Latest ArticlesWater pollution caused by Hg(II) and Ag(I) poses deleterious effects to environmental safety. Adsorption is one of the promising methods to decontaminate aqueous metal ions. Herein, polyhydroxyl-capped poly(amidoamine) (PAMAM) dendrimer/silica composites (G1-OH and G2-OH) were prepared for decontaminating aqueous Hg(II) and Ag(I). The maximum adsorption capacity of G1-OH and G2-OH for Hg(II) are 0.45 and 0.76 mmol/g, while that for Ag(I) are 0.66 and 0.81 mmol/g. The optimum solution pH for the adsorption of Hg(II) and Ag(I) are both 6. The adsorption for Hg(II) and Ag(I) can reach equilibrium at 150 and 120 min, respectively. Pseudo-second-order model can be used to describe the adsorption kinetic process and the rate-controlling step is film diffusion process. Adsorption isotherm indicates the adsorption can be promoted by increasing concentration and temperature, and the adsorption process could be described by Langmuir model with chemical mechanism. G1-OH and G2-OH exhibit excellent adsorption selectivity and they can 100% adsorb Hg(II) or Ag(I) with the coexisting of Fe(III), Co(II), Cu(II) or Ni(II). Adsorption mechanism confirms C-N, OH and CONH groups play critical role for the adsorption of the two ions. The work may provide efficient adsorbents for the decontamination of aqueous Hg(II) and Ag(I) with practical value.
Temperature plays a crucial role in regulating polymorphism in supramolecular polymers. Understanding the mechanism behind temperature-dependent supramolecular polymorphism is crucial as it provides an opportunity to tailor polymorphs for specific properties and applications. In this study, we present our findings on a naphthalimide-substituted benzene-1,3,5-tricarboxamide derivative, R-Nap-1, which exhibits two distinct polymerization pathways at varying temperatures. At 313 K, polymerization results in the formation of an M-chiral polymorph, whereas at 253 K, a P-chiral polymorph is formed. Both polymorphs are notably stable, remaining unchanged for over six months under ambient conditions. Theoretical calculations and experimental investigations allowed us to elucidate the mechanisms underlying these polymorphic transformations. The formation of the M-chiral polymorph at 313 K is attributed to the nucleation and growth of R-Nap-1 monomers once their concentration surpasses a critical threshold. Conversely, at lower temperatures (e.g., 253 K), the monomers undergo facile transformation into dimers due to a lower energy barrier and reduced Gibbs energy compared to the monomeric state. Subsequently, these dimers undergo nucleation-elongation to form the P-chiral polymorph when their concentration exceeds the critical polymerization concentration. The stability and lack of interconversion between the two polymorphs can be attributed to their close thermodynamic stabilities, as evidenced by variable-temperature CD spectra and DFT calculations. These findings highlight the importance of accurate temperature control in supramolecular polymerization processes, making a significant contribution to the understanding of supramolecular polymorphism, thus advancing the field of supramolecular chemistry.
Organic semiconductors are promising candidates as active layers in flexible and biocompatible electronics owing to their solution processability and molecular design flexibility. However, it remains necessary to establish a green processing approach to acquire desirable electrical properties for scalable industrial applications. Here, a highly efficient and environmentally friendly post-treatment method using liquid nitrogen as a cooling bath is developed to optimize the aggregation structure and electrical performance of organic semiconductors. The carrier mobility has increased by nearly 60% with this treatment, achieving a performance boost comparable to that of traditional annealing methods. This performance improvement is attributable to the denser aggregation structure and enhanced molecular ordering compared with those of as-cast semiconducting polymer films. Impressively, the entire process can be completed within a few minutes without additional vacuum or high-temperature conditions, offering an economical and efficient alternative to traditional methods. Furthermore, the enhancement effect and long-term stability of this treatment are validated across a wide range of organic semiconductors, positioning this green and versatile approach as a promising substitute for conventional post-treatment, thereby facilitating the development of next-generation sustainable electronics.
The sequestration of 99Tc represents one of the most challenging tasks in nuclear waste decontamination. In the event of a radioactive waste leak, 99TcO4– (a main form of 99Tc) would spread into the groundwater, a scenario difficult to address with conventional anion exchange materials like resin and inorganic cationic sorbents. Herein, we present a nickel(Ⅱ) metal-organic framework (MOF), TNU-143, featuring 3D four-fold interpenetrated networks. TNU-143 exhibits efficient ReO4– (a nonradioactive analogue of 99TcO4–) removal with fast anion exchange kinetics (< 1 min), high sorption capacity (844 mg/g for ReO4–), and outstanding selectivity over common anions. More importantly, TNU-143 shows superior stability in alkaline solution and can remove 91.6% ReO4– from simulated alkaline high-level waste (HLW) streams with solid-liquid ratio of 40 g/L. The uptake mechanism is elucidated by the single-crystal structure of TNU-143(Re), showing that ReO4– anions are firmly coordinated to nickel cation to result in a 2D layered structures. Density functional theory (DFT) calculations confirm the transformation from TNU-143 to TNU-143(Re) is a thermodynamically favorable process. This work presents a new approach to the removal of ReO4–/99TcO4– from alkaline nulcear fuel using MOF sorbents.
Higher initial (de)hydrogenation temperature and sluggish kinetics are the main bottlenecks to develop Mg-based hydrogen storage alloys with high hydrogen capacity. One of the effective methods of solving these problems is introducing additives to enhance (de)hydrogenation kinetics and decrease particle sizes to lower (de)hydrogenation temperatures. In this work, Mg85-Ni10-La4.5-Y0.5 alloy doped with Cu@C nanoparticles is prepared, which could enhance (de)hydrogenation kinetics via introducing Cu nanoparticles as a catalyst and reduce the alloy particle sizes via acting as a grinding agent to lower (de)hydrogenation temperature. The results indicate the dehydrogenation temperature of the modified Mg85-Ni10-La4.5-Y0.5 composite could be decreased to 308.5 ℃, absorb 4.73 wt% H2 at 220 ℃ within 1 min and release 5.01 wt% H2 within 4 min at 300 ℃. Moreover, the capacity retention could be maintained around 98.8% after 10 cycles at 300 ℃, superior than those of Mg85-Ni10-La4.5-Y0.5 and milled-Mg85-Ni10-La4.5-Y0.5. DFT results and characterizations suggest that in-situ formed Mg2Cu could accelerate the dissociation of Mg-H bonds and the presence of amorphous carbon in Mg-Ni-La-Y-Cu system will further synergistically improve the (de)hydrogenation kinetics of Mg85-Ni10-La4.5-Y0.5. Reduced particle sizes under the aid of carbon frameworks also help introduce boundaries of the particles and shorten hydrogen diffusion pathways.
Silicon based (Si-based) materials are considered to be the most promising anode materials for lithium-ion batteries (LIBs) due to their high specific capacity. However, the issues of poor electrical conductivity and volume expansion during cycling have not been effectively addressed. The optimum remedy is to select specific materials to establish an exceptional conductive and volume buffer structure to assist the Si materials to develop its excellent lithium storage properties. Here, Si particles were encapsulated into porous carbon fibers containing ultrafine Co particles (CP) to obtained Si-x@CP-y film. Among them, the addition of Si particles and the void structure was precisely regulated to achieve a superior electrode with a high specific capacity. Subsequently, the two-dimensional conductive material reduced graphene oxide (rGO) nanosheets were further incorporated to obtain Si-2@CP-2@rGO films with core@multi-shell structure. The final electrode was equipped with one-, two-, and three-dimensional electronic pathways to allow rapid electron transport, and featured with multi-layer buffer structure and reserved pores that could effectively mitigate volume changes. As expected, the free-standing Si-2@CP-2@rGO electrode delivered a high specific capacity of 1221.2 mAh/g after 100 cycles at 0.1 A/g in a half cell, and the assembled full cell showed 249.0 mAh/g after 200 cycles at 0.2 A/g, which fulfilled the lightweight requirement for new energy storage devices.
The battery energy density can be improved by raising the operating voltage, however, which may lead to rapid capacity decay due to the continuous electrolyte decomposition and the thickening of electrode electrolyte interphases. To address these challenges, we proposed tripropyl phosphate (TPP) as an additive−regulating Li+ solvation structure to construct a stable LiF–rich electrode carbonate−based electrolyte interphases for sustaining 4.6 V Li||LiCoO2 batteries. This optimized interphases could help reduce the resistance and achieve better rate performance and cycling stability. As expected, the Li||LiCoO2 battery retained 79.4% capacity after 100 cycles at 0.5 C, while the Li||Li symmetric cell also kept a stable plating/stripping process over 450 h at the current density of 1.0 mA/cm2 with a deposited amount of 0.5 mAh/cm2.
Selenium (Se) plays an important role in the development and treatment of lung cancer, yet its specific mechanisms remain elusive. Lower Se level in serum was noted in lung cancer patients compared to normal controls. Therefore, developing effective therapeutic adjuvants containing Se might benefit the treatment of lung cancer patients. This study aimed to investigate the association between Se and the chemotherapeutic efficacy of lung cancer. Lentinan-modified selenium nanoparticles (LET-SeNPs) were created to develop and verify the effectiveness of Se containing adjuvant applied with pemetrexed on lung cancer cells. A synergistic effect was observed between LET-SeNPs and pemetrexed in vitro. The combination of LET-SeNPs and pemetrexed could induce reactive oxygen species overproduction, mitochondrial dysfunction and DNA damage, ultimately leading to cancer cell apoptosis. It is implied that LET-SeNPs might be a promising sensitizer to pemetrexed chemotherapy and could potentially enhance chemotherapy efficiency in non-small cell lung cancer.
As the main organ of gas exchange, the lungs are susceptible to various exogenous attacks, and pneumonia is one of the major inflammatory diseases that threaten human health. Generally, pneumonia is a disease that occurs in the alveoli and respiratory bronchioles induced by pathogens and further causes local and systemic inflammatory responses. The development of pneumonia can bring various serious complications, including lung abscess, sepsis, meningitis, brain damage and hearing loss. Over the past few decades, the mortality rate of pneumonia patients has remained high. While lung cancer is another lung-related malignant tumors worldwide, with a low 5 year survival rate. Exploring the mechanisms of their occurrence and interaction between pneumonia and lung cancer is a challenging and meaningful task. The abnormalities of lipid droplets (LDs) polarity have been found strongly accompanied by many diseases, especially cancer, inflammation, and metabolic diseases. However, their exact role is not yet clear. Hence, it is significant to develop a novel detection method to observe the polarity changes of LDs, which would help to reveal the development process of diseases pneumonia and lung cancer. In this work, a new polarity-sensitive LDs-targeted near-infrared probe BFZ up to 712 nm was designed, according to the intramolecular charge transfer mechanism, which displayed high fluorescence intensity in low polarity while showing decreased fluorescence intensity in high-polarity conditions with a significant redshift. The BFZ was successfully applied to the change of LDs polarity in lipopolysaccharide (LPS)-stimulated A549 cells, and a mouse model of lung inflammation. It also tells the polarity differences between normal and tumor cells and between normal and tumor tissues. Moreover, the correlations between pneumonia and polarity changes were observed through the imaging experiments, which may provide an insightful method for the early diagnosis of pneumonia and lung cancer.
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