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Elumalai D, Rodríguez B, Kovtun G, Hidalgo P, Méndez B, Kaleemulla S, Joshi GM, Cuberes MT. Nanostructural Characterization of Luminescent Polyvinyl Alcohol/Graphene Quantum Dots Nanocomposite Films. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 14:5. [PMID: 38202460 PMCID: PMC10780860 DOI: 10.3390/nano14010005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 12/10/2023] [Accepted: 12/15/2023] [Indexed: 01/12/2024]
Abstract
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 ~1650 cm-1 in FT-IR, along with an increase in the PL band at lower energy. For a load of ~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.
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Affiliation(s)
- Dhanumalayan Elumalai
- Department of Applied Mechanics and Project Engineering, Mining and Industrial Engineering School of Almaden, University of Castilla-La Mancha, 13400 Almadén, Spain; (D.E.); (G.K.); (G.M.J.)
- Thin Films Laboratory, Center for Functional Materials, Vellore Institute of Technology, Vellore 632014, Tamilnadu, India;
| | - Beatriz Rodríguez
- Department of Physics of Materials, University Complutense of Madrid, 28040 Madrid, Spain; (B.R.); (P.H.); (B.M.)
| | - Ganna Kovtun
- Department of Applied Mechanics and Project Engineering, Mining and Industrial Engineering School of Almaden, University of Castilla-La Mancha, 13400 Almadén, Spain; (D.E.); (G.K.); (G.M.J.)
- Institute of Magnetism NAS of Ukraine and MES of Ukraine, 03142 Kyiv, Ukraine
| | - Pedro Hidalgo
- Department of Physics of Materials, University Complutense of Madrid, 28040 Madrid, Spain; (B.R.); (P.H.); (B.M.)
| | - Bianchi Méndez
- Department of Physics of Materials, University Complutense of Madrid, 28040 Madrid, Spain; (B.R.); (P.H.); (B.M.)
| | - Shaik Kaleemulla
- Thin Films Laboratory, Center for Functional Materials, Vellore Institute of Technology, Vellore 632014, Tamilnadu, India;
| | - Girish M. Joshi
- Department of Applied Mechanics and Project Engineering, Mining and Industrial Engineering School of Almaden, University of Castilla-La Mancha, 13400 Almadén, Spain; (D.E.); (G.K.); (G.M.J.)
- Department of Engineering Physics and Engineering Materials, Institute of Chemical Technology Mumbai, Marathwada Campus, Jalna 431203, Maharashtra, India
| | - M. Teresa Cuberes
- Department of Applied Mechanics and Project Engineering, Mining and Industrial Engineering School of Almaden, University of Castilla-La Mancha, 13400 Almadén, Spain; (D.E.); (G.K.); (G.M.J.)
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