Photoactive composite films prepared from mixtures of polystyrene microgel dispersions and poly(3-hexylthiophene) solutions

Abstract

Whilst polystyrene microgels belong to the oldest family of microgel particles, their behaviours when deposited onto substrates or prepared as composites have received little attention. Because polystyrene microgels are solvent-swellable, and inherently colloidally stable, they are well suited to form composites with conjugated polymers. Here, we investigate the morphology and light absorption properties of spin coated composite films prepared from mixed dispersions of polystyrene microgels and poly(3-hexylthiophene) (P3HT) for the first time. We compare the morphologies of the composite films to spin coated microgel films. The films were studied using optical microscopy, SEM, AFM, wide-angle X-ray diffraction and UV-visible spectroscopy. The films contained flattened microgel particles with an aspect ratio of ∼10. Microgel islands containing hexagonally close packed particles were evident for both the pure microgel and microgel/P3HT composite films. The latter were electrically conducting. The composite film morphology was dependent on the microgel and P3HT concentration used for film preparation and a morphology phase diagram was constructed. The P3HT phase acted as an electrically conducting cement and increased the robustness of the films to solvent washing. The composite films were photoactive due to the P3HT component. The absorbance for the films was tuneable and increased linearly with both microgel and P3HT concentration. The results of the study should apply to other organic swellable microgel/conjugated polymer combinations and may lead to new colloidal composites for future optoelectronic applications.

Factors Affecting Peptide Interactions with Surface-Bound Microgels

“…To the best of our knowledge this is the first report of microgel crosssections of MAA-based, non-NIPAM containing microgels, and as shown for other surface adsorbed microgel systems the microgel shape upon binding is flattened. [39][40][41] As shown in Figure 6c and d, the volume of the surface-bound microgel decreases upon peptide uptake and the shape is further flattened. In agreement with the charge ratios obtained in Figure 2b, pLys 1 kDa is most efficient in causing this deswelling, whereas the lower degree of charge neutralization for pLys 10 kDa results in an analogously suppressed deswelling.…”

Reducing hole transporter use and increasing perovskite solar cell stability with dual-role polystyrene microgel particles

“…PS MGs increase structural order and P3HT light absorption within composite P3HT-MG films. 23 The MGs force P3HT to percolate around the particles which preserves conductivity. 23 Here, we greatly extend our earlier approach to include PTAA and Spiro in the context of composite HTMs for PSCs.…”

“…23 The MGs force P3HT to percolate around the particles which preserves conductivity. 23 Here, we greatly extend our earlier approach to include PTAA and Spiro in the context of composite HTMs for PSCs. MG dispersions also have excellent colloid stability 20 and good film forming properties.…”

“…MG dispersions also have excellent colloid stability 20 and good film forming properties. [23][24][25][26] PS MGs are hydrophobic which offers potential for water barrier formation. We hypothesised that MGs could be blended with HTMs to provide improved device stability without substantially compromising device performance.…”

“…We previously reported that mixed MG/P3HT dispersions formed electrically conducting composite P3HT-MG films. 23 Here, we studied PSCs coated with HTM-MG films containing PTAA, P3HT and Spiro and compared their properties. In the second approach, MG films were spin-coated onto a pure P3HT HTM as an encapsulating layer from MG dispersions to give P3HT/ MG(en) PSCs (Fig.…”