Fluorophores with color-shifting characteristics have attracted enormous research interest in the quantitative application of RNA sensors. It reports here a simple synthesis, luminescent properties, and co-transcription ability of de-conjugated triphenylmethane leucomalachite green (LMG). This novel clusteroluminescence fluorophore is rapidly synthesized from malachite green (MG) in reductive transcription system containing dithiothreitol, emitting fluorescence in the UV region through space conjugation. The co-transcribed MG RNA aptamer (MGA) bound to the ligand, resulting in red fluorescence from the through-bond conjugation. Given the equilibrated color-shifting fluorophores, they are rationally employed in a 3WJ-based rolling circle transcription switch, with the target-aptamer acting as an activator to achieve steric allosterism. This one-pot system allows the target to compete continuously for allosteric sites, and the activated transcription switches continue to amplify MGA forward, achieving accurate Aflatoxin 1 quantification at the picomolar level in 1 h. Due to the programmability of this RNA sensor, the design method of target-competitive aptamers is standardized, making it universally applicable. A simple strategy for deconjugating malachite green (MG) ligand in a reductive enzymatic environment is reported to manipulate the clusteroluminescence within isolated benzene rings. This strategy is then employed to construct a one-pot, ratiometric RNA sensor using an allosteric transcription-switch and rolling circle transcription. The RNA aptamer (MGA)-MG fluoresces red, while the reductive leucomalachite green (LMG) fluoresces in the UV region. image

Achieving selective transport of monovalent metal ions with high precision and permeability analogues to biological protein ion channels has long been explored for fundamental research and various applications, such as ion sieving, mineral extraction, and energy harvesting and conversion. However, it still remains a significant challenge to construct artificial nanofluidic devices to realize the trade-off effects between selective ion transportation and high ion permeability. In this work, we report a bioinspired functional micropipet with in situ growth of crown ether-encapsulated metal-organic frameworks (MOFs) inside the tip and realize selective transport of monovalent metal ions. The functional ion-selective micropipet with sub-nanochannels was constructed by the interfacial growth method with the formation of composite MOFs consisting of ZIF-8 and 15-crown-5. The resulting micropipet device exhibited obvious monovalent ion selectivity and high flux of Li+ due to the synergistic effects of size sieving in subnanoconfined space and specific coordination of 15-crown-5 toward Na+. The selectivity of Li+/Na+, Li+/K+, Li+/Ca2+, and Li+/Mg2+ with 15-crown-5@ZIF-8-functionalized micropipet reached 3.9, 5.2, 105.8, and 122.4, respectively, which had an obvious enhancement compared to that with ZIF-8. Notably, the ion flux of Li+ can reach up to 93.8 +/- 3.6 mol h(-1)m(-2) that is much higher than previously reported values. Furthermore, the functional micropipet with 15-crown-5@ZIF-8 sub-nanochannels exhibited stable Li+ selectivity under various conditions, such as different ion concentrations, pH values, and mixed ion solutions. This work not only provides new opportunities for the development of MOF-based nanofluidic devices for selective ion transport but also facilitates the promising practical applications in lithium extraction from salt-like brines, sewage treatment, and other related aspects.

A novel thermadapt shape memory polymer networks were prepared based on the conjugate addition reaction of quinone methide (QM) end-group-functionalized polycaprolactone and a thiol cross-linker, which can undergo the dynamic exchange reaction under thermal stimulation conditions. The resultant cross-linked polymers possessed excellent elasticity-based shape memory performance, cycle stability and solid-state plastically characteristics under high temperature conditions. This thermal-induced QM-thiol dynamic covalent click chemistry provided an effective method for realizing the solid-state plasticity of the polymers.

Lithium cobalt silicate Li 2 CoSiO 4 (LCSO) is a promising but challenging high energy‐density cathode for lithium‐ion battery. Herein, recent studies of synthesis–structure–performance of LCSO are reported, in which carbon coating, element doping, and nanostructure designs are incorporated in a two‐step synthesis starting with hydrothermal reaction. The initial performance is significantly improved with respect to previous reports in literature with the charge and discharge capacities now reaching 330 and 220 mAh g −1 , respectively. The discharge voltage platform is compatible with the 4 V window of the nonaqueous organic electrolytes and presents no structural‐change‐induced voltage drops. The striking finding from the study of LCSO is the oxygen redox activity amid the second lithium deintercalation process, in which peroxo formation dominates the charge compensation to the high‐voltage lithium capacity. First‐principles modeling reveals an intrinsic and general relation between oxygen redox and cationic disorder in bulk compounds. Thus, LCSO is a new prototype of polyanionic materials with oxygen redox, which is the foundation of high‐capacity Li‐rich cathodes. This review is also aimed to narrate the progresses of LCSO within a broad domain of Li 3 PO 4 ‐based polyanionic structures that support the development of solid‐state electrolytes for all solid‐state batteries.

An ionic liquid-modified reduced graphene oxide/polyaniline (RGO-IL/PANI) composite was synthesized successfully. The ionic liquid enlarged the interlayer distance of RGO sheets and acted as a PANI dopant to improve the orderly establishment of PANI. The supercapacitor based on RGO-IL/PANI presented outstanding energy density (24.1 W h kg-1 at 501 W kg-1), good cycling stability (91.5% capacity retention after 1000 cycles) and excellent flexibility. The results demonstrated the significant potential application of the obtained RGO-IL/PANI composite as a flexible electrode for high-performance energy storage devices.

The supercapacitor assembled by a RGO–IL material showed an outstanding energy density (50.19 W h kg−1) and could light an LED for 30 s.

Correction for ‘An ionic liquid-modified RGO/polyaniline composite for high-performance flexible all-solid-state supercapacitors’ by Chang Dong et al., Chem. Commun., 2020, DOI: 10.1039/d0cc04691d.

A biodegradable linear bio-based polyester of poly(hexylene succinate) was effectively prepared in non-metal sulfonic acid-functionalized Brønsted acidic ionic liquids (SFBAILs) as both the catalyst and the polymerization medium, and the processes of polycondensation and post-polycondensation in SFBAILs were also investigated. In addition, the side reactions which were detrimental to the growth of M w of poly(hexylene succinate) were evaluated and the synthesis mechanism of poly(hexylene succinate) catalyzed by SFBAILs was discussed with the help of DFT calculations. The result shows that both the imidazole ring and the sulfonic group on cations of SFBAILs play an important role in the catalytic process.

There is an urgent need for the development of novel positron emission tomography (PET) tracers for glioma imaging. In this study, we developed a novel PET probe ([18F]VUIIS1018A) by targeting translocator protein (TSPO), an imaging biomarker for glioma. The purpose of this preclinical study was to evaluate this novel TSPO probe for glioma imaging.

A series of starch-graft-poly (methyl methacrylate) (S-g-PMMA) copolymers were prepared by single electron transfer living radical polymerization (SET-LRP) at molecular level under mild conditions. The successful grafting polymerization was confirmed by FT-IR and 1H NMR spectroscopies. The hydrolysate of S-g-PMMA via acid-catalyzed hydrolysis proved to be a mixture of 1-arm, 2-arm and 3-arm polymers by MALDI-TOF measurements. Furthermore, the micelles formed by S-g-PMMA copolymers in water were studied at various conditions by SEM, TEM and DLS measurements. The results indicate that the sizes of micelles decreased following the order of the common solvents of 1,4-dioxane, tetrahydrofuran, acetone and acetonitrile, and also increased with the increase of initial copolymer concentrations, addition rate of water and length of grafted chains.

An efficient bimolecular ring-closure method is developed to prepare the well-defined cyclic polynorbornenes by combining the living ring-opening metathesis polymerization (ROMP) with the self-accelerating double strain-promoted azide-alkyne cycloaddition (DSPAAC) reaction. In this method, ROMP is used to synthesize the well-defined linear polynorbornenes with both azide terminals by virtue of a N-hydroxysuccinimide-ester-functionalized Grubbs initiator following the modification of polymer end groups. DSPAAC click reaction is then used to ring-close the linear polymer precursors and prepare the corresponding well-defined cyclic polynorbornenes using the sym-dibenzo-1,5-cyclooctadiene-3,7-diyne (DIBOD) as small linkers. The self-accelerating DSPAAC ring-closing reaction facilitates this method to efficiently prepare pure cyclic polynorbornenes in the presence of a molar excess of DIBOD small linkers to the linear polynorbornene precursors. This is the first report to prepare well-defined polynorbornenes with cyclic topology based on the ring-closure strategy for cyclic polymers.

This study firstly reports that low content of non-aggregated calcium hydroxide (Ca(OH)2) nano-spherulites (CNS) (200 ppm, diameters <5 nm) acting as cross-linkers pioneers highly stretchable self-healing PAA/CNS nanocomposite hydrogel (NC gel). Such NC gel exhibits increased mechanical properties (2300 % of tensile strain, 72 kPa of tensile strength, 0.611 MJ/m3 of toughness), excellent self-recovery (high recoverability against elongation of up to 1800% with tensile stress of 35 kPa), and most notably, remarkable self-healing ability (extensibility of 2100 % and toughness of 0.599 MJ/m3), suggesting even a small amount of CNS helps to establish a high stretchable and outstanding self-healing hydrogel.

Mechanically strong poly(acrylamide) nanocomposite hydrogels (NC gels), reinforced by calcium hydroxide nano-spherulites (CNS) with diameter <5 nm in the assistance of N,N'-methylenebisacrylamide (BIS), are fabricated via free radical polymerization. In traditional hydrogels using BIS as cross-linker, the existence of noncross-linked polymer chain tails leads to brittleness of hydrogels due to structural defects between adjacent clusters. However, CNS released by the tricalcium silicate can interconnect bare polymer chain tails at boundary of adjacent separated clusters and then connect vicinal clusters to form well-cross-linked network by reconstructing structural integrity of the cross-linked network in gels. Thus, our gels exhibit excellent mechanical behaviors, even considering low CNS content (200 ppm) in the presence of BIS clusters. Such NC gels can sustain high compressive stress (220MPa) at 97% strain and revert to its original size in 1 s after loading is released. The gels can also maintain similar mechanical strength after 10 cyclic compression tests, indicating the achievement of desirable self-recoverability. Furthermore, such gels could be stretched to 2200% strain with tensile stress of 920 kPa. The improved mechanical performance is ascribed to the homogeneous network structure in our NC gels reinforced by the synergistic effects of CNS and BIS clusters. (c) 2018 Elsevier Ltd.

The living ring-opening metathesis polymerization (ROMP) was demonstrated as a versatile method for preparing the well-defined polymers with aggregation-induced emission (AIE) property. In this approach, the norbornene-based monomers were prepared containing side groups of varied typical AIE fluorogens such as distyrenneanthracene (M1), 1,2,3,4,5-pentaphenylsiole (M2), and tetraphenylethene derivative (M3). Initiating by the Grubbs third generation catalyst (G3), ROMP could consume all of the exemplified monomers in less than 30 min and produce the corresponding well-defined AIE polymers of poly(M1), poly(M2), and poly(M3) with controlled molecular weight and narrow polydispersity. By copolymerizing with the norbornene-based monomer (M4) having poly(ethylene glycol) (PEG) side chain, ROMP could also produce the well-defined amphiphilic AIE block copolymers such as poly(M1)-b-poly(M4) and poly(M2)-b-poly(M4). Compared to norbornene-based AIE monomers, the resultant polymers showed enhanced AIE property, in which the same fluorescence intensity was obtained from the lower molar concentration of AIE fluorogen inside polymers than that inside monomers. In addition, the self-assembly of amphiphilic AIE block copolymers in selective solvents produced the fluorescent nanoparticles with varied morphologies and structures including spherical micelles, cylindrical micelles, and vesicles.

The amorphous mesoporous Ni(OH)(2) hollow spheres (Ni(OH)(2)-HSs) with waxberry-like morphology were fabricated by using a facile hydrothermal method with poly(styrene-acrylic acid) spheres as the template, followed by extraction of the template. In the hydrothermal process, Ni(NO3)(2)center dot 6H(2)O was employed as the precursor of Ni(OH)(2). SEM, TEM, XPS, XRD, and N-2 adsorption-desorption isotherm techniques were used to characterize the structure and morphology of Ni(OH)(2)-HSs. The obtained Ni(OH)(2)-HSs have a uniform morphology with an average diameter of 300 nm and shell thickness of about 25 nm. The mesoporous shells of the Ni(OH)(2)-HSs are composed of amorphous Ni(OH)(2) particles. When used as an electrode, the as-prepared Ni(OH)(2)-HSs exhibit pseudocapacitive behavior with a high specific capacitance of 2559 Fg(-1) at a scan rate of 1 mVs(-1) and a good capacitance retention of 91.8% after 1000 cycles at a current density of 5 Ag-1. These results suggest promising applications of the waxberry-like amorphous Ni(OH)(2) hollow spheres in electrode materials for supercapacitors.

Ligands play a vital role in atom transfer radical polymerization (ATRP) in solubilizing the transition-metal salt and adjusting the redox potential of the metal center. In general, nitrogen ligands work particularly well for copper-mediated ATRP, while phosphorus-based ligands are rarely used due to less effectiveness. Therefore, this work aims to explore for the first time a facile, simple, and inexpensive ionic liquid (IL), 1-phenyl-3-methylimidazole diphenyl phosphate ([Phmim][Ph2PO4]), as an efficient phosphorus ligand for CuBr2-mediated reverse ATRP. The key to success is ascribed to stronger complexation of the IL ligand with the catalyst and higher solubility of the resulting complex. The polymerizations proceeded in a controlled/“living” fashion, as evidenced by first-order kinetics, linear evolution of molecular weights with monomer conversion, and narrow molecular weight distributions. Effects of various experimental parameters—solvent, reaction temperature, IL, and molar ratio of CuBr2/[Phmim][Ph2PO4]—on the polymerization were investigated in detail. Furthermore, H NMR analysis confirmed the halogencontaining chain-end functionality of the resultant polymer.

In this paper, we reported that ZnO nanoparticles (NPs) film modified with C60 pyrrolidine tris-acid ethyl ester (PyC60) was used as cathode buffer layer in inverted polymer solar cells. The resultant device with a blend of PTB7:PC71BM as photoactive materials exhibited an open-circuit voltage (Voc) of 0.753V, a short-circuit current (Jsc) of 16.04mAcm−2, a fill factor (FF) of 72.5%, and an overall power conversion efficiency (PCE) of 8.76%. It was higher than the control devices based on sole ZnO NPs film or ZnO: PyC60 hybrid film as cathode buffer layer. It was found that the morphology improvement of ZnO/PyC60 film contributed to reducing series loss and interfacial charge recombination. In addition, it improved the interfacial contact with photoactive layer. The results increased electron injection and collection efficiency, and improved FF.

A facile, solution-processed method to fabricate MoO3 (s-MoO3) thin film as hole-injection layer (HIL) for poly(3-hexylthiophene) (P3HT) and (6,6)-phenyl-C61-butyric acid methyl ester (PC61BM) based organic bulk hetero-junction photovoltaics is presented. The structural, electronic property and surface microstructure of the s-MoO3 thin film are investigated in detail by X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, scanning electron microscopy and atomic force microscope. The results indicate that the s-MoO3 thin film possesses appropriate morphological, optical and electronic properties to be suitable for organic photovoltaic applications. The photovoltaic devices have been investigated and optimized in detail by tuning layer thickness, processing temperature and time, annealing conditions of interfacial layers. Using s-MoO3 thin film as hole-injection layer, the device gives open circuit voltage of 0.64V, circuit current density of 9.15mAcm−2, fill factor of 0.67 and power conversion efficiency of 3.92%, which is higher than the controlled device using PEDOT:PSS layer. In addition, the s-MoO3 based devices exhibit good stability.