9503626 Ford Polymers filled with glass fibers and silica particles have many commercial applications due to increased hardness, abrasion resistance, tensile modulus, compressive strength, and heat distortion temperature, and to a lower coefficient of thermal expansion. The silica fibers or particles are irregularly dispersed and agglomerated, and the fibers may be oriented by shear. Nothing is known yet about how three- dimensional order of dispersed silica influences the mechanical properties of a composite. We have synthesized the first composites having the dispersed phase ordered as colloidal crystals. During the next grant period we will (1) characterize the crystal structures of the colloidal silica-polymer composites more completely to answer a number of puzzling aspects of the optical diffraction of the films, (2) prepare optical diffraction filters having smaller dispersed particles and a wider range of diffraction wavelengths, (3) prepare tunable filters using elastomeric matrices, (4) prepare blends of colloidal crystals of polystyrene latexes in acrylic matrices as diffraction filters, (5) extend our studies of the optical properties of the colloidal crystalline films to thermal and mechanical properties, (6) characterize the silica-PMMA composites by solid state NMR spectroscopy, and (7) synthesize a new family of colloidal crystalline dispersions in which derivatives of C60 are trapped in polystyrene and and PMMA latexes. %%% This research could lead to the development of several types of novel optical filters and improved elastomers. ***
