Enhancing the Elasticity of Conjugated Polymers through Precise Control of the Spacing between the Backbone and Siloxane Side-Chains

Abstract

Intrinsically stretchable conjugated polymers (CPs) have extensively been studied for the development of novel flexible electronic devices. In this work, a method to control the elastic properties of CPs has been proposed via regulation of spacer length between the siloxane side-chain and the backbone. The target polymers were CP films with the structure P­(mC–Si) for four different numbers of the spacer methylene groups, namely, m = 5, 6, 7, and 8. The effect of spacer length on the aggregation state as well as on electrical and elastic properties of the prepared films was then investigated. An adjustable lamellar spacing (d L–L), in addition to improved elastic properties, was achieved as the spacer length was changed in the prepared polymer films. Moreover, P­(7C–Si) has a sufficient d L–L value of 35.77 Å, which provides enough space for inter-chain sliding to dissipate stress. This facilitated the dissipation of stress during the straining process. At a strain value of 100% in the vertical direction, the mobility of the P­(7C–Si) film was 0.79 cm2 V–1 s–1 and reduced to 84.0% of the initial value without any applied strain. The study provides clear evidence that tuning the spacer length between the silicone endgroup and backbone is an effective way to improve the intrinsic stretchability of CPs with siloxane side chains.

A hydrogen bonded azine as a building block for π-conjugated polymers and their semiconducting properties

“…The solution absorption spectra of the polymers showed pronounced shoulders, indicating strong intermolecular aggregations even in dilute solutions. 33 The P1 solution exhibited a λ max at 596 nm with a molar extinction coefficient of 1.31 × 10 5 M −1 cm −1 , P2 showed a λ max at 763 nm with a molar extinction coefficient of 1.17 × 10 5 M −1 cm −1 , and P3 showed a λ max at 559 nm with a molar extinction coefficient of 1.00 × 10 5 M −1 cm −1 (Fig. S4†).…”

Additive engineering for high-performance polythiophene gas sensors incorporating functional amine additive with strong binding energy for NO2

“…29 The intensity of the A 0-0 and A 0-1 bands increased slightly with the addition of DETA owing to crystallization; however, the thicknesses of the P3HT thin films were almost the same. [30][31][32] When a small amount of DETA was added (o20 wt%), the P3HT thin film had a homogeneous structure; however, when a large amount of DETA was added (420 wt%), P3HT precipitated, causing many defects in the thin film and increasing the film roughness (Fig. 2d and e).…”

“…2e). The dynamic gas-sensing performance was examined by exposing the sensor to NO 2 gas at various concentrations (10,20,30,40, 50 ppm) (Fig. 3e), and the responsivity was calculated as a function of the NO 2 concentration (Fig.…”

Intrinsically stretchable organic field-effect transistors: progress and challenges

“…The main strategies are main-chain or side-chain engineering of polymer semiconductors or the selection of the appropriate copolymerization monomers. 34,76–78 For example, branched urethane side chains were synthesized in diketopyrrolopyrrole (DPP)-based polymers. 64 Under stretching, side chains acted as dynamic bonding moieties to release stress and improve film stretchability.…”