Surlyn(R)/silicate hybrid materials were produced via diffusion-controlled polymer in situ sol-gel reactions for tetraethylorthosilicate. The heterogeneous morphologies of these materials were inspected with transmission electron (TEM), atomic force (AFM), and environmental scanning electron microscopic methods. The silicate uptake was highly dependent on the water affinity of the particular Surlyn(R) form (acid or ionic) rather than on the affinity of the solvent. The morphology consisted of silicate particles with diameters that were on the order of tens of nanometers. Hence, these materials can be classified as nanocomposites. The particle size distributions in both the TEM and AFM images for all composites appeared to be narrow, with un-neutralized Surlyn(R) exhibiting a broader distribution. Larger particles were found near the film surfaces, and the silicon elemental distribution across the film thickness indicated higher concentrations near the surfaces, which is most likely due to the fact that the sol-gel reaction is diffusion controlled in these polymeric media. (C) 2003 Wiley Periodicals, Inc.