Molecular doping—the use of redox‐active small molecules as dopants for organic semiconductors—has seen a surge in research interest driven by emerging applications in sensing, bioelectronics, and thermoelectrics. However, molecular doping carries with it several intrinsic problems stemming directly from the redox‐active character of these materials. A recent breakthrough was a doping technique based on ion‐exchange, which separates the redox and charge compensation steps of the doping process. Here, the equilibrium and kinetics of ion exchange doping in a model system, poly(2,5‐bis(3‐alkylthiophen‐2‐yl)thieno(3,2‐b)thiophene) (PBTTT) doped with FeCl3 and an ionic liquid, is studied, reaching conductivities in excess of 1000 S cm−1 and ion exchange efficiencies above 99%. Several factors that enable such high performance, including the choice of acetonitrile as the doping solvent, which largely eliminates electrolyte association effects and dramatically increases the doping strength of FeCl3, are demonstrated. In this high ion exchange efficiency regime, a simple connection between electrochemical doping and ion exchange is illustrated, and it is shown that the performance and stability of highly doped PBTTT is ultimately limited by intrinsically poor stability at high redox potential.

Poly(3,4-ethylenedioxythiophene) (PEDOT) is a well-known semiconducting polymer with favorable properties which find it often applied as the active material in biological sensors and electrochromic devices. However, PEDOT has several drawbacks which can prohibit its effective or long-term use, including weak adhesion to substrates such as ITO-coated glass, poorly controlled surface morphology, and reduced electrochemical stability over time. While a diverse range of approaches have been explored to overcome these issues, most involve additives or substrate modification, while solutions based on direct covalent adaptation are relatively lacking. We present a novel polymer based on covalently modified EDOT (PEDOT-Crown), featuring polar motifs and a 15-crown-5 moiety. Compared to PEDOT, PEDOT-Crown demonstrates a wealth of advantageous properties including: superior adhesion to ITO under physical and electrochemical duress; a more uniform surface morphology; and electrochemical properties including a higher contrast ratio, red-shifted polaron and bipolaron absorption features, bleaching of the neutral absorption band across a narrower voltage range, and more Faradaic rather than capacitive behavior. Additionally, we note that in the presence of Na + , PEDOT-Crown appears to show modified behavior in long-term electrochemical experiments. These features make PEDOT-Crown a material with improved suitability for application in biological sensing and electrochromic devices, compared to PEDOT.

Moisture-responsive actuators are widely used as energy-harvesting devices due to their excellent ability to spontaneously and continuously convert external energy into kinetic energy. However, it remains a challenge to sustainably synthesize moisture-driven actuators. Here, we present a sustainable zero-waste emission methodology to prepare soft actuators using carbon nano-powders and biodegradable polymers through a water evaporation method. Due to the water solubility and recyclability of the matrixes employed here, the entire synthetic process achieves zero-waste emission. Our composite films featured strong figures of merit and capabilities with a 250 • maximum bending angle under 90% relative humidity. Programmable motions and intelligent bionic applications, including walkers, smart switches, robotic arms, flexible excavators, and hand-shaped actuators, were further achieved by modulating the geometry of the actuators. This sustainable method for actuators' fabrication has great potential in large-scale productions and applications due to its advantages of zero-waste emission manufacturing, excellent recyclability, inherent adaptive integration, and low cost.

The structure of a self-doping naphthalenetetracarboxylic diimide was found to be the product of unexpected chemical reactions. The effect a mixed chemical composition has on the doped film morphology and electronic performance is also reported.

The introduction of oligoether side chains onto a polymer backbone can help to stabilise polymeric dispersions in water without the necessity of surfactants or additives when conjugated polymer nanoparticles are...