BODIPY-based macrocycles Qin, Yi; Liu, Xi; Jia, Pei-Pei ...
Chemical Society reviews,
08/2020, Letnik:
49, Številka:
16
Journal Article
Recenzirano
During the past few years, the construction of BODIPY-based macrocycles has attracted extensive interest due to the widespread applications of these materials in sensing, bioimaging, molecular ...machines, and photodynamic therapy (PDT). Since significant progress has been made in this field, it is time to summarize the recent developments involving BODIPY-based macrocycles. In this review, we will briefly introduce the synthesis routes of BODIPY-based macrocycles, including a covalent synthetic protocol and a noncovalent self-assembly protocol. In addition, we will discuss the photophysical and photochemical properties and the applications of these BODIPY-based macrocycles in the areas of sensing, bioimaging, photodynamic therapy,
etc.
This review comprehensively summarized the construction of BODIPY-based macrocycles and their properties as well as applications.
Over the past few years, the fabrication of artificial light‐harvesting systems with aggregation‐induced emission (AIE) has attracted significant attention because of the wide applications of these ...systems in organic chemistry, supramolecular chemistry, energy chemistry, and even materials science. This progress report focuses on recent advances in the design and preparation of artificial light‐harvesting systems with AIE. In addition, the properties, functions, and applications of these systems are discussed.
Recent progress in the fabrication of supramolecular artificial light‐harvesting systems with aggregation‐induced emission is reviewed, with an emphasis on their preparation, properties, functions, and applications. The future challenges and potential research opportunities are also discussed. Such artificial light‐harvesting systems will attract increasing attention and play an important role in supramolecular chemistry, energy chemistry, and materials science over the next decades.
Furfural is a promising renewable platform compound derived from lignocellulosic biomass that can be further converted to biofuels and biochemicals. The highly functionalized molecular structure of ...furfural makes it a desired raw material for the sustainable production of value-added chemicals containing oxygen atoms. The conversion of furfural to C4 and C5 chemicals by various catalytic processes is reviewed. The C5 chemicals are mainly produced through sequential steps of selective hydrogenation and/or hydrogenolysis, while most of the C4 chemicals are synthesized with selective oxidation as the first step. This review divides the chemical products from furfural into several groups according to their carbon numbers and synthesis routes, with emphasis on the catalysts and reaction mechanisms. The applications of these chemicals and their traditional production from fossil feedstocks have also been added as background information. Additionally, recent advances in the development of heterogeneous catalysts for furfural production are briefly reviewed.
Abstract
Dielectric elastomer actuators (DEAs) with large electrically-actuated strain can build light-weight and flexible non-magnetic motors. However, dielectric elastomers commonly used in the ...field of soft actuation suffer from high stiffness, low strength, and high driving field, severely limiting the DEA’s actuating performance. Here we design a new polyacrylate dielectric elastomer with optimized crosslinking network by rationally employing the difunctional macromolecular crosslinking agent. The proposed elastomer simultaneously possesses desirable modulus (~0.073 MPa), high toughness (elongation ~2400%), low mechanical loss (tan
δ
m
= 0.21@1 Hz, 20 °C), and satisfactory dielectric properties (
$${\varepsilon }_{{{\rm{r}}}$$
ε
r
= 5.75, tan
δ
e
= 0.0019 @1 kHz), and accordingly, large actuation strain (118% @ 70 MV m
−1
), high energy density (0.24 MJ m
−3
@ 70 MV m
−1
), and rapid response (bandwidth above 100 Hz). Compared with VHB
TM
4910, the non-magnetic motor made of our elastomer presents 15 times higher rotation speed. These findings offer a strategy to fabricate high-performance dielectric elastomers for soft actuators.
Polymer‐based dielectrics have received intensive interest from academic community in the field of high‐power energy storage owing to their superior flexibility and fast charge–discharge ability. ...Recently, how to suppress the loss of polymer‐based dielectrics has been increasingly recognized as a critical point to attain a high charge–discharge efficiency in the film capacitors. Some achievements are made in analyzing the source of loss and suppressing loss via Edison's trial and error method. In this review, the significance of suppressing loss in polymer‐based dielectrics is firstly emphasized. Then, different sources of loss are discussed carefully and an in‐depth analysis of the related measurements is presented. Next, recent research results in suppressing loss are summarized and discussed in detail according to different strategies. Finally, the challenges and opportunities in the loss suppression research for the rational design of high‐efficiency polymer‐based dielectrics are proposed.
How to suppress the loss of polymer‐based dielectrics has been increasingly recognized as a critical point to attain a high charge–discharge efficiency in the film capacitors. The theoretical progress, measurement of properties, and development of materials are reviewed. The challenges and opportunities in loss suppression research for the rational design of high‐efficiency polymer‐based dielectrics are proposed.
There have been rapid increases in consumer products containing nanomaterials, raising concerns over the impact of nanoparticles (NPs) to humankind and the environment, but little information has ...been published about mineral filters in commercial sunscreens. It is urgent to develop methods to characterize the nanomaterials in products. Titanium dioxide (TiO2) and zinc oxide (ZnO) NPs in unmodified commercial sunscreens were characterized by laser scanning confocal microscopy, atomic force microscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results showed that laser scanning confocal microscopy evaluated primary particle aggregates and dispersions but could not size NPs because of the diffraction limited resolution of optical microscopy (200 nm). Atomic force microscopy measurements required a pretreatment of the sunscreens or further calibration in phase analysis, but could not provide their elemental composition of commercial sunscreens. While XRD gave particle size and crystal information without a pretreatment of sunscreen, TEM analysis required dilution and dispersion of the commercial sunscreens before imaging. When coupled with energy-dispersive X-ray spectroscopy, TEM afforded particle size information and compositional analysis. XRD characterization of six commercial sunscreens labeled as nanoparticles revealed that three samples contained TiO2 NPs, among which two listed ZnO and TiO2, and displayed average particle sizes of 15 nm, 21 nm, and 78 nm. However, no nanosized ZnO particles were found in any of the samples by XRD. In general, TEM can resolve nanomaterials that exhibit one or more dimensions between 1 nm and 100 nm, allowing the identification of ZnO and TiO2 NPs in all six sunscreens and ZnO/TiO2 mixtures in two of the samples. Overall, the combination of XRD and TEM was suitable for analyzing ZnO and TiO2 NPs in commercial sunscreens.
Here, the reduction chemistry of mono- and binuclear α-diimine-Re(CO)
complexes with proton responsive ligands and their application in the electrochemically-driven CO
reduction catalysis are ...presented. The work was aimed to investigate the impact of 1) two metal ions in close proximity and 2) an internal proton source on catalysis. Therefore, three different Re complexes, a binuclear one with a central phenol unit, 3, and two mononuclear, one having a central phenol unit, 1, and one with a methoxy unit, 2, were utilised. All complexes are active in the CO
-to-CO conversion and CO is always the major product. The catalytic rate constant k
for all three complexes is much higher and the overpotential is lower in DMF/water mixtures than in pure DMF (DMF=N,N-dimethylformamide). Cyclic voltammetry (CV) studies in the absence of substrate revealed that this is due to an accelerated chloride ion loss after initial reduction in DMF/water mixtures in comparison to pure DMF. Chloride ion loss is necessary for subsequent CO
binding and this step is around ten times faster in the presence of water 2: k
(DMF)≈1.7 s
; k
(DMF/H
O)≈20 s
. The binuclear complex 3 with a proton responsive phenol unit is more active than the mononuclear complexes. In the presence of water, the observed rate constant k
for 3 is four times higher than of 2, in the absence of water even ten times. Thus, the two metal centres are beneficial for catalysis. Lastly, the investigation showed that the phenol unit has no impact on the rate of the catalysis, it even slows down the CO
-to-CO conversion. This is due to an unproductive, competitive side reaction: After initial reduction, 1 and 3 loose either Cl
or undergo a reductive OH deprotonation forming a phenolate unit. The phenolate could bind to the metal centre blocking the sixth coordination site for CO
activation. In DMF, O-H bond breaking and Cl
ion loss have similar rate constants 1: k
(DMF)≈2 s
, k
≈1.5 s
, in water/DMF Cl
loss is much faster. Thus, the effect on the catalytic rate is more pronounced in DMF. However, the acidic protons lower the overpotential of the catalysis by about 150 mV.
Soil-borne fungal pathogens that cause crop disease are major threats to agriculture worldwide. Here, we identified a secretory polysaccharide deacetylase (PDA1) from the soil-borne fungus ...Verticillium dahliae, the most notorious plant pathogen of the Verticillium genus, that facilitates virulence through direct deacetylation of chitin oligomers whose N-acetyl group contributes to host lysine motif (LysM)-containing receptor perception for ligand-triggered immunity. Polysaccharide deacetylases are widely present in fungi, bacteria, insects and marine invertebrates and have been reported to possess diverse functions in developmental processes rather than virulence. A phylogenetics analysis of more than 5,000 fungal proteins with conserved polysaccharide deacetylase domains showed that the V. dahliae PDA1-containing subtree includes a large number of proteins from the Verticillium genus as well as the Fusarium genus, another group of characterized soil-borne fungal pathogens, suggesting that soil-borne fungal pathogens have adopted chitin deacetylation as a major virulence strategy. We showed that a Fusarium PDA1 is required for virulence in cotton plants. This study reveals a substantial virulence function role of polysaccharide deacetylases in pathogenic fungi and demonstrates a subtle mechanism whereby deacetylation of chitin oligomers converts them to ligand-inactive chitosan, representing a common strategy of preventing chitin-triggered host immunity by soil-borne fungal pathogens.
Polymer‐based film capacitors with high breakdown strength and excellent flexibility are crucial in the field of advanced electronic devices and electric power systems. Although massive works are ...carried to enhance the energy storage performances, it is still a great challenge to improve the energy density of polymer composites under the premise of large‐scale industrial production. Herein, a general strategy is proposed to improve the intrinsic breakdown strength and energy storage performances by blending core‐shell structured methyl methacrylate‐butadiene‐styrene (MBS) rubber particles into a polymer matrix. Good compatibility and uniform dispersion state of MBS particles are observed in the matrix. Polarizing microscopy images show that blended films exhibit clear reduction of crystalline grains with the addition of MBS particles. Accordingly, an increased breakdown strength of 515 MV m−1 and discharged energy density of 12.33 J cm−3 are observed in poly(vinylidene fluoride‐co‐hexafluoropropylene)‐based composite films. Through comprehensive characterizations, it is believed that the superior energy storage performance of composite films is attributed to decreased crystalline grains, improved mechanical properties, and restriction on carrier motion. These results provide a novel design of dielectric polymers for high breakdown strength and discharged energy density applications.
All‐organic dielectrics are fabricated by blending core‐shell structured methyl methacrylate‐butadiene‐styrene rubber particles and poly(vinylidene fluoride‐co‐hexafluoropropylene) through solution casting method. The blended composite films are found to increase the breakdown strength and discharged energy density of the polymer matrix. The all‐organic films with quick/simple fabrication, improved dielectric, and energy storage performances provide a novel design of dielectrics for energy storage applications.
Polymer dielectrics for energy storage applications usually endure high electric field strength. Adjustment of the composition and structure of the dielectric bulk phase to enhance the dielectric ...breakdown strength has been widely studied. However, the effect of electrode-dielectric interface on the breakdown strength has received little attention, which greatly hinders further development in this field. In this work, an all-organic double-layer dielectric film consisting of poly(vinylidene fluoride) (PVDF) as the matrix and polymethyl methacrylate (PMMA) as the organic nano-interlayer was prepared. By adjusting the electrode-dielectric interface, remarkably improved electric breakdown strength (767.05 MV m
−1
) and discharged energy density (19.08 J cm
−3
) were realized concurrently without sacrificing the charge-discharge efficiency. The experimental results and computational simulations reveal that the surface morphology of dielectrics has a great effect on the electric field distribution at the electrode-dielectric interface, and further affects the leakage current and breakdown strength of the dielectric. The PMMA nano-interlayer modifies the surface defects and increases the Young's modulus at the electrode-dielectric interface, leading to the improvement of insulation performance. These findings offer a new perspective to understand the impact of the electrode-dielectric interface on the polymer dielectric breakdown strength. This work provides a novel paradigm for fabricating polymer dielectrics with high breakdown strength for energy storage.
The surface morphology of dielectric films has a great effect on the insulation performance. Remarkably improved capacitive performance is realized by adjusting the electrode-dielectric interface.
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