The use of polymers as effective solid dielectrics within high voltage equipment has been considered in recent years, with a focus on the dielectric properties of these materials being determined. More recently, it has been suggested that the inclusion of small ratios of nano-structured inorganic compounds, such as silicon and titanium oxides, into the polymer matrix will improve these properties considerably. This project aims to determine the effect on the dielectric and phase properties of thermoplastics (initially amorphous polystyrene) upon the addition of powdered nano-silica over a range of weight ratios. The dielectric constant and breakdown strength will initially be tested, along with the transition point of the materials into the glass phase. The detrimental effects of moisture absorption will also be studied, and the content of these nano-dielectrics will be observed by scanning electron microscope.