Environment-Interactive Programmable Deformation of Electronically Innervated Synergistic Fluorescence-Color/Shape Changeable Hydrogel Actuators.

Utilization of life-like hydrogels to replicate synergistic shape/color changeable behaviors of living organisms has been long envisaged to produce robust functional integrated soft actuators/robots. However, it remains challenging to construct such hydrogel systems with integrated functionality of remote, localized and environment-interactive control over synergistic discoloration/actuation. Herein, inspired by the evolution-optimized bioelectricity stimulus and multilayer structure of natural reptile skins, electronically innervated fluorescence-color switchable hydrogel actuating systems with bio-inspired multilayer structure comprising of responsive fluorescent hydrogel sheet and conductive Graphene/PDMS film with electrothermal effect is presented. Such rational structure enables remote control over synergistic fluorescence-color and shape changes of the systems via the cascading "electrical trigger-Joule heat generation-hydrogel shrinkage" mechanism. Consequently, local/sequential control of discoloration/actuation are achieved due to the highly controllable electrical stimulus in terms of amplitude and circuit design. Furthermore, by joint use with acoustic sensors, soft chameleon robots with unprecedented environment-interactive adaptation are demonstrated, which can intelligently sense environment signals to adjust their color/shape-changeable behaviors. This work opens previously unidentified avenues for functional integrated soft actuators/robots and will inspire life-like intelligent systems for versatile uses.

One-step fabrication of dual functional Tb3+ coordinated polymeric micro/nano-structures for Cr(VI) adsorption and detection.

Hexavalent chromium Cr(VI) has been considered as one of the most hazardous heavy metals because of its strong and persistent toxicity to the ecosystem and human beings. Herein, we have synthesized a double hydrophilic block co-polyarylene ether nitriles (abbreviated as dhPEN) bearing aromatic backbone as well as pendent carboxyl and sulfonate groups. Afterward, the synthesized dhPEN has been co-assembled with the lanthanide Tb3+ via a one-step solvent exchange protocol, leading to generation of Tb3+ coordinated dhPEN (Tb-dhPEN) micro/nano-structures that exhibit good adsorption capacity and detection sensitivity towards Cr(VI). More specifically, the direct self-assembly of dhPEN and Tb3+ in mixed H2O/DMF solvents resulted to Tb-dhPEN microparticles with lamellar structures, which exhibited a high Cr(VI) adsorption capacity approaching to 402 mg/g. The detailed characterization confirm that Cr(VI) is adsorbed and partially reduced to Cr(III) by the Tb-dhPEN microparticles via chemical interaction. Furthermore, the self-assembly of dhPEN with Tb3+ in the H2O/DMF mixed solvents containing NaOH contributed to the generation of spherical nanoparticles showing green emission at 545 nm, which can be selectively quenched by the Cr(VI), leading to the specific detection of trace concentration of Cr(VI) down to 0.12 nM as well as reliable determination of Cr(VI) presented in real environmental samples.

Fluorinated Oligomer Wrapped Perovskite Crystals for Inverted MAPbI3 Solar Cells with 21% Efficiency and Enhanced Stability.

Defects at the grain boundary provide sites for nonradiative recombination in halide perovskite solar cells (PSCs). Here, by polymerization and fluorination of a Lewis acid of 4,4-bis(4-hydroxyphenyl)pentanoic acid, a fluorinated oligomer (FO-19) is synthesized and applied to passivate these defects in methlyammonium lead iodide (MAPbI3). It is demonstrated that the carboxyl bond of FO-19 was coordinated with Pb ions in the perovskite films to achieve a wrapping effect on the perovskite crystals. The defects of perovskite film are effectively passivated, and the undesirable nonradiative recombination is greatly inhibited. As a result, FO-19 gives a power conversion efficiency of 21.23% for the inverted MAPbI3-based PSCs, which is among the highest reported values in the literature. Meanwhile, the corresponding device with FO-19 exhibits significantly improved humidity and thermal stability. Therefore, this work offers insights into the realization of high-efficiency and stable PSCs through fluorinated additive engineering.

Scalable Fabrication of Metallopolymeric Superstructures for Highly Efficient Removal of Methylene Blue.

Metallopolymeric superstructures (MPS) are hybrid functional materials that find wide applications in environmental, energy, catalytic and biomedical-related scenarios, while their fabrication usually suffers from the complicated polymerization between monomeric ligands and metal ions. In this work, we have developed a facile one-step protocol to fabricate metallopolymeric superstructures with different morphology including nanospheres, nanocubes, nanorods, and nanostars for environmental remediation application. Specifically, we have firstly synthesized the amphiphilic block copolymers (BCP) bearing hydrophobic aromatic backbone and hydrophilic pendent carboxylic/sulfonic groups, which have been subsequently transformed into MPS via the metal ions mediated self-assembly in mixed solution of dimethylformamide (DMF) and H2O. Based on SEM, FTIR, XRD and XPS characterization, we have revealed that the fine morphology and condensed structures of MPS can be modulated via the metal ions and BCP concentration, and the obtained MPS can be employed as efficient adsorbents for the removal of methylene blue with maximum adsorption capacity approaching 936.13 mg/g.