1. Nanostructural characterization of luminescent polyvinyl alcohol/graphene quantum dots nanocomposite films
- Author
-
Elumalai, Dhanumalayan, Rodríguez Fernández, Beatriz, Kovtun, Ganna, Hidalgo Alcalde, Pedro, Méndez Martín, María Bianchi, Kaleemulla, Shaik, Joshi, Girish M, Cuberes, M. Teresa, Elumalai, Dhanumalayan, Rodríguez Fernández, Beatriz, Kovtun, Ganna, Hidalgo Alcalde, Pedro, Méndez Martín, María Bianchi, Kaleemulla, Shaik, Joshi, Girish M, and Cuberes, M. Teresa
- Abstract
2023 Descuentos MDPI, This study focuses on the fabrication of polymer nanocomposite films using polyvinyl alcohol (PVA)/graphene quantum dots (GQDs). We investigate the relationship between the structural, thermal, and nanoscale morphological properties of these films and their photoluminescent response. Although according to X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and differential thermal analysis (DTA), the incorporation of GQDs does not significantly affect the percentage crystallinity of the PVA matrix, for a range of added GQD concentrations, atomic force microscopy (AFM) showed the formation of islands with apparent crystalline morphology on the surface of the PVA/GQD films. This observation suggests that GQDs presumably act as nucleating agents for island growth. The incorporation of GQDs also led to the formation of characteristic surface pores with increased stiffness and frictional contrast, as indicated by ultrasonic force microscopy (UFM) and frictional force microscopy (FFM) data. The photoluminescence (PL) spectra of the films were found to depend both on the amount of GQDs incorporated and on the film morphology. For GQD loads >1.2%wt, a GQD-related band was observed at similar to 1650 cm(-1) in FT-IR, along with an increase in the PL band at lower energy. For a load of similar to 2%wt GQDs, the surface morphology was characterized by extended cluster aggregates with lower stiffness and friction than the surrounding matrix, and the PL signal decreased., Universidad de Castilla La Mancha, Fondo Europeo de Desarrollo Regional (Unión Europea), Ministerio de Ciencia e Innovación (España), Unión Europea, Comunidad de Madrid, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub
- Published
- 2024