Elumalai Dhanumalayan, Rodríguez Beatriz, Kovtun Ganna, Hidalgo Pedro, Méndez Bianchi, Kaleemulla Shaik, Joshi Girish M, Cuberes M Teresa
Department of Applied Mechanics and Project Engineering, Mining and Industrial Engineering School of Almaden, University of Castilla-La Mancha, 13400 Almadén, Spain.
Thin Films Laboratory, Center for Functional Materials, Vellore Institute of Technology, Vellore 632014, Tamilnadu, India.
Nanomaterials (Basel). 2023 Dec 19;14(1):5. doi: 10.3390/nano14010005.
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 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.
本研究聚焦于使用聚乙烯醇（PVA）/石墨烯量子点（GQDs）制备聚合物纳米复合薄膜。我们研究了这些薄膜的结构、热性能和纳米级形态特性与其光致发光响应之间的关系。尽管根据X射线衍射（XRD）、傅里叶变换红外光谱（FT-IR）和差热分析（DTA），GQDs的掺入对PVA基体的结晶度百分比没有显著影响，但对于一系列添加的GQD浓度，原子力显微镜（AFM）显示在PVA/GQD薄膜表面形成了具有明显结晶形态的岛状物。这一观察结果表明，GQDs可能充当了岛状物生长的成核剂。如超声力显微镜（UFM）和摩擦力显微镜（FFM）数据所示，GQDs的掺入还导致形成了具有增加的刚度和摩擦对比度的特征性表面孔隙。发现薄膜的光致发光（PL）光谱既取决于掺入的GQDs的量，也取决于薄膜形态。对于GQD负载>1.2%wt，在FT-IR中约1650 cm处观察到与GQD相关的谱带，同时在较低能量处的PL谱带增加。对于约2%wt GQDs的负载，表面形态的特征是形成了比周围基体具有更低刚度和摩擦的扩展簇聚集体，并且PL信号降低。
Zotero 插件
