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Poly(N-(3-carboxyphenyl)maleimide-alt-styrene) with superior heat-resistance was synthesized by free radical copolymerization and its structure was confirmed by FTIR and NMR spectroscopy. To show the advantages in heat-resistance of the synthesized copolymers, the thermal properties of poly(N-phenylmaleimide-alt-styrene) and poly(N-phenylmaleimide-alt-maleic anhydride) with similar structures were determined. DSC/TG analysis showed that the synthesized copolymer exhibited the better thermal properties than two other copolymers due to the formation of a chemically crosslinked three-dimensional network during heating.

Lithium–sulfur (Li–S) batteries are considered as one of the most promising candidates for next-generation energy storage systems with high energy density and reliable performance. However, the commercial applications of lithium–sulfur batteries is hindered by several shortcomings like the poor conductivity of sulfur and its reaction products, and the loss of active materials owing to the diffusion of lithium polysulfides (LiPSs) into the electrolyte. Hence, the effective restraining of the LiPSs and the promotion of the sluggish conversion are highly demanded to fulfill the potential of lithium–sulfur batteries. Here, we summarize the applications of transition-metal sulfides (TMSs) in the cathodes over recent years and demonstrate the unique advantages they possess to realize reliable long-life lithium–sulfur batteries.

Introducing the chiral spacers to two-dimensional (2D) lead halide perovskites (LHPs) enables them to exhibit circularly polarized photoluminescence (CPPL), which could have applications in chiral-optics and spintronics. Despite that a great deal of effort has been made in this field, the reported polarization degree of CPPL at ambient conditions is still very limited, and the integration of multiple functionalities also remains to be explored. Here we report the structures, CPPL, and piezoelectric energy harvesting properties of chiral 2D LHPs, [

The poly(l-lactide-b-ethylene glycol-b-l-lactide) (PLLA-PEG-PLLA) triblock copolymers with different chain segment length are fabricated by ring-opening polymerization. The structure, molecular weight, and crystallization behaviors of the triblock copolymers are characterized by Fourier transform infrared, nuclear magnetic resonance spectroscopy, gel permeation in chromatography, X-ray diffraction, differential scanning calorimetry, and polarizing optical microscopy (POM). The results show that the increase of block length is beneficial to improve its crystallization. In addition, the triblock copolymer exhibits a double crystallization phenomenon. The POM results indicate that PEG and PLLA chains of the copolymer crystallize in their respective crystallization temperature regions. The growth rate of the PLLA spherocrystal decreases and the dendritic spherocrystals appear with increasing the PEG chain length when the PLLA chain of the copolymer is isothermal crystallized at 80°C and PLLA chain length is constant. The growth rate of the PEG spherocrystal decreases and the spherocrystal morphology changes little with increasing PLLA chain length when the PEG chain is isothermal crystallized at 25°C and the length of PEG chain remained unchanged.

Hybrid organic-inorganic piezoelectrics have attracted attention due to their simple synthesis, mechanical flexibility, and designability, which have promising application potential in flexible sensing and self-powered energy harvesting devices. Although some hybrid piezoelectrics are discovered, most of their structures are limited by the perovskite-type and often contain lead. Herein, the synthesis, structure, and piezoelectric properties of a new hybrid lead-free metal halide, (BTMA)2 CoBr4 (BTMA = benzyltrimethylammonium) are reported. The experimental and theoretical results demonstrate that this material simply composed of [CoBr4 ]2- tetrahedra and BTMA+ cations exhibits significant piezoelectricity (d22 = 5.14, d25 = 12.40 pC N-1 ), low Young's and shear moduli (4.11-17.56 GPa; 1.86-7.91 GPa). Moreover, the (BTMA)2 CoBr4 /PDMS (PDMS = polydimethylsiloxane) composite thin films are fabricated and optimized. The 10% (BTMA)2 CoBr4 /PDMS-based flexible devices show attractive performance in energy harvesting with an open-circuit voltage of 19.70 V, short-circuit current of 4.24 µA, and powder density of 11.72 µW cm-2 , catching up with those of piezoelectric ceramic composites. Meanwhile, these film devices show excellent capability in accurately sensing human body motions, such as finger bending and tapping. This work demonstrates that (BTMA)2 CoBr4 and related piezoelectric lead-free halides can be promising molecular materials in modern energy and sensing applications.