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This review is an attempt to update the recent advances in the self-assembly of amphiphilic block and graft copolymers. Their micellization behavior is highlighted for linear AB, ABC triblock terpolymers, and graft structures in non-aqueous selective polar and non-polar solvents, including solvent mixtures and ionic liquids. The micellar characteristics, such as particle size, aggregation number, and morphology, are examined as a function of the copolymers’ architecture and molecular characteristics.

Developing a high-performance donor polymer is critical for achieving efficient non-fullerene organic solar cells (OSCs). Currently, most high-efficiency OSCs are based on a donor polymer named PM6, unfortunately, whose performance is highly sensitive to its molecular weight and thus has significant batch-to-batch variations. Here we report a donor polymer (named PM1) based on a random ternary polymerization strategy that enables highly efficient non-fullerene OSCs with efficiencies reaching 17.6%. Importantly, the PM1 polymer exhibits excellent batch-to-batch reproducibility. By including 20% of a weak electron-withdrawing thiophene-thiazolothiazole (TTz) into the PM6 polymer backbone, the resulting polymer (PM1) can maintain the positive effects (such as downshifted energy level and reduced miscibility) while minimize the negative ones (including reduced temperature-dependent aggregation property). With higher performance and greater synthesis reproducibility, the PM1 polymer has the promise to become the work-horse material for the non-fullerene OSC community. The batch reproducibility of polymer donor materials limits the performance of polymer solar cells. Here Wu et al. develop a polymer donor PM1 by random terpolymerization strategy with a high efficiency of 17.6% in the device and excellent batch-to-batch reproducibility.

As a key component in stretchable electronics, semiconducting polymers have been widely studied. However, it remains challenging to achieve stretchable semiconducting polymers with high mobility and mechanical reversibility against repeated mechanical stress. Here, we report a simple and universal strategy to realize intrinsically stretchable semiconducting polymers with controlled multi-scale ordering to address this challenge. Specifically, incorporating two types of randomly distributed co-monomer units reduces overall crystallinity and longer-range orders while maintaining short-range ordered aggregates. The resulting polymers maintain high mobility while having much improved stretchability and mechanical reversibility compared with the regular polymer structure with only one type of co-monomer units. Interestingly, the crystalline microstructures are mostly retained even under strain, which may contribute to the improved robustness of our stretchable semiconductors. The proposed molecular design concept is observed to improve the mechanical properties of various p- and n-type conjugated polymers, thus showing the general applicability of our approach. Finally, fully stretchable transistors fabricated with our newly designed stretchable semiconductors exhibit the highest and most stable mobility retention capability under repeated strains of 1,000 cycles. Our general molecular engineering strategy offers a rapid way to develop high mobility stretchable semiconducting polymers. Designing intrinsically stretchable semiconducting polymers with suitable charge transport and mechanical properties required for stretchable electronic devices remains a challenge. Here, the authors report terpolymer-based semiconductors with intrinsically high stretchability and mobility.

Poly(vinylidene fluoride)-based dielectric materials are prospective candidates for high power density electric storage applications because of their ferroelectric nature, high dielectric breakdown strength and superior processability. However, obtaining a polar phase with relaxor-like behavior in poly(vinylidene fluoride), as required for high energy storage density, is a major challenge. To date, this has been achieved using complex and expensive synthesis of copolymers and terpolymers or via irradiation with high-energy electron-beam or γ-ray radiations. Herein, a facile process of pressing-and-folding is proposed to produce β-poly(vinylidene fluoride) (β-phase content: ~98%) with relaxor-like behavior observed in poly(vinylidene fluoride) with high molecular weight > 534 kg mol −1 , without the need of any hazardous gases, solvents, electrical or chemical treatments. An ultra-high energy density (35 J cm −3 ) with a high efficiency (74%) is achieved in a pressed-and-folded poly(vinylidene fluoride) (670-700 kg mol −1 ), which is higher than that of other reported polymer-based dielectric capacitors to the best of our knowledge. Dielectric materials are candidates for electric high power density energy storage applications, but fabrication is challenging. Here the authors report a pressing-and-folding processing of a dielectric with relaxor-like behavior, leading to high energy density in a polymer-based dielectric capacitor.

More than a decade of research on the electrocaloric (EC) effect has resulted in EC materials and EC multilayer chips that satisfy a minimum EC temperature change of 5 K required for caloric heat pumps 1 – 3 . However, these EC temperature changes are generated through the application of high electric fields 4 – 8 (close to their dielectric breakdown strengths), which result in rapid degradation and fatigue of EC performance. Here we report a class of EC polymer that exhibits an EC entropy change of 37.5 J kg −1  K −1 and a temperature change of 7.5 K under 50 MV m −1 , a 275% enhancement over the state-of-the-art EC polymers under the same field strength. We show that converting a small number of the chlorofluoroethylene groups in poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) terpolymer into covalent double bonds markedly increases the number of the polar entities and enhances the polar–nonpolar interfacial areas of the polymer. The polar phases in the polymer adopt a loosely correlated, high-entropy state with a low energy barrier for electric-field-induced switching. The polymer maintains performance for more than one million cycles at the low fields necessary for practical EC cooling applications, suggesting that this strategy may yield materials suitable for use in caloric heat pumps. A study reports and characterizes a high-entropy electrocaloric polymer that switches under low fields, and discusses its potential suitability for use in caloric heat pumps.

The controlled synthesis of terpolymer structures is often limited by the intrinsic reactivities of the monomers. For the synthesis of a statistical terpolymer from cyclohexene oxide (CHO) and propylene oxide (PO) with CO2, an instrumental solution is demanded. Implementing a setup where one monomer can be added to the reaction mixture over the whole course of the reaction, the random distribution of the epoxides over the whole chain is realized. The successful terpolymerization can be determined with diffusion‐ordered nuclear magnetic resonance spectroscopy and gel permeation chromatography measurements while the statistical microstructure of the generated polymers is indicated in NMR spectroscopy and differential scanning calorimetry measurements. Furthermore, the concept is transferred to the terpolymerization of limonene oxide with PO and CO2 underlining the versatility of the setup.

Although the principles of noncovalent bonding are well understood and form the basis for the syntheses of many intricate supramolecular structures, supramolecular noncovalent synthesis cannot yet achieve the levels of precision and complexity that are attainable in organic and/or macromolecular covalent synthesis. Here we show the stepwise synthesis of block supramolecular polymers from metal–porphyrin derivatives (in which the metal centre is Zn, Cu or Ni) functionalized with fluorinated alkyl chains. These monomers first undergo a one-dimensional supramolecular polymerization and cyclization process to form a toroidal structure. Subsequently, successive secondary nucleation, elongation and cyclization steps result in two-dimensional assemblies with concentric toroidal morphologies. The site selectivity endowed by the fluorinated chains, reminiscent of regioselectivity in covalent synthesis, enables the precise control of the compositions and sequences of the supramolecular structures, as demonstrated by the synthesis of several triblock supramolecular terpolymers.Supramolecular structures are typically formed by the one-step self-assembly of building blocks. Now, a greater level of control has been achieved using stepwise non-covalent reactions under kinetic control. Two-dimensional block supramolecular polymers with tailored compositions and sequences were synthesized, and a site selectivity that is reminiscent of regioselectivity in covalent synthesis was observed.

We report the synthesis of three (3) linear triblock terpolymers, two (2) of the ABC type and one (1) of the BAC type, where A, B and C correspond to three chemically incompatible blocks such as polystyrene (PS), poly(butadiene) of exclusively (~100% vinyl-type) -1,2 microstructure (PB1,2) and poly(dimethylsiloxane) (PDMS) respectively. Living anionic polymerization enabled the synthesis of narrowly dispersed terpolymers with low average molecular weights and different composition ratios, as verified by multiple molecular characterization techniques. To evaluate their self-assembly behavior, transmission electron microscopy and small-angle X-ray scattering experiments were conducted, indicating the effect of asymmetric compositions and interactions as well as inversed segment sequence on the adopted morphologies. Furthermore, post-polymerization chemical modification reactions such as hydroboration and oxidation were carried out on the extremely low molecular weight PB1,2 in all three terpolymer samples. To justify the successful incorporation of –OH groups in the polydiene segments and the preparation of polymeric brushes, various molecular, thermal, and surface analysis measurements were carried out. The synthesis and chemical modification reactions on such triblock terpolymers are performed for the first time to the best of our knowledge and constitute a promising route to design polymers for nanotechnology applications.

This review article aims to cover the most recent advances regarding the synthesis of linear ABC-type triblock terpolymers and star-shaped polymers by RAFT polymerization, as well as their self-assembly properties in aqueous solutions. RAFT polymerization has received extensive attention, as it is a versatile technique, compatible with a great variety of functional monomers and reaction conditions, while providing exceptional and precise control over the final structure, with well-defined side-groups and post-polymerization engineering potential. Linear triblock terpolymers synthesis can lead to very interesting novel ideas, since there are countless combinations of stimuli/non-stimuli and hydrophilic/hydrophobic monomers that someone can use. One of their most interesting features is their ubiquitous ability to self-assemble in different nanostructures depending on their degree of polymerization (DP), block composition, solubilization protocol, internal and external stimuli. On the other hand, star-shaped polymers exhibit a more stable nanostructure, with a distinct crosslinked core and arm blocks that can also incorporate stimuli-responsive blocks for “smart” applications.

In this work, we investigated the incorporation of a fluorescent side group, fluorescein octyl ester (FOE), in benzodithiophene-based donor-acceptor terpolymers as a strategy to modulate excited-state behavior. Three FOE-containing terpolymers ( ), obtained at different polymerization times, were systematically evaluated against an analogous material without the fluorescent pendant unit ( ). Thermal analysis revealed good thermal stability and an increase in glass transition temperature upon FOE incorporation, suggesting restricted segmental mobility and increased conformational constraints within the conjugated backbone. Optical characterization showed distinct absorption spectra with reaction time and shorter fluorescence lifetimes for the FOE-containing materials, consistent with the presence of additional excited-state deactivation pathways and intramolecular energy transfer processes within the terpolymer backbone. An approximate estimation of energy transfer efficiencies (≈60-65%) suggested that such processes may be operative within the system. Cyclic voltammetry measurements showed only minor variations in HOMO and LUMO energy levels between and series, indicating that the conjugated backbone predominantly determined the frontier orbital energies despite side chain modification. Furthermore, photocurrent measurements from the bilayer device configuration exhibited a systematic increase in photocurrent for the FOE-containing material, supporting the role of excitonic modulation, rather than significant changes in interfacial energetic alignment. These results suggest that fluorescent side chain incorporation provides an effective strategy for regulating exciton dynamics while maintaining the electronic structure of the donor-acceptor terpolymer.