Electron microscopy of multi-layered polymer-nanocomposite based dielectrics

Electron Microscopy and Analysis Group Conference 2013

Mahadevegowda, Amoghavarsha^1 ; Young, Neil P.^1 ; Grant, Patrick S.^1

Department of Materials, University of Oxford, Parks Road, OX1 3PH Oxford, United Kingdom^1

关键词: Al-nanoparticles;    Charge accumulation;    Continuous films;    Dielectric behaviour;    Impedance spectroscopy;    Microstructural characterisation;    Particle surface area;    Polymer nanocomposite;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/522/1/012041/pdf
DOI  :  10.1088/1742-6596/522/1/012041

来源: IOP

【 摘 要 】

Vacuum deposited polymer-nanocomposites (PNCs) comprising alternate layers of metal (Al/Ag) (filler) and polymer (nylon-6) (matrix) have been investigated using chemical, impedance spectroscopy and microstructural characterisation techniques. Electron microscopy investigations revealed the morphology, nanostructure and phases of nano-scale core (metal)-shell (oxide) particles and metallic nano-islands in Al and Ag based PNCs respectively. Evaporation of Al yielded islands of angular core-shell nanoparticles in an Al-oxide/nylon-6 matrix whereas Ag yielded rounded, discrete nanoparticles in nylon-6 matrix. The high particle surface area and an affinity for oxygen formed oxide shells in Al nanoparticles and was critical to charge accumulation and enhanced dielectric behaviour; in contrast, Ag showed little oxidation and less charge accumulation. With an increase in the thickness of the deposited metal layer, Al formed a continuous film of particles whereas Ag condensed to form interconnected nano-islands. This microstructural study is useful in conceptualising better dielectrics based on PNCs.