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To achieve superior performance of electrode materials, the design of rational and advantageous hierarchical structures has been confirmed as an effective and feasible approach. Herein, we report an effective strategy for the synthesis of hierarchical NiSe2 spheres composed of nanoparticles: Ni(OH)2 flowers were firstly prepared as the precursor via a solvothermal method followed by a solvothermal selenylation reaction to prepare hierarchical NiSe2 spheres. Investigated as electrode materials for asymmetric supercapacitors, the NiSe2 spheres//AC device exhibits enhanced electrochemical performance with a high specific capacitance of 99.7 F g−1 at a current density of 2 A g−1. In addition, high energy/power density and long-term cycling stability over 10 000 cycles have been shown, which derive from the nanosized building-blocks and secondary micro-architecture. [ABSTRACT FROM AUTHOR]

In this work, self-healing chiral photonic films (SCPFs) fabricated by the co-assembly of cellulose nanocrystals (CNCs) with a boronic ester crosslinked poly(vinyl alcohol)–polyacrylamide hydrogel is described. The reversible covalent bonds of boronic esters enable the self-healing of SCPFs, the convenient formation of patterns/stacked structures, and the incorporation of SCPFs onto rough and porous surfaces, addressing a universal method for constructing photonic structures on various substrates. The double layer structures of SCPFs with bulk hydrogels enable multidimensional sensing via dynamic reflectance spectroscopy. The unique dynamic reflectance spectral patterns, as well as regular changes in reflectance maxima and delay time, demonstrate a sensitive photonic sensor. As a result of the self-healing properties, the robust anti-counterfeiting layers formed by the SCPFs on paper-printed QR codes realize polarization-dependent recognitions by a smartphone. The approach allows the incorporation of chiral photonic crystals onto various substrates with high optical quality, providing flexibility to design chiral photonic structures for sensing and security applications. [ABSTRACT FROM AUTHOR]

An imine-based 2D polymer side-functionalized with o-hydroxyl group was designed in regard to its potential ability to serve as a chelating agent and synthesized on a highly oriented pyrolytic graphite surface with a relatively low annealing temperature. When annealed to a higher temperature the o-hydroxyl group reacts further with the imine group, leading to the formation of oxazoline, which causes significant distortion to the network. The formation of oxazoline was further confirmed by ATR-FTIR. [ABSTRACT FROM AUTHOR]

In this work we provide a systematic scanning tunneling microscopy (STM) study on the self-assembling and mixing behavior of Arylene Ethynylene Macrocycles (AEMs) containing 1,4-phenylene, 1,4-naphthylene or 9,10-anthrylene substituents at the solid/liquid interface. The effect of bulky substituents on the self-assembly structure was investigated and we found that 1,4-phenylene ethynylene macrocycle (AEM-B) and 1,4-naphthylene ethynylene macrocycle (AEM-N) form four and three different patterns at the 1,2,4-trichloride benzene (TCB)/graphite interface, respectively, and a significant concentration effect was observed for both molecules. 9,10-anthrylene ethynylene macrocycle (AEM-A) only forms a filled honeycomb structure at relatively high concentrations. The effect of bulky substituents was attributed to the steric hindrance, which hinders full interdigitation of alkoxy chains. The mixing behavior of binary mixtures of arylene ethynylene macrocycles was also investigated at the TCB/HOPG interface. The results demonstrate that the steric hindrance brought by the bulky groups does not enable sufficient recognition between identical molecules at the interface and random mixing was observed for binary mixtures of AEM-B and AEM-N. The mixing behavior of AEMs could also be predicted by the parameter called the 2D isomorphism coefficient. [ABSTRACT FROM AUTHOR]

A highly efficient recognition phenomenon was observed between alkoxylated arylene-ethynylene macrocycles bearing identical side chains but different core size, which is based on van der Waals interactions between alkoxy chains. The ratio of both molecules and the environment of each molecule have been statistically analyzed to quantify the recognition efficiency.