MXene-Layered Double Hydroxide Reinforced Epoxy Nanocomposite with Enhanced Electromagnetic Wave Absorption, Thermal Conductivity, and Flame Retardancy in Electronic Packaging.

Due to the increased integration and miniaturization of electronic devices, traditional electronic packaging materials, such as epoxy resin (EP), cannot solve electromagnetic interference (EMI) in electronic devices. Thus, the development of multifunctional electronic packaging materials with superior electromagnetic wave absorption (EMA), high heat dissipation, and flame retardancy is critical for current demand. This study employs an in-situ growth method to load layered double hydroxides (LDH) onto transition metal carbides (MXene), synthesizing a novel composite material (MXene@LDH). MXene@LDH possesses a sandwich structure and exhibits excellent EMA performance, thermal conductivity, and flame retardancy. By adjusting the load of LDH, under the synergistic effect of multiple factors, such as dielectric and polarization losses, this work achieves an EMA material with a remarkable minimum reflection loss (RL) of -52.064 dB and a maximum effective absorption bandwidth (EAB) of 4.5 GHz. Furthermore, MXene@LDH emerges a bridging effect in EP, namely MXene@LDH/EP, leading to a 118.75% increase in thermal conductivity compared to EP. Simultaneously, MXene@LDH/EP contributes to the enhanced flame retardancy compared to EP, resulting in a 46.5% reduction in the total heat release (THR). In summary, this work provides a promising candidate advanced electronic packaging material for high-power density electronic packaging.

Toward Ultrahigh Thermoelectric Performance of Cu2 SnS3 -Based Materials by Analog Alloying.

Cu2 SnS3 is a promising thermoelectric candidate for power generation at medium temperature due to its low-cost and environmental-benign features. However, the high electrical resistivity due to low hole concentration severely restricts its final thermoelectric performance. Here, analog alloying with CuInSe2 is first adopted to optimize the electrical resistivity by promoting the formation of Sn vacancies and the precipitation of In, and optimize lattice thermal conductivity through the formation of stacking faults and nanotwins. Such analog alloying enables a greatly enhanced power factor of 8.03 µW cm-1 K-2 and a largely reduced lattice thermal conductivity of 0.38 W m-1  K-1 for Cu2 SnS3 - 9 mol.% CuInSe2 . Eventually, a peak ZT as high as 1.14 at 773 K is achieved for Cu2 SnS3 - 9 mol.% CuInSe2 , which is one of the highest ZT among the researches on Cu2 SnS3 -based thermoelectric materials. The work implies analog alloying with CuInSe2 is a very effective route to unleash superior thermoelectric performance of Cu2 SnS3 .

Optimizing heterotrophic nitrification process: The significance of demand-driven aeration and organic matter concentration.

Heterotrophic nitrification and aerobic denitrification (HNAD) sludge were successfully acclimated. The effects of organics and dissolved oxygen (DO) on nitrogen and phosphorus removal by the HNAD sludge were investigated. The nitrogen can be heterotrophically nitrified and denitrified in the sludge at a DO of 6 mg/L. The TOC/N (total organic carbon to nitrogen) ratio of 3 was found to result in removal efficiencies of over 88% for nitrogen and 99% for phosphorus. The use of demand-driven aeration with a TOC/N ratio of 1.7 improved nitrogen and phosphorus removal from 35.68% and 48.17% to 68% and 93%, respectively. The kinetics analysis generated an empirical formula, Ammonia oxidation rate = 0.08917·(TOC·Ammonia)0.329·Biomass0.342. The nitrogen, carbon, glycogen, and poly-ß-hydroxybutyric acid (PHB) metabolism pathways of HNAD sludge were constructed using the Kyoto Encyclopedia of Genes and Genomes (KEGG). The findings suggest that heterotrophic nitrification precedes aerobic denitrification, glycogen synthesis, and PHB synthesis.

Multifunctional Epoxy-Based Electronic Packaging Material MDCF@LDH/EP for Electromagnetic Wave Absorption, Thermal Management, and Flame Retardancy.

The sharp reduction in size and increase in power density of next-generation integrated circuits lead to electromagnetic interference and heat failure being a key roadblock for their widespread applications in polymer-based electronic packaging materials. This work demonstrates a multifunctional epoxy-based composite (MDCF@LDH/EP) with high electromagnetic wave (EMW) absorption, thermal conductivity, and flame retardancy performance. In which, the synergistic effect of porous structure and heterointerface promotes the multiple reflection and absorption, and dielectric loss of EMW. A low reflection loss of -57.77 dB, and an effective absorption bandwidth of 7.20 GHz are achieved under the fillings of only 10 wt%. Meanwhile, a 241.4% enhanced thermal conductivity of EP is due to the high continuous 3D melamine-derived carbon foams (MDCF), which provides a broad path for the transport of phonons. In addition, MDCF@LDH/EP composite exhibits high thermal stability and flame retardancy, thanks to the physical barrier effect of MDCF@LDH combined with the high temperature cooling properties of NiAl-LDH-CO3 2- . Compared with pure epoxy resin, the peak heat release rate and the total heat release rate are reduced by 19.4% and 30.7%, respectively. Such an excellent comprehensive performance enables MDCF@LDH/EP to a promising electronic packaging material.

Bio-inspired antibacterial cellulose paper-poly(amidoxime) composite hydrogel for highly efficient uranium(vi) capture from seawater.

A bio-inspired cellulose paper-poly(amidoxime) composite hydrogel is explored via UV-polymerization. This hydrogel has a highly efficient uranium capture capacity of up to 6.21 mg g-1 for WU/Wdry gel and 12.9 mg g-1 for WU/Wpoly(amidoxime) in seawater for 6 weeks, due to its enhanced hydrophilicity, good hydraulic/ionic conductivity and broad-spectrum antibacterial performance.