Random copolymerization of macromonomers as a versatile strategy to synthesize mixed-graft block copolymers

The random copolymerization of norbornene-functionalized macromonomers was explored as a method of synthesizing mixed-graft block copolymers (mGBCPs). The copolymerization kinetics of a model system of polystyrene (PS) and poly(lactic acid) (PLA) macromonomers was first analyzed, revealing a gradient composition of side chains along the mGBCP backbone. The phase separation behavior of mGBCPs with PS and PLA side chains of various backbone lengths and side chain molar ratios was investigated, and increasing the backbone length was found to stabilize the phase-separated nanostructures. The graft architecture was also demonstrated to improve the processability of the mGBCP, compared to a linear counterpart. Investigations of mGBCPs comprised of polydimethylsiloxane and poly(ethylene oxide) side chains exemplified the diverse self-assembled morphologies, including a Frank-Kasper A15 phase, that can be obtained with mGBCPs synthesized by random copolymerization of macromonomers. Lastly, a ternary mGBCP was synthesized by the copolymerization of three macromonomers.     

Understanding cathode materials in aqueous zinc–organic batteries

Organic electrode materials (OEMs) are being investigated as promising candidates for aqueous zinc-ion batteries (AZIBs) owing to their environmental friendliness, cost-effectiveness, and structural diversity, and tunability. Understanding the correlation between structural regulation of OEMs and their electrochemical property in AZIBs is vital to rational design of OEMs. Herein, we first discuss the fundamentals of the energy storage mechanism of OEMs. Then, strategies to improve the electrochemical performance, including the specific capacity, voltage, rate capability, and cycling stability, are elaborated from the perspective of molecular engineering. Finally, we share our views on the remaining challenges and prospects of OEMs in AZIBs.     

BiVO4/TiO2 heterojunction with rich oxygen vacancies for enhanced electrocatalytic nitrogen reduction reaction

The large-scale production of ammonia mainly depends on the Haber–Bosch process, which will lead to the problems of high energy consumption and carbon dioxide emission. Electrochemical nitrogen fixation is considered to be an environmental friendly and sustainable process, but its efficiency largely depends on the activity and stability of the catalyst. Therefore, it is imperative to develop highefficient electrocatalysts in the field of nitrogen reduction reaction (NRR). In this paper, we developed a BiVO₄/TiO₂ nanotube (BiVO₄/TNT) heterojunction composite with rich oxygen vacancies as an electrocatalytic NRR catalyst. The heterojunction interface and oxygen vacancy of BiVO₄/TNT can be the active site of N₂ dynamic activation and proton transition. The synergistic effect of TiO₂ and BiVO₄ shortens the proton transport path and reduces the over potential of chemical reaction. BiVO₄/TNT has high ammonia yield of 8.54 μg·h⁻¹·cm⁻² and high Faraday efficiency of 7.70% in −0.8 V vs. RHE in 0.1 M Na₂SO₄ solution.     

Hydrothermal LiFePO4 as an Artificial Enzyme to Mimic Peroxidase and Its Applications to Glucose Detection

Journal of Analytical Chemistry - Lithium iron phosphate materials as one of the most representative cathode materials for lithium-ion battery were found to possess intrinsic peroxidase-like...     

Multi-emissive 1D Cd(II) polymers with a biphenyl bridged bisazamacrocycle for ratiometric discrimination of nitroaromatics and selective visual detection of picric acid

Three one-dimensional ladder-like coordination polymers consisting of Cd₆ metalloring as the building unit, {[Cd₄LCl₄]·3H₂O}_n ( 1 ), {[Cd₃L(ClO₄)(H₂O)]ClO₄·3H₂O}_n ( 2 ), and {[Cd₆(L)₂(NO₃)₂(CH₃OH)(H₂O)](NO₃)₂·2CH₃OH·5H₂O}_n ( 3 ), were solvothermally constructed from a carboxylic functionalized bisazamacrocyclic ligand 4,4′-bis((4,7-bis(2-carboxyethyl)-1,4,7-triazacyclonon-1-yl)methyl)-1,1′-biphenyl (H₄L). These compounds dispersed in ethanol show the multiple emissions originating from the monomeric and intramolecularly overlapping biphenyl moieties which could be sensitively quenched by picric acid (PA) and 4-nitrophenol (4-NP) through the effective fluorescence resonance energy transfer process. The differential fluorescent responses of each compound on exposure to PA and 4-NP individually make the convenient ratiometric discrimination of two analytes based on the fluorescent intensity ratio (I₃₂₀/I₃₆₀) attainable, and 1 and 2 as ratiometric chemosensors for PA present a broad linear detection range from 4 to 300 μM with detection limits of 0.84 and 0.93 μM, respectively. Furthermore, the blue light emission of 1 under an ultraviolet lamp could be selectively quenched by PA even in the presence of all other interfering nitroaromatic pollutants, which empowers the fast visual detection of PA by naked eye.     

High-throughput lipidomics analysis to discover lipid biomarkers and profiles as potential targets for evaluating efficacy of Kai-Xin-San against APP/PS1 transgenic mice based on UPLC–Q/TOF–MS

Lipid metabolism has a significant function in the central nervous system and Alzheimer's disease (AD) is an age-related senile disease characterized by central nerve degeneration. The pathological development of AD is closely related to lipid metabolism disorders. To reveal the influence of Kai-Xin-San (KXS) on lipid metabolism in APP/PSI transgenic mice and potential therapeutic targets for treating AD, brain tissue samples were collected and analyzed by high-throughput lipidomics based on UPLC–Q/TOF-MS. The collected raw data were processed by multivariate data analysis to discover the potential biomarkers and lipid metabolic profiles. Compared with the control wild-type mouse group, nine potential lipid biomarkers were found in the AD model group, of which seven were up-regulated and two were down-regulated. Orally administrated KXS can reverse the changes in these potential biomarkers. Compared with the model group, a total of six differential metabolites showed a recovery trend and may be potential targets for KXS to treat AD. This study showed that high-throughput lipidomics can be used to discover the perturbed pathways and lipid biomarkers as potential targets to reveal the therapeutic effects of KXS.     

Spectrum–effect relationship of antioxidant and anti-inflammatory activities of Laportea bulbifera based on multivariate statistical analysis

Laportea bulbifera, named Hong He Ma in Chinese, is a Chinese herbal medicine commonly used by the Miao nationality of China. In this study, 43 batches of L. bulbifera were collected from different origins in China. Ethanol, ethyl acetate and petroleum ether were used to prepare different extracts of the plant. UHPLC technique was used to establish the fingerprints, whereas DPPH assay and RAW264.7 inflammatory cell models were used to evaluate the antioxidant and anti-inflammatory activities, respectively. Moreover, the spectrum–effect relationship between relative peak area of common peaks and efficacy value was set up by multivariate statistical analysis. Furthermore, 10 batches were selected randomly for validation of those models. The results showed that ethyl acetate and petroleum ether extracts possess excellent antioxidant and anti-inflammatory activities, respectively. Peaks A₆ and A₇ demonstrated the greatest antioxidant activity, while peak A₁₇ showed the strongest anti-inflammatory activity. After a verified experiment, the result was obtained and illustrated that the spectrum–effect relationship which we established could reliably infer antioxidant and anti-inflammatory compounds of the Chinese herbal medicine.