Session L36 - General Poster Session II.
POSTER session, Wednesday morning, March 22
Exhibit Hall, MCC
The morphology and structure of gradient copolymers of poly[(styrene-r-maleic anhydride)-b-polystyrene] were investigated. Reflection optical microscopy images showed continuous color changes at the edge of the spin-coated thin films indicating that a layering of the morphology parallel to the substrate interface did not occur. Microphase separation was observed by atomic force microscopy measurements on reactive ion etched samples, which showed cylindrical microdomains oriented normal to the surface. The cylinder-cylinder separation distance was about 16nm, consistent with bulk values determined by x-ray scattering. No interference maxima were seen in neutron reflectivity experiments over a temperature range from 130^oC to 190^oC, suggesting a vertical orientation of the cylinders. The surface tension of the gradient copolymer was slightly higher than that of PS. The combined control over the orientation of the microdomains with the ability to convert the anhydride to the corresponding acid makes the materials interesting candidates for functional nanascopic arrays.