OICC Press International Nano Letters 2228-5326 15 1 2025 03 31 PMMA/TiO₂ Nanocomposite Derived Selective Surface Coatings for Improved Optical Properties with Cold Plasma Assisted 10.57647/inl.2025.1401.02 EN Rasheed N. Abed Department of Mechanical Engineering, College of Engineering, Al-Nahrain University, P.O. Box: 64040, Jadriyah, Baghdad, Iraq https://orcid.org/0000-0001-5196-617X Hassan Hashim Department of Medical Physics, College of Science, Al-Nahrain University, P.O. Box: 64021, Jadriyah, Baghdad, Iraq Muataz Ali Department of Chemistry, College of Science, Al-Nahrain University, P.O. Box: 64021, Jadriyah, Baghdad, Iraq Roaa T. Abdulla Department of Physics, College of Science, Al-Nahrain University, P.O. Box: 64021, Jadriyah, Baghdad, Iraq Ali B. M. Ali Air conditioning Engineering, Faculty of Engineering, Warith Al-Anbiyaa University, Karbala 56001, Iraq Mohammed Al-Baidhani Department of Physics, College of Science, Al-Nahrain University, P.O. Box: 64021, Jadriyah, Baghdad, Iraq Kadhim A. Aadim Department of Physics, College of Science, University of Baghdad, Baghdad, Iraq Abdulrahman H. Shaker Department of Physics, College of Science, University of Baghdad, Baghdad, Iraq Khalid Zainulabdeen Department of Chemistry, College of Science, Al-Nahrain University, P.O. Box: 64021, Jadriyah, Baghdad, Iraq Ahmed A. Alamiery Al-Ayen Scientific Research Center, Al-Ayen Iraqi University, AUIQ, Al-Nasiriyah, P.O. Box: 64004, Thi Qar, Iraq Muna S. Bufaroosha Department of Chemistry, College of Science, United Arab Emirates University, Al-Ain, United Arab Emirates Emad Yousif Department of Chemistry, College of Science, Al-Nahrain University, P.O. Box: 64021, Jadriyah, Baghdad, Iraq Journal Article 2025 03 31 Progressive evolution of nanostructured coatings with costume-made structural and optical properties is of major interest for different high-tech applications. This work targeted the incorporation of titanium dioxide (TiO₂) nanoparticles to poly(methyl methacrylate) (PMMA) nanocomposite films across three concentrations (1%, 2%, and 3%) using the casting method. These films were later treated with cold dielectric barrier discharge (DBD) plasma to refine their structure and optical properties. Investigations were systematically studied through the work including the extinction coefficient, absorption coefficient, dielectric constant (real and imaginary), energy gap, Urbach energy, and refractive index. A significant increase resulted in the real dielectric constant, refractive index, and absorption coefficient, on the other hand, a decrease due to strong absorption was noted in the imaginary dielectric constant and extinction factor. Direct and indirect energy gap ranged from 4.7 to 4.5 eV, and 3.4 to 3.25 eV, respectively. Urbach energy data elevated from 366 to 395 meV, which suggests improved charge carrier transport attributed to structural modifications achieved by plasma induction. Also, cold DBD plasma treatment efficiently increased the roughness of the surface, and as a result, improved the film's optical absorption abilities. These findings were confirmed using structural analysis, X-ray diffraction (XRD) showed a mixture of semi-crystalline and amorphous phases. SEM examined revealed a uniform TiO₂ distribution across the PMMA accompanied by gaining a roughened morphology. AFM analysis also showed a boost in surface roughness from 0.828 to 3.04 nm after incorporating TiO₂ and applying plasma treatment. These results propose that PMMA/TiO₂ nanocomposite films showed encouraging potential for applications in fiber optics, optical sensors, photocatalysis, and light-emitting diodes (LEDs). Highlights ·       The study targeted the incorporation of titanium dioxide (TiO₂) nanoparticles into poly(methyl methacrylate) (PMMA) nanocomposite films across three concentrations (1%, 2%, and 3%) using the casting method. ·       The investigations were systematically studied through the work, including the optical properties and Urbach energy. ·       The direct and indirect energy gap decreased from 4.7 to 4.5 eV, and from 3.4 to 3.25 eV, respectively. Urbach energy data elevated from 366 to 395 meV, suggesting an improvement in charge carrier transport due to structural modifications achieved by plasma induction. ·       The SEM examination revealed a uniform TiO₂ distribution across the PMMA accompanied by a roughened morphology. AFM analysis also showed a boost in surface roughness from 0.828 to 3.04 nm after incorporating TiO₂ and applying plasma treatment. ·       The innovative results of PMMA/TiO₂ nanocomposite films showed encouraging potential for applications in fiber optics, optical sensors, photocatalysis, and light-emitting diodes (LEDs).