Extensive attention has been received in recent years for perovskite-polymer composites because of their combination of properties from polymers and perovskites. In this work, a convenient and universal strategy is reported to prepare cesium lead bromide or organolead halide methylammonium bromide polymer composites. This technique integrates the formation of perovskite crystals and the polymer matrix in a one-pot reaction, avoiding the tedious separation and preparation of perovskites. The method is universal for most of the commercially available monomers and polymers, which has been verified in this report using poly(methyl methacrylate), poly(butyl methacrylate), and polystyrene. The physical properties of the varied polymers lead to different luminescent properties and stabilities of the composites. No organic solvent is required during the preparation, indicating a green technique for the composites. Additionally, the resulted perovskite-polymer composites are extraordinarily stable, maintaining their quantum yield for more than 1 month in air. On the basis of the above properties, a prototype of white light-emitting diodes was successfully constructed with feasible color characters and narrow bandwidths. Furthermore, large-area (dimension: 10 × 7 × 0.15 cm) perovskite-polymer plates are easily prepared via the one-pot strategy, showing that the technique is ready for possible large-area optical devices. This work provides an efficient technique toward various kinds of perovskite-polymer composites for both scientific research studies and future applications.
Liquid metals (LMs) are receiving growing interest in modern technologies for their various advantages. This work reports using elemental sulfur to achieve nanodispersed liquid metals in bulk polymers for multifunctional LM-based materials. Ring-opening polymerization and inverse vulcanization of elemental sulfur provide many polysulfide loops and thiol groups as effective binding ligands that enable extraordinarily uniform dispersion of liquid metals (≈1 µm) in bulk matrix and improve the mechanical performance of the materials. Interestingly, the liquid-metal-embedded sulfur polymer (LMESP) materials exhibit excellent thermal-/solventprocessability and recyclability. The uniform dispersion leads to phenomenal electrical conductivity of the LMESP at a low volume percentage of LM (30 vol%), overcoming the issue of nonconductivity typically seen in insulated LM-polymer blends. Additionally, the LMESP shows resistive sensitivity toward external pressure. Furthermore, the LMESP materials exhibit an excellent self-healing ability under mild conditions via the dynamic bonds between polysulfide loops/thiol groups and liquid metals. This work clearly offers a new platform to design liquid metals and can push them for broad applications.
Liquid metals (LMs) are used as liquid fillers in hydrophilic polymer networks to realize ultra-stretchable hydrogels as asymmetric force-sensors. The existence of liquid metals endows the hydrogel with unique features in synthetic methods and sensing applications.
Liquid metal (LM) is used as fillers gradient dispersed in polymer matrix to prepared LM fiber. Such LM fiber showed distinguished thermally programmable shapes and electrical conductivities.
Metal–polymer composites (MPCs) with combined properties of metals and polymers have achieved much industrial success. However, metals in MPCs are thought to be ordinary and invariable electrically conductive fillers in supportive polymers to show limited use in modern technologies. This work that is disclosed here, for the first time, introduces stimuli‐driven transition from biphasic to monophasic state of liquid metal into polymer science to form dynamic soft conductors from the binary metal–polymer composites. The binary metal that exhibits temperature‐driven reversible transition between solid and liquid states via a biphasic state is fabricated. A conducting stretchable polymer composite is developed using the judiciously chosen biphasic binary metal that undergoes conductor to insulator transition upon stretching. Insulating stretched films become conducting upon heating. A “tube” model elegantly describes such distinctive deformation/temperature‐dependent behaviors. Moreover, the conducting polymer composite shows decrease in its resistance upon increasing the sample temperature. The resistance can be tuned from 1 to 108 Ω depending on the state of binary metal in the phase diagram. This work would build the intimate and interesting connection between metal phases and polymer science toward next‐generation soft conductors and beyond.
Emissive cross-linkers are of special interest for polymer science because of their ability to endow polymer networks with luminescent properties. Methylammonium lead halide perovskite nanoparticles (MAPbCl Br NPs) are extensively explored for optical and optoelectronic applications. In this work, MAPbCl Br NPs with cross-linkable and polymerizable ligands are successfully prepared as new emissive cross-linkers for polymer networks. Commercially available reagent 2-aminoethyl methacrylate hydrochloride (AMHCl) can act as a ligand to stabilize MAPbBr NPs in solution. Compared with traditional ligands (oleic acid and oleylamine), AMHCl retains the architecture of perovskite effectively and affords polymerizable groups (vinyl) on the surface of perovskites. The as-prepared MAPbCl Br NPs can serve as cross-linkers in the radical polymerization of (meth)acrylates by UV-light to form polymer networks. Meanwhile, such cross-linkable emitters exhibit bright luminescence and color-tunability at room temperature, attributed by a unique halide exchange of perovskites between CHNHBr and AMHCl, which provides the polymer networks with varied emissive bands. These perovskite-crosslinked networks showed high air stability, water stability, and prominent photoluminescence quantum yields. On the basis of these excellent properties, white-light-emitting diodes were successfully fabricated from these perovskite-crosslinked composites with color-coordinate values at (0.316, 0.315), very close to the standard coordinates of white light. This work elucidates a new and convenient technique to convert nanocrystals into luminescent cross-linkers to build functional polymeric networks for technological applications.
We reported for the first time using metal–organic framework (MOF) nanoparticles as effective nanofillers to significantly enhance the mechanical performance of hydrogels. The MOF hydrogels have been developed for drug delivery materials with high loading capacity and much extended drug releasing profiles.
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