Internal charge behaviour of nanocomposites

Nelson, J. K. & Fothergill, J. (2004). Internal charge behaviour of nanocomposites. Nanotechnology, 15(5), pp. 586-595. doi: 10.1088/0957-4484/15/5/032

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Abstract

The incorporation of 23 nm titanium dioxide nanoparticles into an epoxy matrix to form a nanocomposite structure is described. It is shown that the use of nanometric particles results in a substantial change in the behaviour of the composite, which can be traced to the mitigation of internal charge when a comparison is made with conventional TiO2 fillers. A variety of diagnostic techniques (including dielectric spectroscopy, electroluminescence, thermally stimulated current, photoluminescence) have been used to augment pulsed electro-acoustic space charge measurement to provide a basis for understanding the underlying physics of the phenomenon. It would appear that, when the size of the inclusions becomes small enough, they act co-operatively with the host structure and cease to exhibit interfacial properties leading to Maxwell-Wagner polarization. It is postulated that the particles are surrounded by high charge concentrations in the Gouy-Chapman-Stern layer. Since nanoparticles have very high specific areas, these regions allow limited charge percolation through nano-filled dielectrics. The practical consequences of this have also been explored in terms of the electric strength exhibited. It would appear that there was a window in which real advantages accrue from the nano-formulated material. An optimum loading of about 10% (by weight) is indicated.

Item Type: Article
Subjects: T Technology > TA Engineering (General). Civil engineering (General)
Divisions: Vice-Chancellor's Portfolio
URI: http://openaccess.city.ac.uk/id/eprint/1382

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