Chemical Papers最新文献

Membrane distillation (MD) as thermal-driven membrane separation commonly uses hydrophobic membrane, but this membrane has limitation due to wetting issues from low surface tension liquids, such as oils and surfactants. The strategic improvement to overcome the wetting issue is via omniphobic surface modification as it has the ability to repel low surface tension liquids. This research aims to fabricate and evaluate the anti-wetting properties of omniphobic polyvinylidene fluoride (PVDF) membrane modified with ZnO nanoparticles (ZnO Nps) as the re-entrant structure and palmitic acid (PA) as “green material” of the hydrophobic agent. The deposition of ZnO Nps was carried out using dip coating approach with variations of ZnO Nps loadings (1, 2, and 3 wt%) and then followed by palmitic acid surface grafting with various immersion times of 3, 6, 12, and 24 h. The developed omniphobic membrane was characterized using contact angle goniometer, scanning electron microscope (SEM), atomic force microscope (AFM), liquid entry pressure test, and leaching test. The results showed that the modification with ZnO Nps and palmitic acid obtained contact angle above 90° when tested with water, ethylene glycol, and 0.4 mM sodium dodecyl sulfate (SDS), which meets the omniphobic criteria. The presence of ZnO Nps was confirmed by surface morphology from SEM and surface topography of AFM. The PZ3-PA membrane exhibited remarkable water flux of 7.64 L/m²h for 3 days of operation time under the presence of humic acid, crude oil, and SDS as fouling agent, and high salt rejection which is almost 100%. Therefore, omniphobic surface modification with the combination of ZnO Nps and palmitic acid is very promising, as it imparts excellent anti-wetting properties and desalination performance.

Efficiency of drilling fluid is the foremost step in the success of any drilling activity. Real-time surveillance of the properties of a drilling mud significantly impacts the efficiency and wellbore integrity. In this article, a crystal structure of TiO₂ explicitly rutile was composited with multi-walled carbon nanotubes (MWCNTs). The limitations associated with TiO₂ and MWCNTs such as high energy gap, rapid kinetics, agglomeration and dispersion substantially reduces once they are linked together, which eventually impacts the stability and properties of drilling fluid. Nevertheless, the specific crystal structure of TiO₂ demonstrates inherent shortcoming stemming from its structural characteristics. To test the efficacy of the particles in the drilling mud, five mud samples with concentration of nanoparticles ranges between 0.35 and 3.5 g were prepared and investigated for the shale stability. These five samples were tested on the most problematic Ranikot shale gathered deep down from the Indus Basin. Excessive moisture content in the shale was the main factor that contributes heavily to the severe wellbore instability issues. According to the study results, it was observed that MWCNTs/rutile-TiO₂ exhibited higher fluid loss volume. Moreover, MWCNTs/rutile-TiO₂ mud started to dephase at a rapid pace, and completely loses its stability within 6 h of experimentation. The crystal structure of rutile, specifically its large grain size and low porosity, contribute to a decrease in surface area, thereby destabilizing the system. Furthermore, when the Ranikot shale pellets were exposed to MWCNTs/rutile-TiO₂ mud in immersion testing, they were either completely broken down in pieces or suffered significantly from cracks and fracture. In addition, sample in linear dynamic swell meter also demonstrated high water intake with higher swelling behavior of 14.1% after 24 h. Also, the shale dissolved point was achieved at the 16 h of experiment. An earlier shale dissolved point will create problems like stuck pipe, caving, washouts and high cutting concentration within the wellbore. This will eventually impact the equivalent circulating density within the borehole.

In this contribution, a simple and fast method for the synthesis of various types of benzothiazoles, benzoxazoles, and benzo[1,3]-dithioles using Ullman coupling reaction of dihalobenzene and nitro-heterocumulene compounds in the vicinity of copper catalyst, Cs₂CO₃ as the base, and highly efficient was successfully implemented without the help of an additional ligand under ultrasound irradiation. The use of simple and readily available starting materials, mild copper-catalytic reaction conditions, no column chromatography, good yields, applying the sonochemical methodology, and short reaction times are remarkable specifications of this protocol.

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Understanding molecular interactions is essential for biologists to elucidate protein functions, behaviors, and predict related biological processes. Recent studies have concentrated on examining protein–nanoparticle interactions using various techniques to determine the biological effects of nanoparticles. Investigating dendrimers as potential drug delivery agents requires an understanding of their ability to bind small ligands. In this research, we thoroughly examined the interaction between human serum albumin (HSA) and biocompatible polymeric Phloroglucinol Succinic Acid (PGSA) dendrimers of different generations. Using spectroscopic analysis and molecular docking studies, we aimed to uncover the mechanisms behind PGSA dendrimer-HSA binding, which could enhance stability, half-life, and bio-distribution. Our results, obtained through UV-Visible spectroscopy, fluorescence spectroscopy, and molecular docking, indicate a predominantly ground state complex formation with a single binding site, mainly mediated by hydrogen bonding. This study highlights the importance of understanding polymeric nanoparticle–protein interactions in drug design to improve drug solubility and therapeutic efficacy. Additionally, our investigation into dendrimer-HSA interactions offers promising insights into bio-barrier permeability, potentially aiding in the treatment of brain tumors using dendritic structures.

The kinetics and mechanism of methane CH₄ reaction with chlorine Cl atoms have been previously investigated using quantum theoretical calculations. In this study, we have investigated the hydrogen abstraction reaction by DFT using the CBS-QB3 method. Moreover, we have employed the Rice-Ramsperger-Kassel-Marcus theory to compute the rate constants of the reaction at a pressure of 1 atm and in the 295–1104 K temperature range. This study offers for the first time the theoretical mechanism and kinetic determination of the CH₄ + Cl reaction, over a wide temperature interval, as well as its importance in the halogenation reaction. The obtained rate constant was found to be k(T) = 7.29 × 10^‒19 × exp(‒287.65/T) cm³.molecule^‒1.s^‒1 and is in reasonable accord with that observed for C_xH_yCl, both theoretically and experimentally.

This study presents the fabrication and characterization of an Al(III) ion-selective electrode (ISE) using a novel BN@SnP composite. The composite, synthesized through a sol–gel process, integrates boron nitride (BN) nanoparticles into tin phosphate precipitates, exhibiting enhanced ion exchange capacity compared to individual inorganic counterparts. The resulting ion exchanger demonstrates selectivity towards Al (III) ions, forming the basis for constructing an ISE. The fabricated electrode exhibits a rapid response time of 10 s, a Nernstian slope of 22.05 mV decade⁻¹, and a wide linear range spanning from 1.0 × 10⁻⁷ to 1.0 × 10⁻¹ M. The electrode demonstrates a low limit of detection (LOD) of 7.5 × 10 ⁻⁸M, highlighting its high sensitivity. The composite’s selectivity for Al (III) ions is confirmed through distribution coefficient studies, showcasing its preference over various metal ions. The chosen membrane for the electrode, M-3, exhibits optimal characteristics, including ideal thickness, high water content, and porosity. Comparative analysis with reported electrodes underscores the competitive performance of the proposed electrode. This research introduces a proficient ISE for Al (III) detection and sets the stage for future explorations in composite materials and their applications in biomedical monitoring, such as tracking aluminium levels in biological fluids for early diagnosis and management of neurological disorders, and environmental monitoring and analytical chemistry.

A new procedure that is free of copper and palladium has been developed for the sequential synthesis of 3,5-disubstituted-1H-pyrazoles using various N-acylbenzotriazoles, terminal alkynes, and hydrazine. In this process, N-acylbenzotriazoles react with terminal alkynes in 1-butyl-3-methyl-imidazolium tetrafluoroborate, catalyzed by zinc chloride, to produce α,β-unsaturated alkynones. These intermediates are then converted into pyrazoles through an in-situ reaction with hydrazine. Additionally, the ionic liquid can be recovered and reused without significant loss of efficiency.

Disrupted redox homeostasis and elevated ROS levels are linked to various diseases, including cancer and neurodegenerative disorders. MutT homolog 1 (MTH1) is a critical enzyme that protects against oxidative DNA damage by eliminating oxidized dNTPs. This study explored MTH1 as a drug target, screened 18,000 natural compounds from the IMMPAT library using structure-based drug design approaches. The most suitable candidates were identified through a rigorous process that included physicochemical and pharmacokinetic profiling, pan-assay interference compounds, and prediction of activity spectra for substances analysis (PASS). This screening process, designed to ensure the selection of most promising compounds, that were Vinburnine and Norstephalagine. These molecules demonstrated high binding affinity for MTH1 and exhibited favorable pharmacokinetic properties based on ADMET and PASS analyses. Detailed interaction analysis revealed that both Vinburnine and Norstephalagine effectively occupy the binding pocket of MTH1, engaging with its active site residues. Further molecular dynamics simulations confirmed the stability of the MTH1-Vinburnine and MTH1-Norstephalagine complexes, showing minimal structural deviations from the native MTH1 enzyme. This study also employed BAY-707 as a positive control and CID:11150163 as a negative control to validate the binding affinities and interaction profiles of the identified hits. In conclusion, our study identified Vinburnine and Norstephalagine as potent MTH1 inhibitors with significant potential for therapeutic development against cancer and other diseases associated with MTH1 dysfunction. These findings highlight these compounds as promising therapeutic candidates and provide a foundation for the rational design of future MTH1 inhibitors for the therapeutic targeting of cancer and neurodegenerative diseases.

Non-covalent organic heterosynthons show enhanced properties in contrast to their individual coformers, rendering them promising for various applications. Specifically, hydrogen-bonded heterosynthons have shown effective coordination behavior with diverse metal ions, hinting at their potential for rapid optical sensing. Their straightforward synthesis and the interactions between the coformers make them good candidates for detection purposes. While organic acid derivatives are well known for their effectiveness as potential sensing agents toward different water pollutants, there remains a significant gap in the literature regarding the efficiency of heterosynthons linked via hydrogen bonding in colorimetric sensing applications, particularly for metal ions in aqueous environmental matrices. Therefore, in this study, five hydrogen-bonded heterosynthons, phthalic acid/2-amino-3-methylpyridine 1, phthalic acid/imidazole 2, dipicolinic acid/pyrazole 3, dipicolinic acid/imidazole 4, and dipicolinic acid/2-amino-3-methylpyridine 5 of two distinct dicarboxylic acids were synthesized using slow evaporation method and characterized using FT-IR, UV–Vis, ¹H-NMR, and PXRD spectroscopic techniques. Physical mixtures with different molar ratios using the same coformers were prepared through a grinding method. Binary phase diagrams were constructed, and FT-IR analysis was performed to propose the type of heterosynthons being formed. The colorimetric detection efficiency of the synthesized heterosynthons toward a wide range of metal ions was examined and compared to that of their individual acids. Interestingly, all heterosynthons demonstrated enhanced colorimetric sensing performance toward metal ions. However, dipicolinic acid/pyrazole 3 and dipicolinic acid/2-amino-3-methylpyridine 5 did not show any significant color change in the presence of Ni(II) in contrast to the pure acid. This could be enhanced by improving the structural conjugation of the prepared heterosynthons and accordingly intensifying the obtained color and enhancing the naked-eye colorimetric detection results.

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The phenomenon of fertilizer caking has an impact on the commercial value of the final products. It can occur throughout the life cycle, including production, storage, transport and final agricultural application. Fertilizer caking leads to clumping and agglomeration and presents a significant challenge. This review comprehensively examines the mechanisms underlying granular fertilizer caking, focusing on the complex interactions at the granular level, particularly adhesive and phase contacts. These interactions, including solid–solid and solid–liquid contacts, are pivotal in the agglomeration process, with salt bridges from phase contacts being a critical factor in caking propensity. The review identifies numerous factors influencing fertilizer caking. Internal factors such as chemical composition, particle size, hardness, and moisture content, as well as external factors like weather fluctuations, pressure, storage duration, and the effectiveness of coating agents, profoundly affect caking behavior. By synthesizing existing literature, this work provides valuable insights into the multifaceted nature of granular fertilizer caking, elucidating the underlying mechanisms and factors involved. This review lays the groundwork for future research aimed at mitigating caking challenges in fertilizer production and storage.