- Change in conformation of polymer PFO on addition of multiwall carbon nanotubes.
Change in conformation of polymer PFO on addition of multiwall carbon nanotubes.
Multiwall carbon nanotubes (MWNTs) have been added to the polymer poly (9,9-dioctylfluorenyl-2, 7-diyl) end capped with dimethylphenyl (PFO) in various weight percentages and the blends thus prepared, using a solution processing approach, have been characterized using SEM, UV-VIS spectroscopy, PL spectroscopy and I-V characterization. The SEM micrographs show a change in the structure of the polymer from partially crystalline to a glassy state in the blend form. The morphology observations are supported by absorption spectra which show a very high diminution of the polymers' beta peak in the spectra obtained from the polymer-nanotube blend. Thus, multiwall carbon nanotubes modify the local nanoscopic structure of PFO leading to a more glassy structure instead of a partially crystalline form and provide a method to tailor the conformation of polymer PFO, depending on intended application. I-V characteristics reveal an increase in current on formation of the polymer-nanotube blend as compared to the polymer-only structure. On the basis of percolation theory, as applied to these polymer-nanotube blends, a percolation threshold value of 0.45 wt% and critical exponent value of 1.84 has been obtained, indicating the formation of a three dimensional polymer-nanotube network.