On Interfaces and the DC Breakdown Performance of Polyethylene/Silica Nanocomposites

In this paper, the mechanisms underpinning the concept of filler functionalization in nanodielectrics was studied through the use of silane coupling agents containing different aliphatic chain lengths. The results agree with our previous findings that the use of nanosilica functionalized using long silane chains enhances the DC breakdown performance of the resulting nanocomposites, but the optimized breakdown strength depends not only on the silane chain length - other factors such as the degree of filler functionalization are also believed to be influential. At present, few systematic studies of this area have been undertaken with a view to understanding the mechanisms underpinning the concept of filler functionalization in nanodielectrics, and this work demonstrates a promising way to tailor the properties of polyethylene-based nanodielectrics via silanes with different alkyl chain lengths. Several key questions concerning nanodielectric research are also raised.