Traces Of Water Research Articles

Synergistically enhanced water-resistive perovskite nanocrystals for cell nucleus imaging and acid phosphatase detection

Despite the impressive success of metal halide perovskite nanocrystals (NCs) in diverse fields, such as solar cells, light-emitting diodes, photodetectors, and so forth, their intrinsic sensitivity to water limits the extending applications in aqueous systems. Herein, enhanced water stability is achieved for NH2-PEG-COOH capped Mn2+-doped CsPbCl3/CsPb2Cl5 core/shell NCs through the synergistic effect of ion doping, core/shell construction and polymer encapsulation. The NH2-PEG-COOH encapsulation is validated crucial for the formation of CsPbCl3/CsPb2Cl5 core/shell structure, since it retains contact for CsPbCl3 NCs with trace water, and guarantees a slow water-etching process, triggering the CsPbCl3 to CsPb2Cl5 transformation. Thanks to the high formation energy induced by Mn2+ doping, CsPbCl3/CsPb2Cl5 hetero core/shell construction and NH2-PEG-COOH protective barrier, the obtained NCs exhibit unattenuated photoluminescence quantum yield after dipped in water for 15 days. Based on the robust water stability, the NH2-PEG-COOH capped Mn2+-doped CsPbCl3/CsPb2Cl5 NCs work well in cell nucleus imaging and acid phosphatase detection. This work not only produces a novel perovskite fluorescence probe in aqueous systems but also provides a general and effective combination strategy to enhance the water stability of perovskite materials.

Characterization of a Simulated Martian Regolith Ecosystem by Proton Nuclear Magnetic Resonance (NMR) Relaxometry and Fourier Transform Infrared (FT-IR) and Visible (VIS)-Near-Infrared (NIR) Spectroscopies

Of the various Martian soil simulant mixes developed by NASA and Jet Propulsion Laboratory (JPL), three types were chosen that have the closest features to those of the Martian regolith to be analyzed. The characterization of the Martian regolith types was performed the advanced methods of 1H nuclear magnetic resonance (NMR) relaxometry, Fourier transform infrared (FT-IR) spectroscopy and visible (VIS)-near-infrared (NIR) spectroscopy, as well as classical methods such as pH, the electrical conductivity, and the total dissolved solids. These analyses showed that trace water, nitrogen, phosphorus and potassium are present in the Martian regolith simulant. A Martian Garden has been built with the Martian soils, in which various vegetables have been seeded. Among the Fourier Transform infrared (FT-IR) spectra acquired for the plants, a high degree of similarity was observed, which indicates that the substrate ‘Martian regolith simulant of terrestrial soil’ does not significantly influence the structure of the radish, peas and bean leaves, stems, or roots. Nevertheless, the results of 1D 1H nuclear magnetic resonance (NMR) relaxometry indicate that the substrate presents a high influence on the water dynamics in plant pores at the level of roots, stems and leaves and in bound water. A Marsarium was designed and built, where all types of Martian and terrestrial soils were introduced, together with a family of ants. The ants adapted to the imposed conditions, as they dug tunnels in the soils.

Multi-stimuli-responsive cyanostilbene derivatives: Their fluorescent and mechanochromic properties, and potential application in water sensing and anti-counterfeiting

In recent years, aggregation-induced emission luminogens (AIEgens) have witnessed numerous groundbreaking advances in fundamental theoretical research and functional applications. Notably, stimuli-responsive AIEgens have achieved remarkable results, demonstrating immense potential for application in various fields such as chemistry, materials science, biology, and medicine. Herein, two multi-stimuli-responsive cyanostilbene derivatives TPE-CNTPA and PH-CNTPA were synthesized by introducing tetraphenylethylene (TPE) and trifluoromethyl groups, respectively. Primarily, under the combined mechanism of aggregation-induced emission (AIE) and twisted intramolecular charge transfer (TICT), TPE-CNTPA and PH-CNTPA exhibit “on-off-on” fluorescent emission characteristics in solution. Secondly, under 365 nm ultraviolet light irradiation, the photo-induced isomerization of PH-CNTPA causes changes in photophysical property, demonstrating its responsiveness to ultraviolet light. In addition, TPE-CNTPA and PH-CNTPA exhibit high-contrast mechanochromic properties, providing broader possibilities for their potential applications in various fields. Moreover, owing to the unique fluorescence emission characteristics, TPE-CNTPA and PH-CNTP have enormous potential for application in the field of encryption anti-counterfeiting. Besides, PH-CNTPA can be utilized for the detection of trace water in single or mixed solvents, demonstrating outstanding sensitivity and anti-interference properties in different solvents. This research work reveals the potential in the fields of water sensing and anti-counterfeiting for these two multi-stimuli-responsive compounds.

Fluorion-deprotonated fluorescent sensor for the highly sensitivity detection of trace water in chemical reagents and application in inkless writing

A simple diphenylimidazole-based colorimetric and fluorescent sensor (DIB) was successfully synthesized by one step reaction. DIB exhibited excellent selectivity and sensitivity for F- over various other anions with fluorescence enhancement effect. The limit of detection of DIB towards F- was evaluated to be 9.18 × 10-8 M. A plausible sensing mechanism of DIB towards F- had been proposed on the basis of spectral analysis and 1H NMR titration experiments, which the results suggested that the recognition process could be attributed to the deprotonation of imidazole group. Interestingly, the F- induced deprotonation system of DIB·F could be employed as reversible sensor for trace water with high sensitivity and instant response. The color change easily recognized by the naked eye and low limit of detection (0.0022 %) improved the detection performance of DIB·F for water. Importantly, the DIB·F system had been successfully applied for the quantitative analysis of water content in experimental chemical reagents. In addition, sensor DIB and DIB·F-incorporated filter papers could be utilized as inkless writing display device for F- and water detection, respectively, with reusability.

A novel fluorescent indicator-based fluorene derivative for rapid and visual trace water sensing.

Fluorene nucleus derivatives show great potential for building outstanding fluorescence probes. In this paper, a novel fluorescent probe was developed by reacting with fluorene core with azacyclobutane, which exhibits typical solvation chromogenic effect in solvent. The fluorescence of the probe quenched in highly polar solvent. Based on this phenomenon, a novel fluorescence system for trace water was constructed. The response of this probe was fast (30 s) and sensitive for the detection of trace water in organic solvents, and the detection limit of water content in DMSO reached 0.13%. In addition, the probe can also be made as a test strip combined with homemade portable device and a smartphone for rapid detection of trace water. The luminescence mechanism of the probe is theoretically calculated based on time-contained density functional theory (TDDFT). To showcase its practicality, it has been applied for the detection of trace water in honey and alcohol by dipstick. This method provides a new idea for designing efficient fluorescent probes based on dipstick and mobile phone rapid detection.

Detecting clusters and tracing management of water distribution system using space–time scan statistics and utility network modeling

Water-quality incidents in the water supply can occur because of errors in pressurization plant operations, leaks, and pollutant infiltration. They lead to citizen complaints about water quality. Identifying high-risk areas and contributing factors for accidents helps to prevent incidents. Here, a predictive analysis technique based on a geographic information system and complaint data was developed using SaTScan, a space–time statistical analysis program. High-risk clusters were identified using maximum log-likelihood ratios, relative risks, and Monte Carlo hypothesis testing. After a red water accident, high-risk clusters (C6–C9) were concentrated in one area. The relative risk of C7 before the accident was 4.58, double that of C2 (2.21). Using ArcGIS, a utility network dataset was created for the water-supply infrastructure in the high-risk cluster area. A utility network model enables flow simulation of the target water supply and tracing of the scope of influence. Downstream analysis of the trace showed that C8 had the greatest expected range of damage following an accident. To address this issue, four valves requiring controls were identified. C6 was predicted to suffer the most significant damage in an accident because it was closest to the water purification plant and had the largest pipe diameter.

Photoacoustic Spectroscopy Using a Quantum Cascade Laser for Analysis of Ammonia in Water Solutions.

Ammonia (NH3) toxicity, stemming from nitrification, can adversely affect aquatic life and influence the taste and odor of drinking water. This underscores the necessity for highly responsive and accurate sensors to continuously monitor NH3 levels in water, especially in complex environments, where reliable sensors have been lacking until this point. Herein, we detail the development of a sensor comprising a compact and selective analyzer with low gas consumption and a timely response based on photoacoustic spectroscopy. This, combined with an automated liquid sampling system, enables the precise detection of ammonia traces in water. The sensor system incorporates a state-of-the art quantum cascade laser as the excitation source emitting at 9 μm in resonance with the absorption line of NH3 located at 1103.46 cm-1. Our instrument demonstrated detection sensitivity at a low ppm level for the ammonia molecule with response times of less than 60 s. For the sampling system, an ammonia stripping solution was designed, resulting in a prompt full measurement cycle (6.35 min). A further evaluation of the sensor within a pilot study showed good reliability and agreement with the reference method for real water samples, confirming the potential of our NH3 analyzer for water quality monitoring applications.

Late-Stage Saturation of Drug Molecules.

The available methods of chemical synthesis have arguably contributed to the prevalence of aromatic rings, such as benzene, toluene, xylene, or pyridine, in modern pharmaceuticals. Many such sp2-carbon-rich fragments are now easy to synthesize using high-quality cross-coupling reactions that click together an ever-expanding menu of commercially available building blocks, but the products are flat and lipophilic, decreasing their odds of becoming marketed drugs. Converting flat aromatic molecules into saturated analogues with a higher fraction of sp3 carbons could improve their medicinal properties and facilitate the invention of safe, efficacious, metabolically stable, and soluble medicines. In this study, we show that aromatic and heteroaromatic drugs can be readily saturated under exceptionally mild rhodium-catalyzed hydrogenation, acid-mediated reduction, or photocatalyzed-hydrogenation conditions, converting sp2 carbon atoms into sp3 carbon atoms and leading to saturated molecules with improved medicinal properties. These methods are productive in diverse pockets of chemical space, producing complex saturated pharmaceuticals bearing a variety of functional groups and three-dimensional architectures. The rhodium-catalyzed method tolerates traces of dimethyl sulfoxide (DMSO) or water, meaning that pharmaceutical compound collections, which are typically stored in wet DMSO, can finally be reformatted for use as substrates for chemical synthesis. This latter application is demonstrated through the late-stage saturation (LSS) of 768 complex and densely functionalized small-molecule drugs.

Eliminating H2O/HF and regulating interphase with bifunctional tolylene-2, 4-diisocyanate (TDI) additive for long life Li-ion battery

Lithium-ion batteries (LIBs) featuring a Ni-rich cathode exhibit increased specific capacity, but the establishment of a stable interphase through the implementation of a functional electrolyte strategy remains challenging. Especially when the battery is operated under high temperature, the trace water present in the electrolyte will accelerate the hydrolysis of the electrolyte and the resulting HF will further erode the interphase. In order to enhance the long-term cycling performance of graphite/LiNi0.8Co0.1Mn0.1O2 (NCM811) LIBs, herein, Tolylene-2,4-diisocyanate (TDI) additive containing lone-pair electrons is employed to formulate a novel bifunctional electrolyte aimed at eliminating H2O/HF generated at elevated temperature. After 1000 cycles at 25 °C, the battery incorporating the TDI-containing electrolyte exhibits an impressive capacity retention of 94% at 1 C. In contrast, the battery utilizing the blank electrolyte has a lower capacity retention of only 78%. Furthermore, after undergoing 550 cycles at 1 C under 45 °C, the inclusion of TDI results in a notable enhancement of capacity, increasing it from 68% to 80%. This indicates TDI has a favorable influence on the cycling performance of LIBs, especially at elevated temperatures. The analysis of the film formation mechanism suggests that the lone pair of electrons of the isocyanate group in TDI play a crucial role in inhibiting the generation of H2O and HF, which leads to the formation of a thin and dense interphase. The existence of this interphase is thought to substantially enhance the cycling performance of the LIBs. This work not only improves the performance of graphite/NCM811 batteries at room temperature and high temperature by eliminating H2O/HF but also presents a novel strategy for advancing functional electrolyte development.

Influence of water on the properties of hydrophobic deep eutectic solvent

Deep eutectic solvent (DES) shows excellent absorption performance in the field of CO2 capture. It is considered as a new green absorption solvent to replace monoethanolamine. In the industry, the presence of water not only affects the structural stability of the solvent, but also affects its thermophysical properties. In this work, three kinds of hydrophobic DES were prepared. Based on the study of their structural characteristics and thermal stability, the density and viscosity of DES with water mixture were measured in the temperature range of 298.15 ∼ 338.15 K at atmospheric pressure. It was demonstrated that the trace water did not destroy the structure of DES, but it formed hydrogen bonds with DES. The increase water destroyed the structure of DES and formed hydrogen bonds with hydrogen bond donor (HBD) and hydrogen bond acceptor (HBA), respectively. Moreover, the hard sphere model was applied to study the viscosity, and after introducing the binary interaction parameter, the average absolute relative deviation of the mixture reduced to 4.4 ∼ 7.7 %.

Tracking and tracing water consumption for informed water sensitive intervention through machine learning approach

To develop a water conscious strategy, it is critical to track and trace water from its source to the end users, understand water conservation behaviors, and identify the factors that influence water consumption. However, in developing nations, little research has been done to provide a quantitative picture of how water is consumed and transformed in urban households, as well as the water sensitive interventions needed to improve access to clean water. Hence, the main objective of the study was to determine the most significant residential water consumption variables and to predict residential water consumption in a way that can generate water consumption information for water sensitive intervention decision making using the case study of Adama city in Ethiopia. A combination of top down and bottom up data collection techniques were employed as the data collection instrument. Machine learning was integrated with spatial and socioeconomic analytic techniques to estimate daily household water consumption and identify the factors that significantly influence household water consumption. The results show that there is only “one source option” for the city’s clean water supply and that different water harvesting methods are not likely to be developed. The average daily water consumption per person is 69 liters which falls below the national standard of 80 liters allocated per person per day. The result reveals that the water distribution network covers only 45% of the city master plan. About 38% of the water demand is unmet and 30% of households only receive water once every three days or fewer. This shows that the city is experiencing physical and economic water scarcity. The results demonstrated that family size, housing quality, income, number of rooms, legal status of the parcel, supply reliability, climate, and topographical features are the most important factors in predicting residential water consumption. This study further demonstrates how well supervised machine learning models, such as the Random Forest Regression algorithm, can predict the household’s daily water consumption. The findings also showed that there is a need for significant improvements in water saving habits of the households. Another conclusion that can be drawn is that as long as the city’s business as usual water consumption practice doesn’t change, the water supply problem will worsen over time.

Comparative analysis of tracer studies in the determination of longitudinal dispersion coefficient.

The research presented in this paper is to determine the best tracer studies that will give acceptable estimates of longitudinal dispersion coefficient for Orashi river using rhodamine WT dye and sodium chloride as water tracer. Estimated results obtained for longitudinal dispersion coefficient for the case of rhodamine WT experiment ranges between 71 and 104.4 m2s-1 while that of sodium chloride experiment ranges between 20.1 and 34.71 m2s-1. These results revealed lower dispersion coefficient using sodium chloride as water tracer (WT) indicating that for larger rivers, sodium chloride should not be used as water tracer. The usage of sodium chloride as water tracer in the estimation of longitudinal dispersion coefficient is recommended in smaller streams as NaCl is relatively conservative. The established equations for both cases of investigation are proving satisfactory upon validation as degree of accuracy of 100.0% was obtained using discrepancy ratio (Dr). Standard error (SE), normal mean error (NME) and mean multiplication error (MME) of the developed equations is better when compared with other existing equations. However, Equation (17) is satisfactorily recommended.

Enhancing compatibility between LiNi0.8Co0.1Mn0.1O2 and LiPF6-based electrolyte via bis(trimethylsilyl)oxalate additive

LiNi0.8Co0.1Mn0.1O2 (NCM811)-layered oxide has a high discharge capacity and is considered as an alternative cathode for next-generation high-energy density lithium-ion batteries (LIBs). However, the corrosion of LiPF6-based electrolyte and the poor stability of the cathode solid electrolyte interface (CEI) film pose a threat to the cyclic stability of the battery. Herein, bis(trimethylsilyl)oxalate (DTMSO) is introduced as a novel multifunctional electrolyte additive to construct a stable CEI film and improve the high temperature tolerance of NCM811/Li cells. Results show that DTMSO can effectively scavenge HF resulted from trace water and high temperature, preventing the detrimental effects of HF on CEI film and NCM811 electrode material. More than that, DTMSO can react with LiPF6 to form conducive lithium tetrafluoro(oxalate)phosphate (LiTFOP) when undergoes the ordeal of high temperature (55 °C) for 24 h. The as-generated LiTFOP aids in the construction of a stable and conductive CEI film that is rich in LiF and LixPOyFz. Benefit from these characteristics, DTMSO additive enables effective protection of the electrode material and mitigates capacity decay in the battery, ultimately facilitating good cycling performance and improving ability to resist high temperature within a certain time. As a result, the capacity retention rate of the NCM811/Li cell after 100 cycles is increased from 67.8% to 85.6%, when the test condition is shelved at 55 °C for 24 h and then changed back to cycling at 25 °C. This work provides a viable strategy for the development of electrolytes compatible with nickel-rich cathode and is of great significance for the development of advanced LIBs.

Deciphering the Microdroplet Acceleration Factors of Aza-Michael Addition Reactions.

Microdroplet chemistry is emerging as a great tool for accelerating reactions by several orders of magnitude. Several unique properties such as extreme pHs, interfacial electric fields (IEFs), and partial solvation have been reported to be responsible for the acceleration; however, which factor plays the key role remains elusive. Here, we performed quantum chemical calculations to explore the underlying mechanisms of an aza-Michael addition reaction between methylamine and acrylamide. We showed that the acceleration in methanol microdroplets results from the cumulative effects of several factors. The acidic surface of the microdroplet plays a dominating role, leading to a decrease of ∼9 kcal/mol in the activation barrier. We speculated that the dissociation of both methanol and trace water contributes to the surface acidity. An IEF of 0.1 V/Å can further decrease the barrier by ∼2 kcal/mol. Partial solvation has a negligible effect on lowering the activation barrier in microdroplets but can increase the collision frequency between reactants. With acidity revealed to be the major accelerating factor for methanol droplets, reactions on water microdroplets should have even higher rates because water is more acidic. Both theoretically and experimentally, we confirmed that water microdroplets significantly accelerate the aza-Michael reaction, achieving an acceleration factor that exceeds 107. This work elucidates the multifactorial influences on the microdroplet acceleration mechanism, and with such detailed mechanistic investigations, we anticipate that microdroplet chemistry will be an avenue rich in opportunities in the realm of green synthesis.

A stable Zr(IV)-MOF for efficient removal of trace SO2 from flue gas in dry and humid conditions

Obtaining suitable adsorbents for selective separation of SO2 from flue gas still remains an important issue. A stable Zr(IV)-MOF (Zr-PTBA) can be conveniently synthesized through the self-assembly of a tetracarboxylic acid ligand (H4L = 4,4',4'',4'''-(1,4-phenylenebis(azanetriyl))tetrabenzoic acid) and ZrCl4 in the presence of trace water. It exhibits a three-dimensional porous structure. The BET surface area is 1112.72 m2/g and the average pore size distribution focus on 5.9, 8.0 and 9.3 Å. Interestingly, Zr-PTBA shows selective adsorption of SO2. The maximum uptake reaches 223.21 cm3/g at ambient condition. While it exhibits lower adsorption uptake of CO2 (30.50 cm3/g) and hardly adsorbs O2 (2.57 cm3/g) and N2 (1.31 cm3/g). Higher IAST selectivities of SO2/CO2 (21.9), SO2/N2 (912.7), SO2/O2 (2269.9) and SO2/CH4 (85.0) have been obtained, which reveal its’ excellent gas separation performance. Breakthrough experiment further confirms its application for flue gas deep desulfurization both in dry and humid conditions. Furthermore, the gas adsorption results and mechanisms have also been studied by theoretical calculations.

Analysis of frost layer growth behavior on cryogenic surfaces in ultralow dew point environments by experimental tests and numerical simulations

Maintaining an ultralow dew point is essential for the operation of transonic cryogenic wind tunnels, as it significantly influences aerodynamic characteristics. Even in extremely dry conditions, minute quantities of frost can form on cryogenic surfaces, which compromises data quality. Conducting experiments on frost desublimation in such ultralow dew point environments poses significant challenges due to the demanding experimental conditions. Therefore, this study aimed to explore the desublimation characteristics of cryogenic surfaces in ultralow dew point environments and to address the challenges of experimental investigations under such extreme conditions. Initially, the study experimentally investigated frost formation by assessing the impact of various factors, such as temperature and water vapor content. It was observed that the type of frost formed depended on the water vapor content, and altering the surface temperature influenced the growth region of the frost crystals. The irregular growth of the frost layer on low-temperature surfaces was evident, as temperature markedly affected both the growth rate and the diffusion direction of frost formation. Moreover, the process of trace water frost formation was simulated using a dispersive multiphase model, predicting the frost layer's thickness. The numerical results suggest that the frost layer is micrometers thick, with a minimum thickness of 20 μm. A nonlinear relationship was identified between frost growth and dew point level. This research lays the groundwork for a deeper understanding of desublimation characteristics in ultralow dew point environments and for further investigation of low-temperature heat and mass transfer phenomena.

Macromers for Encapsulating Perovskite Photovoltaics and Achieving High Stability.

Perovskite solar cells (pero-SCs) are highly unstable even under trace water. Although the blanket encapsulation (BE) strategy applied in the industry can effectively block moisture invasion, the commercial UV-curable adhesives (UVCAs) for BE still trigger power conversion efficiency deterioration, and the degradation mechanism remains unknown. For the first time, the functions of commercial UVCAs are revealed in BE-processed pero-SCs, where the small-sized monomer easily permeates to the perovskite surface, forming an insulating barrier to block charge extraction, while the high-polarity moiety can destroy perovskite lattice. To solve these problems, a macromer, named PIBA is carefully designed, by grafting two acrylate terminal groups on the highly gastight polyisobutylene and realizes an increased molecular diameter as well as avoided high-polarity groups. The PIBA macromer can stabilize on pero-SCs and then sufficiently crosslink, forming a compact and stable network under UV light without sacrificing device performance during the BE process. The resultant BE devices show negligible efficiency loss after storage at 85% relative humidity for 2000h. More importantly, these devices can even reach ISO 20653:2013 Degrees of protection IPX7 standard when immersed in one-meter-deep water. This BE strategy shows good universality in enhancing the moisture stability of pero-SCs, irrespective of the perovskite composition or device structure.

Valorisation of biogas for market development and remission of environmental nuisance in Uganda

In Uganda, biogas is a low-value product considered a pro-poor renewable energy source. Farmers with excess biogas release it into the atmosphere, contributing to global warming. This study used mixed data sources and methods to explore how biogas can be valorised to become a valued commercial energy source in Uganda and reduce greenhouse gas emissions. The results reveal the inefficiency of current biogas purification processes: the concentration of methane (CH4) in the upgraded gas was only 58 %, far below the standard specification of 98 %. The pilot production process never came close to even the lower specification level of 95 % for upgraded methane and the upper specification level of 5 % for carbon dioxide (CO2). The presence of traces of H2S, water and oxygen could lead to the corrosion of storage equipment and complicate the use of the gas. The study also found that small-scale biogas producers with excess gas have a high desire to sell it but have currently no clear idea of how to valorise it to reach the market. Our market analysis revealed three promising customer segments: bioenergy entrepreneurs, gas companies and electricity suppliers. Taken together, our findings imply that to become a commercially viable energy source, the quality of biogas needs to be improved using valorisation strategies like monitoring gas quality, shaping the market, market research and certification and controls. The national bioenergy policy could consider subsidising valorisation technologies to make them affordable for farmers and thus support a more climate-smart biogas commercialisation process.

Study on the Adsorption of Trace Water in N-Methyl-pyrrolidone Solvents by A-Type Molecular Sieves.

N-Methyl-pyrrolidone (NMP) is an important coating solvent for the production of lithium batteries, and its water content will greatly affect the coating quality and energy density of lithium batteries, which needs to be reduced to 200 ppm. The current vacuum distillation technology suffers from high operating costs and high energy consumption, whereas the pervaporation technology only achieves solvent dehydration up to 99.5%. Therefore, it is of great significance to carry out the study of trace water removal from NMP solvents. In this paper, the A-type molecular sieve adsorption method was used to remove trace water from the NMP solvent, and the effects of molecular sieve type, particle size, adsorption temperature, feeding amount, and contact time on the dehydration performance of NMP system were first investigated. Adsorbed at 25 °C for 240 min at a feeding amount of 120 g/L, 3A molecular sieves were able to reduce the water content of the NMP solvent from 5000 to 140 ppm. Second, Langmuir and Freundlich equations were used to fit the static isothermal adsorption data, and the results showed a better correlation of the Langmuir equation. Then, the adsorption kinetics and diffusion mechanism were analyzed by the kinetic model and the Crank single-pore diffusion model. The R2 of the pseudo-first-order kinetic model was 0.9993, which was more suitable for describing the process of adsorption of water from the NMP solvent by 3A molecular sieves, and the effective diffusion coefficient De = 2.986 × 10-8 cm2/s was calculated for the Crank single-pore adsorption model, which proved water molecules on the 3A molecular sieve. The diffusion of water molecules on the inner surface of the pores is the controlling step of the adsorption process. Finally, the fixed-bed dynamic penetration curves were investigated to obtain the experimental data of fixed-bed adsorption, and the experimental data were fitted using the Thomas and Yoon-Nelson models, which showed that both models could describe the adsorption behavior of trace water in NMP solvents on 3A molecular sieves. This study provides a new idea for the removal of trace water in NMP systems, and a series of model fitting parameters provide basic data for industrial scale-up.

Lead-Free Antimony-Based Perovskite Nanocrystals as a Fluorescent Nanoprobe for the Turn-On Detection of Trace Water in Organic Solvents

Lead-Free Antimony-Based Perovskite Nanocrystals as a Fluorescent Nanoprobe for the Turn-On Detection of Trace Water in Organic Solvents