Organic/inorganic nanocomposites and methods for their preparation are disclosed. In one embodiment, the method comprises the steps of providing an organic/inorganic concentrate and processing the concentrate with a polymer resin. In a preferred embodiment the organic/inorganic concentrate and polymer resin are processed by extrusion using a single-screw extruder. In another embodiment, the method further comprises surface modifying an inorganic additive, mixing the modified additive with a polymer solution to produce an organic/inorganic solution, and removing solvent from the organic/inorganic solution to produce the organic/inorganic concentrate. Processing of the organic/inorganic concentrate with a polymer resin produces a homogeneous nanocomposite with superior mechanical and thermal properties.