POLY 202 |
| The sequential formation of nanopores in thin film mixtures of asymmetric diblock copolymers of polystyrene-poly(isoprene) and polystyrene-poly(ethylene oxide) was achieved by independent removal of the cylindrical microdomains of the PI and PEO blocks. Thin films were spun cast from solutions of mixtures of the diblock copolymers where the immiscible minor component microphase separated into distinct microdomains. Solvent annealing methods were used to orient the cylindrical microdomains normal to the film surface and to induce lateral ordering of both the PEO and PI cylindrical microdomains. The order, orientation, and miscibility of the PEO and PI cylindrical microdomains were largely dictated by the solvents used in the initial casting solution. Nanopores can be selectively generated by ozone and trifluoroacetic acid etching. This blending and selective etching methodology can be readily applied to other diblock copolymer blends and the resulting nanoporous thin films can be used to fabricate materials containing different nanoscopic elements that are either randomly placed laterally across the film or where there are clusters of distinct element. Such films have potential in optical and solar cell applications. |
|
General Papers: Polymers in Nanotechnology
6:00 PM-8:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster
Sci-Mix
Division of Polymer Chemistry |