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Herein, investigation on XLPE-Al2O3-clay ternary hybrid systems of Al2O3 and clay in 1 : 1 and 2 : 1 ratios, binary systems of XLPE-clay and XLPE-Al2O3 nanocomposites, with special reference to the hybrid filler effect and the superior microstructural development in ternary systems is conducted. The ternary hybrid composite of Al2O3 and clay in a 1 : 1 ratio exhibits the highest tensile strength (100% increase) and Young's modulus (208% increase), followed by the Al2O3 : clay = 2 : 1 system. The interaction between alumina and clay altered the composite morphology, filler dispersion and gave rise to a unique filler architecture leading to a substantial boost up in mechanics compared to predictions based on the idealized filler morphology. Experimentally observed much higher mechanics compared to theoretical predictions confirmed that the dramatic improvement in mechanics is the outcome of the positive hybrid effect and a second factor of synergism, i.e. filler-filler networks. Morphological control of the hybrid filler network is realized by adjusting the ratio between different fillers. For the Al2O3 : clay = 2 : 1 system, the microstructural limitation of dispersion due to the steric effect of alumina clusters shifts the properties to the negative hybrid effect region.

Scientific advancements in the field of high-power transmission and distribution of electrical energy revolutionized the field of high-performance polymer-based electrical insulation systems. Cross-linked polyethylene (XLPE) and its nanocomposites have gained substantial attention in the area of insulation, and these materials play a prodigious role in the arena of cable insulation. This paper includes various strategies for cross-linking PE coupled with different nanofillers to enhance the electrical insulation properties to attain high power transmission. It summarizes the significance of SiO 2 -, alumina-, TiO 2 -, and MgO-based XLPE nanocomposites as potential candidates for insulation in high voltage cables, electrical chips, and transistors and boron nitride-based XLPE nanocomposites for thermal insulation applications. Major challenges in dielectric insulation for cables, like partial discharge, space charge accumulation, water trees, volume resistivity, and DC breakdown strength, are addressed.

Summary Wetting properties and surface energy characteristics of cross‐linked polyethylene (XLPE) with different nanofillers (such as Al2O3, SiO2, TiO2, and clay) were studied using contact angle measurements with water and dimethyl sulfoxide (DMSO) as solvents. Similar trend of variation of contact angle was found for both the kinds of systems. In nanocomposites, the high packing density of the macromolecules on the super molecular level (with marked ordering even in quasi‐amorphous regions) create steric and kinetic hindrances for penetration of solvent molecules, which may result in high degree of solvent resistance, confirmed by the transition of the material from wetting region (for neat XLPE) to a non‐ wetting region (for nanocomposites). Results of contact angle studies have been correlated with the morphology and microstructure development in each system by electron microscopy.

Transport properties of hybrid nanoparticle based cross-linked polyethylene (XLPE)-Al2O3-clay binary and ternary nanocomposites have been investigated with special significance to the hybrid effect and synergism of hybrid nanofillers. Compiling the temperature and filler effects demonstrates the self-assembly of hybrid nanofillers in confining the polymer chain dynamics. Studies on transport mechanisms, transport coefficients, and swelling parameters confirm the superior solvent resistant properties of hybrid filler reinforced nanocomposites. Experiments confirmed the extra stability of the ternary hybrid nanocomposites against the process of solvent penetration. Thermodynamic and kinetic investigations reveal that the nanofillers are competent to alter the thermodynamic feasibility and rate constant parameters. Theoretical predictions by the Peppas-Sahlin model suggest that the diffusion process is well thought-out to be a combination of diffusion into the swollen polymer and the polymer chain relaxation process. The morphology and the network density estimation confirm the presence of filler networks and the trapped polymer chains inside them, in ternary systems, which elucidate the microstructure assisted solvent resistant properties of the ternary hybrid nanocomposites. The amount of polymer chains immobilized by the filler surface was computed from dynamic mechanical analysis and a nice correlation was established between transport characteristics and the polymer chain confinement.