- High-Performance Double-Network Ion Gels with Fast Thermal Healing Capability via Dynamic Covalent Bonds
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A tough double-network (DN) ion gel composed of chemically cross-linked poly(furfuryl methacrylate-co-methyl methacrylate) (P(FMA-co-MMA)) and physically cross-linked poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-co-HFP)) networks with 80 wt % of ionic liquid (IL) was fabricated via a one-pot method. This ion gel exhibits excellent mechanical strength and considerable ionic conductivity, which can be used as a solid gel electrolyte. Upon an adjustment of the weight ratio of P(FMA-co-MMA) to P(VDF-co-HFP) and the content of the cross-linker, remarkably robust DN ion gel (failure tensile stress 660 kPa, strain 268%; failure compressive stress 17 MPa, strain 85%) was obtained. The high mechanical strength is attributed to the chemical/physical interpenetrating networks. The rigid chemically cross-linked P(FMA-co-MMA) network dissipates most of the loading energy, and the ductile physically cross-linked P(VDF-co-HFP) network provides stretchability for the whole gel. More importantly, the P(FMA-co-MMA) network is formed by dynamic covalent bonds that can undergo a thermally reversible reaction, giving the gel a unique and effective thermal healing capability. Furthermore, with the high content of IL, the DN ion gel possesses a high ionic conductivity of 3.3 mS cm-1 at room temperature, which is higher than those of most solid polymer electrolytes and comparable to those of commercial organic liquid electrolytes.
- Tang, Zhehao,Lyu, Xiaolin,Xiao, Anqi,Shen, Zhihao,Fan, Xinghe
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- Diels–Alder Polymer Networks with Temperature-Reversible Cross-Linking-Induced Emission
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A novel synthetic strategy gives reversible cross-linked polymeric materials with tunable fluorescence properties. Dimaleimide-substituted tetraphenylethene (TPE-2MI), which is non-emissive owing to the photo-induced electron transfer (PET) between maleimide (MI) and tetraphenylethene (TPE) groups, was used to cross-link random copolymers of methyl (MM), decyl (DM) or lauryl (LM) methacrylate with furfuryl methacrylate (FM). The mixture of copolymer and TPE-2MI in DMF showed reversible fluorescence with “on/off” behavior depending on the Diels–Alder (DA)/retro-DA process, which is easily adjusted by temperature. At high temperatures, the retro-DA reaction is dominant, and the fluorescence is quenched by the photo-induced electron transfer (PET) mechanism. In contrast, at low temperatures, the emission recovers as the DA reaction takes over. A transparent PMFM/TPE-2MI polymer film was prepared which shows an accurate response to the external temperature and exhibited tunable fluorescent “turn on/off” behavior. These results suggest the possible application in areas including information security and transmission. An example of invisible/visible writing is given.
- Hadjichristidis, Nikos,Jiang, Yu
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- Purification of furfuryl methacrylate (by machine translation)
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[A] a method of manufacturing cost and safety furfuryl methacrylate · · easily. [Solution] the furfuryl, methacrylic acid ester as a starting material in the transesterification reaction, transesterification catalyst and electron-deficient olefin compounds are employed, and by the use of a distillation column, the reaction byproduct can be removed by reaction of the alcohol is effective to promote, the impurities can be efficiently removed by distillation, characterized in that the simple method for producing high-purity furfuryl methacrylate. Figure 1 [drawing] (by machine translation)
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Paragraph 0122
(2017/08/02)
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