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

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.