Structural, Morphological, Vibrational, Thermal and Optical Properties of ZnS Quantum Dots in the Polymer Matrix

摘要

Background: Nanotechnology is believed to be a future for new human generations. Among different emerging materials, the Nanocomposites (NCs) would be on front line. The aim of the current study is provide a way to synthesis the ZnS-polyacrylamide NCs with emphasizes on the effect of aging in polymer on its various physical properties. Objectives: To prepare and study the properties of ZnS-Polymer NCs with drying time in polymer matrix. Methods: ZnS-polyacrylamide NCs samples were synthesized by adding aqueous suspension of ZnS Nanoparticles (NPs) in Sol of acrylamide: bisacrylamide copolymer. These samples were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), UV-Vis, and Photoluminescence (PL) spectroscopy. Results: From XRD data analysis, nano phase and zinc blend structure of the material is confirmed. From SEM images, the pristine ZnS NPs show spherical morphology, and this texture is still preserved in the polymer composites. FT-IR confirms that there is strong interaction between polymer chain and ZnS NPs. The TGA results indicate that the incorporation of the NPs impacts the thermal properties of the ZnS-polymer NCs and displaying higher thermal stability than the pure polymer matrix. The optical data predicts the band gap and Quantum Confinement Effect (QCE) and reduction of ZnS NPs within the polymer matrix. These NCs show emission in blue region with decreases in intensity with drying time. Conclusion: ZnS NPs incorporated in polyacrylamide ware prepared by copolymer technique. Structural analysis confirms zinc blend structure. The vibration spectra of composites samples predicts an interaction between different functional groups of polymer with the metal sulfide. These NCs show an enhanced thermally stability. The observed optical band show a red shift and quantum confinement effect. Size calculated by XRD and optical data shows good correlation with each other. The PL spectra of the NCs exhibits a broad blue emission with excitation (A^ = 320 nm). The visible region emission could be originating from the radiative recombination involving defect states within the ZnS nanocrystals energy band.