Search

Pseudo‐nanophase separation enabled by supramolecular‐interaction‐grafted sidechains proves a promising alternative for constructing high‐performance commercially viable membranes with quick ion transport, excellent chemical stability, and simplified membrane manufacturing. Nonetheless, the concept of pseudo‐nanophase separation is still in nuce, and determinants for controlling pseudo‐nanophase separation remain somewhat opaque. In this contribution, supramolecular sidechain topology is found critical to engineering pseudo‐nanophase separation. Three supramolecular sidechain topological (viz. linear, branched, and cyclic) structures are investigated using experimental and theoretical protocols, and the underlying mechanisms by which supramolecular sidechain topology alters the microstructure and ion‐conducting behaviors of the membranes are proposed. Consequently, the cyclic sidechain‐mediated membrane achieves the highest proton conductivity with an area resistance as low as 0.10 Ω cm2. The resulting membrane endows an acidic aqueous redox flow battery with an energy efficiency of up to 80.7% even at high current densities of 220 mA cm−2, breaking the record set by the pseudo‐nanophase separation strategy constructed membranes and ranking among the highest values ever documented. This study advances the understanding of supramolecular sidechain topology for the design and preparation of high‐performance membranes via pseudo‐nanophase separation engineering for flow batteries and beyond. [ABSTRACT FROM AUTHOR]

Pseudo-nanophase separation, enabled by noncovalently grafted sidechains, offers a promising approach for constructing high-performance membranes, featuring rapid ion transport, robust chemical stability, and simplified manufacturing. However, striking a balance between ionic conductivity and mechanical/chemical stability proves challenging since excessive hydrophilic grafting leads to overswelling and compromised integrity of the membranes, rendering them unsuitable for demanding applications like vanadium redox flow batteries (VRFBs). In this study, we describe a new approach for achieving high-performance VRFB membranes via employing polymer as supramolecular sidechains, rather than small molecules. This strategy achieves remarkable pseudo-nanophase separation while minimizing the utilization of functional (hydrophilic) sites. As a result, the resulting membranes exhibit exceptional robustness and proton conductivity, with an extraordinarily low area resistance of merely 0.11 Ω cm2, thus circumventing the prevailing trade-off between ionic conductivity and mechanical/chemical stability. Ultimately, VRFBs integrated with these membranes achieve energy efficiencies up to 80 % even at high current densities of 240 mA cm−2, accompanied by a remarkably low capacity decay rate of 0.064 % per cycle during long-cycle tests. This work not only achieves ultra-high conductivity with minimal functional groups, but also advances pseudo-nanophase separation strategies and provides valuable insights into optimized utilization of limited functional groups in membrane design. [Display omitted] • Polymers are proposed as supramolecular sidechains. • Underlying interaction mechanism is elucidated by experimental and simulation study. • A minimal number of hydrophilic sites enable noteworthy pseudo-nanophase separation. • Prevailing conductivity-mechanical/chemical stability trade-off is circumvented. • A VRFB with high efficiencies and slow capacity decay of 0.064 %/cycle is attained. [ABSTRACT FROM AUTHOR]

Mercury is a highly toxic heavy metal and it poses a serious threat to the natural environment and human health. Thus, selective detection of trace mercury ( e.g. inorganic mercury and methylmercury) in the environment is critical yet challenging. Herein, we describe the rational design and facile synthesis of a new triphenylamine-based phenylboronic acid fluorescent probe (TPA-PBA) for selective detection of Hg 2+ and CH 3 Hg + . Due to the inherent specificity of the displacement reaction between phenylboronic acid and mercury, this probe exhibits exceptionally high selectivity towards Hg 2+ /CH 3 Hg + against other tested ions with ppb-level sensitivity. More importantly, the probe TPA-PBA is effective and selective in detecting Hg 2+ /CH 3 Hg + in tap water and real-world groundwater, indicating its potential practical applications in in situ and online mercury detection in real-world scenarios. With TPA-PBA based test strips Hg 2+ can be distinguished from CH 3 Hg + by the naked eye. This study could accelerate the development of low-cost, highly efficient and selective fluorescent probes for rapid trace mercury detection.

Crystalline supramolecular architectures mediated by cations, anions, ion pairs or neutral guest species are well established. However, the robust crystallization of a well-designed receptor mediated by labile anionic solvate clusters remains unexplored. Herein, we describe the synthesis and crystalline behaviors of a trimacrocyclic hexasubstituted benzene 2 in the presence of guanidium halide salts and chloroform. Halide hexasolvate clusters, viz. [Cl(CHCl 3 ) 6 ] - , [Br(CHCl 3 ) 6 ] - , and [I(CHCl 3 ) 6 ] - , were found to be critical to the crystallization process, as suggested by the single-crystal structures, X-ray powder diffraction (XRPD), thermogravimetric analysis (TGA), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), and NMR spectroscopy. This study demonstrates the hitherto unexpected role that labile ionic solvate clusters can play in stabilizing supramolecular architectures., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)