Tuning Aggregation of Poly(3-hexylthiophene) within Nanoparticles

Abstract

Nanoparticles derived from π-conjugated polymers have gained widespread attention as active layer materials in various organic electronics applications. The optoelectronic, charge transfer, and charge transport properties of π-conjugated polymers are intimately connected to the polymer aggregate structure. Herein we show that the internal aggregate structure of regioregular poly(3-hexylthiophene) (P3HT) within polymer nanoparticles can be tuned by solvent composition during nanoparticle fabrication through the miniemulsion process. Using absorption spectra and single-NP photoluminescence decay properties, we show that a solvent mixture consisting of a low boiling good solvent and a high boiling marginal solvent results in polymer aggregate structure with a higher degree of uniformity and structural order. We find that the impact of solvent on the nature of P3HT aggregation within nanoparticles is different from what has been reported in thin films.

Poly(3-hexylthiophene) Nanoparticles Containing Thiophene-S,S-dioxide: Tuning of Dimensions, Optical and Redox Properties, and Charge Separation under Illumination

“…2Ba, 2Bb black line), attributable to a higher degree of intra-and interchain order. 36,46,47 As shown in Figure 2B, going from P3HT-NPs to the more oxygenated PTDO-NPs, a blue-shift in the maximum of the absorption spectra ( Fig. 2Ba) and a progressive decrease in the intensity of the fluorescence emission (Fig.…”

Interfacial Crystallization‐Driven Assembly of Conjugated Polymers/Quantum Dots into Coaxial Hybrid Nanowires: Elucidation of Conjugated Polymer Arrangements by Electron Tomography

“…However, when both the solution-biphase and one-pot addition methods were used in chloroform/acetonitrile mixture, vibronic shoulders appeared at 471, 550, and 603 nm, which were assigned as the A 0-2 , A 0-1 , and A 0-0 , respectively, and indicated the formation of crystalline aggregates. [48][49][50] The fraction of P3HT-b -P2VP aggregates is shown in Table 1 , which was obtained by using the approach described by Clark et al (Figure S13, Supporting Information). [ 51 ] The amount of aggregated chains produced by the one-pot addition method decreased slightly compared to that produced by the solution-biphase method.…”

“…Also, the W of hybrid NWs formed by solution-biphase method (0.136 eV) was smaller than that of the NWs produced by the one-pot addition method (0.152 eV, Table 1 ), indicating a decrease in the torsional disorder and an increase in the conjugation length of P3HT within the hybrid NWs. [ 46,47,50 ] Interestingly, the W value of the short hybrid NWs with low crystallinity produced by the one-pot addition method decreased from 0.152 to 0.147 eV after aging for 5 d ( Table 1 ), indicating that the P3HT-based CPs within the NWs were rearranged cofacially to become more well ordered. As mentioned before, the TEMT results of the NWs prepared by the one-pot addition showed an increase in coaxiality and elongation of the NWs as the annealing time was increased (Figure 3 b,c).…”

“…[ 46,50 ] The measured absorption spectra are composed of a high-energy region attributed to unaggregated chains and a low-energy region originated from the vibronic structure of aggregated chains. The absorption spectrum was decomposed into a scaled unaggregated chains in chloroform solution (gray solid line), and aggregate spectrum (dash dot line).…”

Synthesis and self-assembly of fluorene-vinylene alternating copolymers in “Hairy-Rod” architecture: side chain – mediated tuning of conformation, microstructure and photophysical properties

“…[60] It was hypothesized that, in good solvents, the side chains will adopt the most extended conformation, which should prevent the conjugated chain aggregation even in the conditions of spatial constraints imposed by the supramolecular entities formed via Sa. [61] The method used for Sa is the so-called 'direct dissolution method' that was reported as an appropriate approach for both amphihilic [12] and non-amphiphilic [62] rod-coil copolymers. To prove solvent-induced Sa of the reported materials, DLS measurements of the solutions and aFM analysis for the films obtained from these solutions were conducted.…”