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Carbon materials doped with heteroatoms are considered as an optimal substitute for commercial Pt/C (JM-Pt/C) catalysts in oxygen reduction reactions (ORRs) owing to their cost-effectiveness and elevated efficacy. This paper reported a facile single-step approach for the synthesis of N/P-codoped carbon nanotubes (N/P-CNTs) using diammonium dihydrogen phosphate and 2-methylimidazole as precursors and carbon nanotubes (CNTs) as matrix materials. N/P-CNT-900 exhibited exceptional catalytic activity for ORR in alkaline environments with half-wave potential (E1/2) of 0.83 V and showed commendable methanol tolerance and stability. In addition, the catalysts were used to construct a Zn–air battery (ZAB), and its open circuit voltage (OCV) and peak power density (1.56 V, 193.22 mW cm–2) surpassed the performance of JM-Pt/C catalysts (1.50 V, 96.04 mW cm–2), indicating their great advantage for extensive-scale utilization in electrochemical energy conversion devices. This work provided ideas for the development and optimization of metal-free ORR catalysts. [ABSTRACT FROM AUTHOR]

Magnetorheological fluids (MRFs) are promising smart materials that can respond to an external field. In order to obtain stable suspension and investigate the settlement law of these synthesised MRFs, polymerised ionic liquid crystalline (PILC) ferroferric oxide nanocomposites (Fe3O4@PILCs), the dispersed phase in MRFs, were obtained by self-assembly of magnetic Fe3O4 nanoparticles with PILCs. The structural properties, thermotropic liquid crystal characteristics, morphology and microscopic magnetic response characteristics were investigated in this study. Fe3O4@PILCs showed nematic liquid crystal behaviour, and the mesogenic phase range was affected by the content of cholesteryl-based LC mesogen containing carboxylic acid groups. Series of MRFs were prepared by the Fe3O4@PILCs with 5% particles mass fractions in different volume fractions. The settlement stability as well as the settlement laws was investigated comprehensively and systematically for these MRFs. The Fe3O4@PILC-based MRFs exhibited better sedimentation stability than the bare Fe3O4-based MRFs, indicating that the Fe3O4 particles self-assembled with PILCs could reduce the density of the dispersed phase and showed the good compatibility with silicone oil carrier fluid. The sedimentation velocity curves of the Fe3O4@PILC-based with different particle volume fractions were investigated by use of some relevant theoretical models, indicating that they were the most consistent with the Dick's model. [ABSTRACT FROM AUTHOR]

Series of poly(styrene sulphonic acid)-based graphene oxide liquid crystals (GOLCs) were synthesised by use of graphene oxide (GO), poly(styrene sulphonic acid), cholesteryl-containing liquid crystal and pyridinyl-based compounds in a self-assembly process. The chemical structure, liquid crystalline behaviour and antistatic property were investigated using appropriate analytical instrument and various experimental techniques. The GOLCs exhibited smectic A phase on heating cycles. The antistatic property was performed by use of a four-probe measuring instrument at different humidity conditions after a liquid crystalline ordering structure were well developed in these GOLC films. All the GOLC films show surface resistivity on the same order of magnitude (kΩ sq−1) at different relative humidity, suggesting that the humidity of the environment is not dominant in the antistatic property. In the microstructure, the GOLC layers are aligned in a liquid-crystalline ordering structure, a hydrogen bonding area of the sulphonic acid- and carboxylic acid-pyridyl linkages around GO is formed continuously without interruption, leading to conduction pathways from the interior cores to the whole surface. It indicates that antistatic property of these GOLCs is not completely dependent on the surface humidity derived from water absorption. [ABSTRACT FROM AUTHOR]

A series of novel star-shaped ionic liquid crystals (ILCs) compounds with various counterions (derived from HBF4, HPF6, CF3COOH, d-MH-SO3H, H3PO4, p-Toluenesulfonic acid) were designed and synthesised starting from precursors of pyridines and liquid crystalline monomer cholesteryl 4-bromobutanoate. Inducing various counterions by use of ionic self-assembly due to electrostatic attraction of various ion clusters was one of the most essential factors for intermolecular separation. The chemical structures, liquid crystalline properties, self-assembly behaviour and ionic conductivity of these compounds were researched during multiple experimental techniques. The star-shaped ILCs showed a smectic A (SmA) mesophase. The d-spacing of star-shaped ILCs increased slightly due to the increase volume of anion. The clearing temperatures of the pyridinium salts suggested that the effect of the stabilisation on the SmA structures was in the order H2PO4−>BF4−>TS−>D-MH-SO3−>CF3COO−>PF6−. All these star-shaped ILCs displayed ionic conductivity in mesophase. It was noted that the conductivity (σ) increased with the increase of the anion size and temperature. [ABSTRACT FROM AUTHOR]

Self‐assembly of mesogens in one polymer system reflects the capability for integrating intermolecular interactions and functions of materials. A series of novel supramolecular complexes (SCPs) containing cholesterol derivatives, siloxane backbone and copper phthalocyanine were synthesized. The SCPs were made from sulfonic acid‐containing precursor polymers (SAPs) synthesized by the use of 4‐(allyloxy)benzenesulfonic acid, cholest‐5‐en‐3‐ol‐(3β)‐4‐(allyloxy)benzoate and polymethylhydrosiloxane. Differential scanning calorimetry, polarizing optical microscopy and X‐ray diffraction results confirmed the mesomorphic properties. The SAPs showed smectic phase, but the SCPs showed columnar phase due to more lateral copper phthalocyanine groups in the polymer systems. Moreover, because of rigid side groups and cholesteric polymer, SCPs showed greater d‐spacings between the side mesogenic groups and exhibited very good electrical conductivity. © 2018 Society of Chemical Industry Supramolecular complexes containing cholesterol derivatives, siloxane backbone and copper phthalocyanine were synthesized, whereby the liquid crystal phase changes from smA to Colh. The complexes exhibit good electrical conductivity. [ABSTRACT FROM AUTHOR]