Preparation of novel PMMA-NaNbO3-carbon quantum dot composite films for studies of dielectric properties and ac conductivity studies

摘要: The tri-phase PMMA-NaNbO3-CQD composite films consisting of surface hydroxylated sodium niobate and carbon quantum dots as functional filler particles and poly (methyl methacrylate) (PMMA) as polymer matrix were prepared by solution casting technique. The structural, morphological, dielectric, and electric characteristics of tri-phase PMMA-NN-CQD composites at various CQD weight percentages were investigated as a function of frequency. The dielectric characteristics of the PMMA-h-NN-CQD composites exhibit a higher dielectric constant (≈107) and considerably reduced dielectric loss (≈1) at 102 Hz, which is 26 times greater than that of the neat polymer matrix. Furthermore, the PMMA-h-NN-CQD composite demonstrated decreased dielectric loss and higher a.c conductivity. SEM analyses show that the CQD particles were effectively integrated inside the NaNbO3 particles to boost the composite films …