Rementer, Paul. Solvent effects on the thermal and spectroscopic properties of poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene) (meh-ppv) thin films. Retrieved from https://doi.org/doi:10.7282/T3FX77WN
DescriptionIn 1990, Poly (phenylene vinylene) (PPV) became the first conjugated polymer used in polymer electroluminescent devices.6 With the addition of alkoxy side chains, the PPV derivative poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene) (MEH-PPV) was able to be processed in many common organic solvents. However, it soon became apparent that the conditions under which MEH-PPV devices and thin films were prepared had a great effect on their morphology and electronic properties. Most notably, the choice of solvent used, whether aromatic or aliphatic, had the greatest effect on these properties. Many research groups have studied the effects of different solvents and processing conditions on fluorescence, absorption and device operation. Very little research has been conducted however on how these different morphologies affect the thermal and mechanical properties of the thin films. A differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA) and differential mechanical analyzer (DMA) were used to observe the correlation between solvent choice and casting conditions on the thermal and mechanical properties of MEH-PPV thin films. Infrared spectroscopy (IR) was used to verify the quality of the cast films, as well as look for any shifts in the absorbance bands that changes in the morphology or residual solvents would create. Lastly, a spectrofluorophotometer was used to gain a better understanding of how the emission band wavelengths are affected by factors such as solvent choice and conditions used for casting: under air atmosphere, under argon, in vacuum desiccators (under vacuum).