Effective dispersion of the fillers in a polymer matrix has been a key challenge in the field of nanocomposites. Supercritical carbon dioxide (scCO2) appears to be a promising technique to achieve high degrees of clay dispersion. The degree to which these clays influence the composite system is a function of their state in the polymer matrix (i.e. intercalated, partially exfoliated, or totally exfoliated), and the strength of the polymer clay interactions. We have prepared PDMS/clay, PS/clay and PVME/clay nanocomposites via scCO2 processing, using natural or organically modified montmorillonite clays. The nanocomposites are characterized using WAXD, SEM, TEM, Rheology and DSC. The high degree of dispersion achieved through sc-CO2 appears to result in an order of magnitude increase in the rheological properties of PS, associated with an increase in the Tg of around 13˚C, at 10% clay loading. These moduli improvements are significant better than those obtained with conventional, chemically-modified intercalated clay nanocomposites. The degree of enhancement in the properties appears to be strongly dependant on the polymer-clay interactions, and how it is promoted by the supercritical fluid. In the case of PDMS nanocomposites, where the clay-polymer interactions were weak, the modulus increase at low frequencies (for sc-CO¬2 processed system) was only a factor of 2. In the case of PVME- I30P clay nanocomposites, the modulus increase was substantial even at moderate loadings and dispersions, perhaps to be hydrogen-bonding interactions. The clay and the polymer orientation and interactions in these nanocomposites are also being probed using rheo-optical FTIR spectroscopy.