Modified and enhancement polyvinyl alcohol/chitosan (PVA/Cs) films incorporated by hybrid silver tungstate (Ag2WO4) nanoparticles

Q2 Physics and Astronomy
Aysh Y. Madkhli , Lamiaa G. Alharbe
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引用次数: 0

Abstract

This study aims to synthesize silver tungstate (Ag2WO4) nanoparticles and incorporate them into a polyvinyl alcohol/chitosan (PVA/Cs) blend using a casting technique. X-ray diffraction (XRD) analysis confirms the presence of peaks corresponding to silver and tungsten, indicating the presence of these elements in the analyzed samples and providing conclusive evidence of their existence. The XRD profiles also revealed characteristic peaks corresponding to the monoclinic unit cell of PVA and an allomorphic transition within the chitosan structure. After adding Ag2WO4 nanoparticles, XRD analysis exhibited peaks for silver and tungsten with a crystallite size of 42.2 ± 3 nm. The UV–visible measurements indicate that incorporating Ag2WO4 causes a decrease in band gap energy values from 4.71 to 2.38 eV and from 5.8 to 3.73 eV for the direct allowed and direct forbidden transitions, respectively. Furthermore, the optical constants, including the extinction coefficient (k), real (ε), and imaginary (ε) parts, as well as the optical dielectric conductivity, were thoroughly discussed. Photoluminescence (PL) analysis revealed the emergence of a broad band centered at 434 nm with increasing Ag2WO4 concentration, indicating changes in the emission properties of the nanocomposites. The dielectric properties and the electrical modulus (Mʹ) values increased at higher frequencies, indicating charge carrier transfer through short-range mobility. The imaginary part (Mʹʹ) exhibited a peak attributed to dipolar polarization at the interfaces between grains, which experienced a frequency shift towards higher values. This shift indicates alterations in the distribution of Ag2WO4 within the PVA/Cs blend. These nanocomposites show potential in energy storage devices.
杂化钨酸银(Ag2WO4)纳米颗粒改性增强聚乙烯醇/壳聚糖(PVA/Cs)薄膜
本研究旨在合成钨酸银(Ag2WO4)纳米颗粒,并采用铸造技术将其掺入聚乙烯醇/壳聚糖(PVA/Cs)共混物中。x射线衍射(XRD)分析证实了银和钨对应峰的存在,表明所分析样品中存在这些元素,并提供了它们存在的确凿证据。XRD谱图还显示了PVA单斜晶胞的特征峰和壳聚糖结构内的异晶过渡。加入Ag2WO4纳米粒子后,XRD分析显示,银和钨的晶粒尺寸为42.2±3 nm。紫外可见测量结果表明,在直接允许跃迁和直接禁止跃迁的情况下,Ag2WO4的加入使带隙能量值分别从4.71 eV降低到2.38 eV和从5.8 eV降低到3.73 eV。此外,对消光系数(k)、实部(ε′)和虚部(ε″)等光学常数以及光介质电导率进行了深入的讨论。光致发光(PL)分析显示,随着Ag2WO4浓度的增加,在434 nm处出现了以中心为中心的宽带,表明纳米复合材料的发射性能发生了变化。在较高的频率下,介电性能和电模量(M′)值增加,表明电荷载流子通过短程迁移转移。虚部(M′′)在晶粒间界面处出现一个偶极极化峰,并向较高的频率偏移。这种变化表明Ag2WO4在PVA/Cs共混物中的分布发生了变化。这些纳米复合材料在能量存储设备中显示出潜力。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
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来源期刊
Physics Open
Physics Open Physics and Astronomy-Physics and Astronomy (all)
CiteScore
3.20
自引率
0.00%
发文量
19
审稿时长
9 weeks
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