Dielectric properties of Ti3C2Tx MXene/polyvinyl alcohol composites
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摘要: 以二维过渡金属碳化物Ti3C2Tx MXene作为填料,非铁电、可生物降解的高分子物质聚乙烯醇(PVA)作为基体,通过溶液涂膜法制备了具有高介电常数的Ti3C2Tx MXene/PVA柔性复合材料。研究了Ti3C2Tx MXene充填量对复合材料介电性能的影响。Ti3C2Tx MXene/PVA复合材料的介电性能变化遵循逾渗规律,随着Ti3C2Tx MXene充填量的增加,Ti3C2Tx MXene/PVA复合材料的介电常数呈先增加后减小的变化规律,Ti3C2Tx MXene充填量为20wt%的Ti3C2Tx MXene/PVA复合材料介电常数在20 Hz时高达577.3,比纯PVA的介电常数(10.5)提升了5 398%。但是,当Ti3C2Tx MXene充填量超过20wt%后,Ti3C2Tx MXene/PVA复合材料的介电常数急剧下降,介电损耗快速上升,表现出明显的逾渗行为。Abstract: Flexible Ti3C2Tx MXene/polyvinyl alcohol (PVA) composites with high dielectric constant were fabricated by using the solution casting method with two-dimensional transition metal carbide Ti3C2Tx MXene as the filler and non-ferroelectric and biodegradable polyvinyl alcohol (PVA) as the matrix. The effect of Ti3C2Tx MXene loading on the dielectric properties of the composites were investigated. The variation of dielectric properties of the Ti3C2Tx MXene/PVA composites conforms to the percolation theory. With the increase of Ti3C2Tx MXene loading, the dielectric constant of Ti3C2Tx MXene/PVA composites first increases and then decreases. The composites show a dielectric constant up to 577.3 at 20 Hz frequency with Ti3C2Tx MXene loading of 20wt%, a 5 398% increase compared with that of the neat PVA matrix. When the Ti3C2Tx MXene loading exceeds 20wt%, the dielectric constant of the Ti3C2Tx MXene/PVA composites decreases sharply and the dielectric loss increases rapidly, showing obvious percolation behavior.
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Key words:
- Ti3C2Tx /
- MXene /
- polyvinyl alcohol /
- dielectric constant /
- dielectric loss
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图 2 Ti3C2Tx MXene/PVA复合材料的光学照片 (a),10wt% Ti3C2Tx含量复合薄膜表面 (b)、20wt% Ti3C2Tx含量复合薄膜表面 (c)、20wt% Ti3C2Tx含量复合薄膜断面 (d) 的FE-SEM图像及XRD图谱 (e)
Figure 2. Optical photograph of Ti3C2Tx MXene/PVA composites (a), FE-SEM images of surface of the composite films with 10wt% Ti3C2Tx (b), surface of the composite films with 20wt% Ti3C2Tx (c) and cross-section of the composite films with 20wt% Ti3C2Tx (d) and XRD patterns of Ti3C2Tx MXene/PVA composites (e)
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