of the PS nanocomposite.