Akademik Veri Yönetim Sistemi
Optical Materials, cilt.176, 2026 (SCI-Expanded, Scopus)
This study aims to systematically elucidate how graphene-modified carbon nanotube (CntG) incorporation governs the optical band structure and disorder-related phenomena in PMMA/PVP-based nanocomposite films, while critically benchmarking multiple optical band-gap determination methods. PMMA/PVP nanocomposite films reinforced with carbon nanotubes doped with 52 wt% graphene (CntG) were fabricated via spin coating using varying nanofiller volume fractions, and their optical responses were investigated through UV–Vis absorbance and reflectance spectroscopy. The optical band gap (Eg) was evaluated and comparatively analyzed using six independent approaches, including Tauc, Absorption Spectrum Fitting (ASF), Kubelka–Munk, derivative-based, and dielectric-loss methods, providing a comprehensive assessment of methodological consistency. Increasing CntG content resulted in enhanced UV absorption, a pronounced redshift of the absorption edge, and a systematic narrowing of Eg, attributed to the formation of localized electronic states and improved charge-transfer pathways within the hybrid polymer matrix. SEM and FTIR analyses confirmed homogeneous dispersion of CntG and strong polymer–nanocarbon interfacial interactions, leading to a corrugated layered morphology. The Urbach energy (Eu), calculated using two independent approaches, increased markedly with CntG loading, indicating enhanced structural disorder and band-tail broadening. Furthermore, refractive index, dielectric constant, and extinction coefficient increased systematically with nanofiller content, demonstrating the tunability of the nanocomposite's optoelectronic response. Overall, this work establishes PMMA/PVP/CntG nanocomposites as promising materials for advanced photonic, optoelectronic, UV-absorbing, and electromagnetic-wave–management applications, while offering a robust multi-method benchmark for reliable optical bandgap determination in polymer-based nanocomposites.