CCS Chemistry最新文献

The fabrication of liquid-free ionic conductive elastomers (ICEs) that can function as flexible temperature sensors with high sensitivity, fast response time, and efficient recyclability is a great challenge. In this study, novel liquid-free ICEs are conveniently fabricated through the complexation of 4-carboxybenzaldehyde-grafted poly(vinyl alcohol) (CPVA) with well-designed solid quaternary ammonium (QA) molecules bearing bifunctional hydrogen-bonding moieties. The resulting CPVA-QA elastomers, which are highly elastic and adhesive to diverse surfaces, exhibit a tensile strength of 6.6 MPa, a toughness of 14.7 MJ m⁻³, and a Young’s modulus of 0.15 MPa. These elastomers have a hydrogen-bonded network structure where the bifunctional QA molecules significantly suppress polymer chain entanglements. Benefitting from the thermally sensitive hydrogen bonds and the substantially reduced chain entanglements, the CPVA-QA elastomers show a high chain mobility upon temperature elevation, which facilitates ion transport within the CPVA-QA elastomers. Consequently, the CPVA-QA elastomer-based temperature sensors show an outstanding temperature resolution (0.05 °C), a fast response time over a wide temperature range, and a record-high thermosensitivity of 10.8% K⁻¹. Importantly, the CPVA-QA sensors can be depolymerized under mild conditions to recover their original components in high purity and yields (>96%), enabling closed-loop recycling of the sensors.

For studies concerning circularly polarized multiple resonances thermally activated delayed fluorescence (CP-MR-TADF) emitters with central chirality, only carbon element has been applied. Herein, for the first time, we report a CP-MR-TADF material with phosphorus central chirality containing tert-butyl(phenyl)phosphine oxide, (R/S)-4-POtBuCzB, as enantiomers exhibiting the narrowest full-width at half-maximum (FWHM = 20 nm) among the reported CP-TADF molecules, with symmetric CP photoluminescence and a dissymmetry factor (|g_PL|) of 0.54 × 10⁻³. Concurrently, 2-POtBuCzB further demonstrated that phosphine participated in photophysical performance regulation. Notably, CP organic light-emitting diodes (CP-OLEDs) using (R/S)-4-POtBuCzB showed remarkable CPEL activity with a |g_EL| of 0.61 × 10⁻³, and OLED with 2-POtBuCzB, achieving a maximum external quantum efficiency (EQE_max) of 37.0%. These results demonstrate that introducing chiral phosphorus fragments into the MR-TADF skeleton is an efficacious approach for CP-MR-TADF materials and devices.

In this work, we report a facile and efficient supramolecular strategy for the construction of color-tunable thermally activated delayed fluorescence polymeric materials (TADF PMs) through host–guest complexation. Consequently, new kinds of TADF PMs exhibiting multicolor emissions were constructed conveniently by mixing a calix[3]acridan-modified polymer and various commercially available receptors. This emergent TADF property was attributed to the formation of the through-space charge transfer (TSCT) interactions between the macrocyclic donor in the polymer and the guest acceptors. Moreover, multicolor emission and high photoluminescence quantum yield (PLQY) of up to 40% were achieved readily by tailoring the guests with different electron-withdrawing abilities. Further, we found that the TADF PMs could be prepared readily on a large scale with good processability; thus, the approach could achieve potential application on rewritable advanced information encryption. Therefore, this work not only develops an efficient supramolecular strategy to design and construct color-tunable TADF PMs but also offers a new perspective for their practical applications in materials science.

Microbial cultivation in microcompartments using water-in-oil (w/o) emulsion droplets has greatly advanced the study of strict anaerobic bacteria. However, a major challenge lies in the separation and recovery of the bacterial liquid. In this study, we address this challenge by localizing strict anaerobes within w/o Pickering emulsion droplets stabilized by modified microgel particles. This approach demonstrates remarkable efficiency in bacterial microencapsulation, growth and separation. The microgel particles are modified in-situ with hydrophobic silica allowing for stabilization of w/o emulsions at the optimum cultivation temperature of 37 °C while the continuous oil phase prevents oxygen ingress thereby maximizing anaerobic fermentation. Additionally, a temperature decrease triggers the microgel particles to swell and become hydrophilic, causing an immediate inversion of the emulsion to oil-in-water type. This facilitates complete separation and collection of the bacterial suspension without any damage or loss. The intelligent phase inversion of the emulsion presents exciting possibilities for various applications in anaerobic fermentation, synthetic biology and biomanufacturing.

The availability of high-quality and durable bifunctional oxygen electrode catalysts remains a significant linchpin for rechargeable zinc-air batteries (ZABs). Modulating the d/f orbitals of isolated single-atom metal sites to enhance the reaction kinetics is an eloquent strategy. Herein, we fabricate a single-atom rhenium catalyst (Re-NG) with Re-N₄ sites on N-doped graphene, which renders exceptional oxygen reduction reaction (ORR) catalytic capacity, delivering a half-wave potential of 0.86 V and excellent oxygen evolution reaction (OER) activity with low overpotential (η₁₀ = 368 mV). Furthermore, the Re-NG performs satisfactorily on the cathode of a rechargeable ZAB with cell voltages as high as 1.53 V and specific capacities as high as 828.7 mA h g_Zn⁻¹, which is close to theoretical value, and outstanding cycling stability. The excellent performance of the Re-NG can be attributed to the structural evolution at different reaction potentials as revealed by in situ X-ray absorption spectrum characterization and theoretical simulations, resulting in the formation of different active sites (ReN₄-O/Re-N₄-2O), which effectively and stably catalyze the reactions, thus accelerating the ORR/OER kinetics and enabling high activity. Our study clearly elucidates the mechanisms by which Re-NGs efficiently catalyze oxygen electrode reactions, providing a valuable reference for the as yet unknown catalytic mechanism of single-atom oxygen catalysts.

Decrypting information from polymer chains is crucial in investigating molecular data storage media. However, decoding structural information about polymers at the single-chain level remains a significant challenge. Here, we design and construct tetraphenylethylene-based metallopolymers through covalent polymerization followed by intramolecular coordination. The tetratopic monomer as a mixture of Z/E-isomers contains two terminal alkynyl groups for polymerization and two 2,2′:6′,2′′-terpyridine moieties for coordination with Zn(II) or Fe(II) ions. Through incorporating coordination junctions into the polymer backbone, we are able to directly visualize individual metallopolymer chains using scanning tunneling microscopy and obtain multidimensional structural details of metallopolymers, including polymerization degree, Z/E configuration ratio, and the exact configuration sequence of a single polymer. Furthermore, we deduce the relationship between the conformation and corresponding persistence length of metallopolymer chains based on the distribution of bright lobes of coordination junctions in each polymer chain. As such, this study offers an alternative approach to obtaining multidimensional structural information at the single-chain level.