Photoactive Nanostructures of Polypyrrole

Abstract

The creation of nanostructures of the photoactive polymer polypyrrole (PPy) on glass substrates with the spin-coating method is described. No additional post-production treatment is necessary to obtain uniformly distributed photoactive nanostructures on macroscopically scaled substrates. Based on X-ray reflectivity measurements, the critical solution concentration of PPy below which these nanostructures develop is determined. The PPy nanostructures are displayed with atomic force microscopy (AFM) measurements, which prove that the nanostructures form directly on the substrate. With UV/Vis spectroscopy the absorption behavior of the nanostructures is probed in comparison to PPy films and PPy solutions. A linear dependence of the absorption of the nanostructure on the surface coverage measured with AFM is detected. The influence of confinement on the conjugation length results in a modified absorption behavior of the nanostructures.

Influence of Annealing and Blending of Photoactive Polymers on Their Crystalline Structure

“…In this regime the concentration-dependent thickness stays still linear but the slope is increasing. We found such behavior already for various conjugated polymers. , A simplified model which illustrates the film formation process during spin coating is described elsewhere …”

Bulk synthesis, optimization, and characterization of highly dispersible polypyrrole nanoparticles toward protein separation using nanocomposite membranes

“…6c). The increased absorbance at large wavelengths and a shift of the k max toward larger wavelengths are due to the increased conjugation length for PPy in the nanoparticles, as previously reported for nanostructured PPy thin films [35]. This also explain that the PPy nanoparticles exhibited an increased conductivity (3.0 Â 10 À6 S/cm vs. 1.1 Â 10 À2 S/cm).…”

CuBr2‐induced charge screening on photoactive nanocolloidal polypyrrole:poly(styrene sulfonate) composite multilayer thin‐film counter electrodes for high‐efficiency dye‐sensitized solar cells

“…Moreover, counterion exchange from PSS − to Br − results in a moderate redshift in the absorption maximum ( ca 10 nm) for all PPyCB films (Figs S2–S4 in the supporting information). It is worth mentioning here that the peak shift is due to CuBr 2 treatment which is an indication of increased conjugation length of PPy molecules in the multilayer films . PPy with longer conjugation length will have a smaller band gap .…”

“…It is worth mentioning here that the peak shift is due to CuBr 2 treatment which is an indication of increased conjugation length of PPy molecules in the multilayer films . PPy with longer conjugation length will have a smaller band gap . Also, during CuBr 2 salt treatment the anions would affect the multilayer PPy:PSS films and induce the loss of PSS from them.…”