Conjugated polyelectrolyte (CPE) interfacial layers present a powerful way to boost the I-V characteristics of organic photovoltaics. Nevertheless, clear guidelines with respect to the structure of high-performance interlayers are still lacking. In this work, impedance spectroscopy is applied to probe the dielectric permittivity of a series of polythiophene-based CPEs. The presence of ionic pendant groups grants the formation of a capacitive double layer, boosting the charge extraction and device efficiency. A counteracting effect is the diminishing affinity with the underlying photoactive layer. To balance these two effects, we found copolymer structures containing nonionic side chains to be beneficial.

Gold nanoparticles stabilized with a thin layer of post-functionalizable calix[4]arenes were prepared through the reductive grafting of a calix[4]arene-tetra-diazonium salt. These particles show exceptional stability towards extreme pH, F(-), NaCl, and upon drying. Post-functionalization of the calix-layer was demonstrated, opening the way to a wide range of applications.

A systematic study of diffusion-controlled reversible Diels−Alder (DA) network formation is performed under both isothermal and nonisothermal reaction conditions based on two amorphous furan−maleimide thermoset model systems. The experimental evolution of the glass-transition temperature, T g , with the predicted DA conversion, x, simulated by a two-equilibrium kinetic model for endo and exocycloadducts leads to the T g −x relationship of these model systems. The heat capacity, c p , from modulated temperature differential scanning calorimetry enables the characterization of (partial) vitrification along the reaction path. In isothermal DA reactions at T cure , a stepwise negative drop in Δc p at the onset of vitrification is observed, followed by a diffusion-controlled reaction at a reduced rate. T g can exceed T cure by at least 15 °C. In nonisothermal DA cure at a sufficiently low heating rate, (partial) vitrification is also possible (negative Δc p step), followed by diffusion-controlled cure until devitrification occurs again (positive Δc p ). Gelation along the reaction path is proven by dynamic rheometry, and gelled glasses can always be obtained under ambient conditions. This information is of importance in the damage management of reversible thermosets by self-repair of microcracks in bulk, as evidenced by dynamic mechanical analysis of a compressed powder after healing below T g .

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Poly(alkylene terephthalate)s represent one of the most frequently used polymer classes worldwide. Well‐known examples include poly(ethylene terephthalate) (n = 2) and poly(butylene terephthalate) (n = 4). The conventional synthesis method for these polymers is based on melt polycondensation, a two‐stage process performed under harsh conditions that includes the synthesis of an intermediate prepolymer and the presence of a catalyst, which may induce toxicity issues. The present work reports on a straightforward single‐step solution polycondensation method performed under mild conditions and in the absence of a catalyst. A homologous series of poly(alkylene terephthalate)s (n = 5 − 10) of molar masses up to 20 000 g mol−1 and dispersity <2.4 was synthesized and characterized thoroughly. Great attention was given to the thermal properties assessment by using state‐of‐the‐art techniques and a highly sensitive prototype technique called rapid heat − cool DSC. Similar to melt‐synthesized polyesters, a particular odd − even trend of the thermal properties versus the number of methylene groups within the monomer unit was revealed. To the best of our knowledge, this is the first report covering a single‐step solution‐based polycondensation performed in the absence of a catalyst that results in highly reproducible polyesters possessing unaltered thermal properties compared to polyesters synthesized through industrially applied conventional routes. © 2017 Society of Chemical Industry