Latest ArticlesEpoxy resin is widely used in electronic packaging due to its exceptional performance, particularly the low-temperature curable thiol/epoxy system, which effectively minimizes thermal damage to sensitive electronic components. However, the majority of commercial thiol curing agents contain hydrolysable ester bonds and lack rigid structures, which induces most of thiol/epoxy systems still suffering from unsatisfactory heat resistance and hygrothermal resistance, significantly hindering their application in electronic packaging. In this study, we synthesized a tetrafunctional thiol compound, bis[3-(3-sulfanylpropyl)-4-(3-sulfanylpropoxy)phenyl]sulfone (TMBPS) with rigid and ester-free structures to replace traditional commercial thiol curing agents, pentaerythritol tetra(3-mercaptopropionate) (PETMP). Compared to the PETMP/epoxy system, the TMBPS/epoxy system exhibited superior comprehensive properties. The rigid structures of bisphenol S-type tetrathiol enhanced the heat resistance and mechanical properties of TMBPS/epoxy resin cured products, outperforming those of PETMP/epoxy resin cured products. Notably, the glass transition temperature of TMBPS/epoxy resin cured products was 74.2 ℃ which was 11.8 ℃ higher than that of PETMP cured products. Moreover, the ester-free structure in TMBPS contributed to its enhanced resistance to chemicals and hygrothermal conditions. After undergoing 1000 h of high-temperature and high-humidity aging, the tensile strength and adhesion strength of TMBPS-cured products were 73.33 MPa and 3.39 MPa, respectively exceeding 100% and 40% of their initial values, while PETMP-cured products exhibited a complete loss of both tensile strength and adhesion strength. This study provides a strategy for obtaining thermosetting polymers that can be cured at low temperatures and exhibit excellent comprehensive properties.
Single-molecule junctions are building blocks for constructing molecular devices. However, intermolecular interactions like winding bring additional interference among the surrounding molecules, which inhibits the intrinsic coherent transport through single-molecule junctions. Here, we employed a nanocavity (dimethoxypillar[5]arene, DMP[5]), which is analogous to electric cables, to confine the conformation of flexible chains (1,8-diaminooctane, DAO) via host-guest interaction. Single-molecule conductance measurements indicate that the conductance of DAO encapsulated with DMP[5] is as high as that of pure DAO, as reproduced by theoretical simulations. Intriguingly, the molecular lengths of the DAO encapsulated with DMP[5] increase from 1.13 nm to 1.46 nm compared with the pure DAO, indicating that DMP[5] keeps DAO upright-standing via the confinement effect. This work provides a new strategy to decouple the intermolecular interaction by employing an insulating sheath, enabling the high-density integration of single-molecule devices.
Molecular catalysts can effectively steer the electrocatalytic acetylene semihydrogenation into ethylene, but realizing high Faradaic efficiency (FE) at industrial current densities remains a challenge. Herein, we report a ligand engineering strategy that utilizes polymeric N-heterocyclic carbene (NHC) as a hydrophobic ligand to modulate the microenvironment of Cu sites. This polymeric NHC imparts appropriate hydrophobic properties for the chelated Cu sites, thereby moderating the H2O transport and enabling easy access of acetylene. Consequently, the polymeric NHC chelated Cu exhibits an FEethylene of ~97% at a current density of 500 mA/cm2 in a flow cell. Particularly in a zero-gap reactor, the FEethylene consistently exceeds 86% across current densities from 100 mA/cm2 to 400 mA/cm2, reaching an optimal FEethylene of 98% at 200 mA/cm2 and achieving durable operation for 155 h at 100 mA/cm2. This work provides a promising paradigm to regulate the microenvironment of molecular catalysts for improving electrocatalytic performances under industrial current densities.
Carbon emissions from wastewater treatment contribute to global warming and have received widespread attention. It is necessary to seek low-carbon wastewater treatment technologies. Microbial fuel cells (MFC) and osmotic microbial fuel cells (OsMFC) are low-carbon technologies that enable both wastewater treatment and energy recovery. In this study, MFC and OsMFC were used to treat sulfamethoxazole (SMX) wastewater, and direct carbon emissions during operation was calculated. The highest SMX removal rate can reach about 40%. Simultaneously, the CH4 emission factor was significantly reduced to <6 g CO2/kg of chemical oxygen demand. The accumulation of SMX-degrading bacteria competed with methanogens for carbon source utilization, leading to a significant decrease in the relative abundance of methanogens. It is hoped that this study can provide a sustainable approach to antibiotic wastewater treatment and promote the development of low-carbon wastewater treatment technologies.
Electromagnetic wave-absorbing materials (EWAMs) are susceptible to failure in complex chemical environments. It is urgent to develop composites with high-efficiency electromagnetic wave (EMW) absorption and strong corrosion resistance. In the work, polyaniline (PANI) is in-situ polymerized on the surface of oxidized carbon nanohorns (ox-CNHs) to create a core-shell composite of ox-CNHs@PANI. By adjusting the thickness of the PANI shell and effectively regulating the electromagnetic parameters of the composite material, excellent impedance matching and efficient EMW absorption are achieved. At a thickness of 2.22 mm, the composite exhibits a reflection loss peak (RLmin) and a maximum effective absorption broadband (EAB) of −66.7 dB and 5.68 GHz, respectively. Additionally, the dense PANI shell effectively prevents contact between the corrosive medium and ox-CNHs, which significantly reduces the possibility of corrosion. Due to the formation of the ox-CNHs/PANI interface, the ox-CNHs@PANI composite exhibits strong corrosion resistance under acidic, alkaline, and neutral conditions. The ox-CNHs@PANI composite exhibits excellent EMW absorption and strong corrosion resistance, offering a new approach to developing advanced bifunctional materials.
Multi-metal porous crystalline materials (MPCM), integrating the functions of both multi-metal centres and porous crystalline materials (e.g., metal-organic frameworks (MOFs) and covalent organic frameworks (COFs)), are an extended class of porous materials that have attracted much attention for a broad range of applications. Owing to the advantages of these materials, they generally display high porosity, multi-metal active sites, well-tuned functions, and pre-designable structures, etc., serving as desired platforms for the study of structure-property relationships. In view of the clean and sustainable target, a series of MPCM have been explored as electrocatalysts for electrocatalytic reactions like hydrogen evolution reaction, oxygen evolution reaction and electrocatalytic CO2 reduction reaction. Concerning the progress achieved for MPCM in electrocatalytic field during past years, this review will provide a brief introduction on the recent breakthrough of MPCM based electrocatalysts including their synthesis methods, structure design, component/morphology tuning, electrocatalytic property and structure-property relationship, etc. Besides, it will also conclude the current challenges and present perspectives for the MPCM based electrocatalysts, which might promote the development of porous crystalline materials in electrocatalysis and hope to provide new insights for scientists in related fields.
A pair of asymmetric rigid carbazole-benzonitrile-based emitters were synthesized by strategically alternating donor and acceptor groups along the molecular edges. The spin-flip process is accelerated by both the formation of localized and delocalized charge transfer states due to linearly positioned donors and strong spin-orbital coupling between different excitation feature of the lowest singlet and triplet excited states. This molecular architecture results in a remarkable short delayed lifespan of around 100 ns. The application of the two emitters in organic light-emitting diodes (OLEDs) achieves the highest external quantum efficiencies of 13.0% for the green emitter and 9.1% for the sky-blue emitter. Impressively, these devices maintain their high efficiency even at high luminance levels. The sustained efficiency is ascribed to the effective suppression of exciton quenching by substantially shortening delayed lifespan. These findings underscore the practical utility of the molecular design strategy that incorporates alternate donor and acceptor groups at the molecular periphery for shortening delayed fluorescence lifetime, and hold great promise for the development of high-performance OLEDs.
Rapid carrier recombination and slow charge transfer dynamics have significantly reduced the performance of photocatalytic hydrogen production. Construction of heterojunctions via utilizing the sulfur-edge and metal-edge sites of metal sulfide semiconductor for improving photocatalytic activity remains a significant challenge. Herein, a novel ZnIn2S4/MnS S-scheme heterojunction was prepared by hydrothermal synthesis to accelerate charge carrier transfer for efficient photocatalysis. Notably, ZnIn2S4/MnS exhibited excellent photocatalytic hydrogen evolution activity (7.95 mmol g−1 h−1) under visible light irradiation (≥420 nm), up to 4.7 times higher than that of pure ZnIn2S4. Additionally, cycling experiments showed that ZM-2 remained high stability after four cycles. Density-functional theory (DFT) calculations and in situ XPS results confirm the formation of S-scheme heterojunction, indicating that the tight interfacial contact between ZnIn2S4 and MnS with the presence of Mn-S bonds (the unsaturated Mn edges of MnS and the uncoordinated S atoms in the edge of ZnIn2S4) promoted faster charge transfer. Besides, the unsaturated S atom on the surface of MnS is an active site with strong H+ binding ability, which can effectively reduce the overpotential or activation barrier for hydrogen evolution. This study illustrates the critical influence of the interfacial Mn-S bond on the ZnIn2S4/MnS S-scheme heterojunction to achieve efficient photocatalytic hydrogen production and provides relevant guidance for carrying out rational structural/interfacial modulation.
Bacterial pneumonia is one of the most common infectious diseases, a great threat to the health of children and the elderly. In the clinic, due to the extensive use of antibiotics, multi-drug-resistant bacteria have increased in large numbers, seriously affects the treatment of patients with bacterial pneumonia. With the development of nanomedicine, it shows great potential in the treatment of bacterial pneumonia. In this review, it initially comprehensively describes the pathological process of bacterial pneumonia and the current status of its clinical treatment. Then it summarizes the strategies of nanomedicine for the treatment of bacterial pneumonia, including inorganic nanomaterials, polymer nanoparticles, natural source nanomaterials and artificial antimicrobial peptides, with a focus on novel nanomaterials for the treatment of bacterial pneumonia (biomimetic nanomaterials, nanovaccines and genetically engineered nanomaterials). Finally, the prospect of nanomedicine for bacterial pneumonia therapy is discussed in the hope of providing new ideas for the clinical treatment of bacterial pneumonia.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
