(161e) Solvent Effects On Conjugated Polymer Nanotubule Fabrication Via Template Wetting

Template wetting is one of the simplest approaches to polymer nanofabrication. Like other solution based polymer processing methods, it is reasonable to expect that the choice of solvent will have a significant impact on the chain orientation in the final solid structure. A significant redshift in the Uv-vis absorption of MEH-PPV nanotubules has been observed in comparison to thin films, indicating an increased effective conjugation length and greater molecular order in the nanostructured material. The degree of this bathochromic shift has been found to be dependent on the solvent used in the wetting solution. Similarly, hole mobility was measured in simple nanotubule based electronic devices and found to depend on the choice of solvent. Both the redshift in the electronic absorption band and increase in mobility were found to correspond to the degree of polymer alignment as determined from polarized FTIR spectroscopy. All of these properties were found to correspond most strongly with the rate of evaporation of the solvent as measured using thermogravimetric analysis.