Mechanochemical Recycling of Flexible Polyurethane Foam Scraps for Quantitative Replacement of Polyol Using Wedge-Block-Reinforced Extruder.

Recycling flexible polyurethane foam (F-PUF) scraps is difficult due to the material's high cross-linking structure. In this work, a wedge-block-reinforced extruder with a considerable enhanced shear extrusion and stretching area between the rotating screw and the stationary wedge blocks was utilized to recycle F-PUF scraps into powder containing surface-active hydroxyl groups. The powder was then utilized for the quantitative replacement of polyol in the foaming process. Characterizations showed that the continuous shear extrusion and stretching during the extrusion process reduced the volume mean diameter (VMD) of the F-PUF powder obtained by extruding it three times at room temperature to reach 54 µm. The -OH number (OHN) of the powder prepared by extruding it three times reached 19.51 mgKOH/g due to the mechanochemical effect of the powdering method. The F-PUF containing recycled powder used to quantitively replace 10 wt.% polyol was similar in microstructure and chemical structure to the original F-PUF, with a compression set of 2%, indentation load deflection of 21.3 lbf, resilience of 43.4%, air permeability of 815.7 L/m2·s, tensile strength of 73.0 Kpa, and tear strength of 2.3 N/cm, indicating that the recycling method has potential for industrial applications.

Advanced Materials for NH3 Capture: Interaction Sites and Transport Pathways.

Ammonia (NH3) is a carbon-free, hydrogen-rich chemical related to global food safety, clean energy, and environmental protection. As an essential technology for meeting the requirements raised by such issues, NH3 capture has been intensively explored by researchers in both fundamental and applied fields. The four typical methods used are (1) solvent absorption by ionic liquids and their derivatives, (2) adsorption by porous solids, (3) ab-adsorption by porous liquids, and (4) membrane separation. Rooted in the development of advanced materials for NH3 capture, we conducted a coherent review of the design of different materials, mainly in the past 5 years, their interactions with NH3 molecules and construction of transport pathways, as well as the structure-property relationship, with specific examples discussed. Finally, the challenges in current research and future worthwhile directions for NH3 capture materials are proposed.

Zr modulated N doping composites for CO2 conversion into carbonates.

Acidic and basic sites of catalysts are essential for CO2 capture and activation. In this work, Zr, N-ZnO/ZnAl-LDH-IL composites in ionic liquid and methanol systems were fabricated, and applied to catalyze the synthesis of ethylene carbonate (EC) from ethylene glycol (EG) and CO2 with about 4.76 mmolEC gCat.-1 h-1. The composites showed more strong basic sites due to the effective induction of reactive groups on the catalyst surface by Zr doping, resulting in an increase of pyridinic-N groups from 5.48% to 22.25%. More C atoms adjacent to pyridinic-N as strong basic sites was conducive to the activation of CO2 and EG. In addition, the possible catalytic pathway and mechanism of the composites for synthesizing EC as well as the doping of La, Fe, Ce, and Cu were also investigated, which provides an effective strategy for regulating the acid-base centers on the catalyst surface through ionic liquids and methanol solvents.

Efficient Selective Carbon Dioxide Separation via Task-Specific Ionic Liquids Incorporated in ZIF-8.

Owing to the rapid increase in anthropogenic emission of carbon dioxide (CO2) in the atmosphere, which has resulted in a number of global climate challenges, a decrease in CO2 emissions is urgently needed in the current scenario. This study focuses on the development and characterization of composites for carbon dioxide (CO2) separation. The composites consist of two task-specific ionic liquids (TSILs), namely, tetramethylgunidinium imidazole [TMGHIM] and tetramethylgunidinium phenol [TMGHPhO], impregnated in ZIF-8. The performance of CO2 separation, including sorption capacity and selectivity, was evaluated for pristine ZIF-8 and composites of TMGHIM@ZIF-8 and TMGHPhO@ZIF-8. To demonstrate the thermal stability of the material, thermogravimetric analysis (TGA) was performed. Additionally, powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) were utilized to showcase the crystal structures and morphology. Fourier transform infrared spectroscopy (FTIR) and BET were also utilized to confirm the successful incorporation of TSILs into ZIF-8. The composite synthesized with TMGHIM@ZIF-8 demonstrated superior CO2 sorption performance as compared with TMGHPhO@ZIF-8. This is attributed to its strong attraction toward CO2, resulting in a higher CO2/CH4 selectivity of 110 while pristine MOFs showed 12 that is 9 times higher than that of the pristine ZIF-8. These TSILs@ZIF-8 composites have significant potential in designing sorbent materials for efficient acid gas separation applications.

Mechanical manipulation for ordered topological defects.

Randomly distributed topological defects created during the spontaneous symmetry breaking are the fingerprints to trace the evolution of symmetry, range of interaction, and order parameters in condensed matter systems. However, the effective mean to manipulate topological defects into ordered form is elusive due to the topological protection. Here, we establish a strategy to effectively align the topological domain networks in hexagonal manganites through a mechanical approach. It is found that the nanoindentation strain gives rise to a threefold Magnus-type force distribution, leading to a sixfold symmetric domain pattern by driving the vortex and antivortex in opposite directions. On the basis of this rationale, sizeable mono-chirality topological stripe is readily achieved by expanding the nanoindentation to scratch, directly transferring the randomly distributed topological defects into an ordered form. This discovery provides a mechanical strategy to manipulate topological protected domains not only on ferroelectrics but also on ferromagnets/antiferromagnets and ferroelastics.

Polyimide/Ionic Liquids Hybrid Membranes with NH3-Philic Channels for Ammonia-Based CO2 Separation Processes.

An efficient separation technology involving ammonia (NH3) and carbon dioxide (CO2) is of great importance for achieving low-carbon economy, environmental protection, and resource utilization. However, directly separating NH3 and CO2 for ammonia-based CO2 capture processes is still a great challenge. Herein, we propose a new strategy for selective separation of NH3 and CO2 by functional hybrid membranes that integrate polyimide (PI) and ionic liquids (ILs). The incorporated protic IL [Bim][NTf2] is confined in the interchain segment of PI, which decreases the fractional free volume and narrows the gas transport channel, benefiting the high separation selectivity of hybrid membranes. At the same time, the confined IL also provides high NH3 affinity for transport channels, promoting NH3 selective and fast transport owing to strong hydrogen bonding interaction between [Bim][NTf2] and NH3 molecules. Thus, the optimal hybrid membrane exhibits an ultrahigh NH3/CO2 ideal selectivity of up to 159 at 30 °C without sacrificing permeability, which is 60 times higher than that of the neat PI membrane and superior to the state-of-the art reported values. Moreover, the introduction of [Bim][NTf2] also reduces the permeation active energy of NH3 and reverses the hybrid membrane toward "NH3 affinity", as understood by studying the effect of temperature. Also, NH3 molecules are much easier to transport at high temperature, showing great application potential in direct NH3/CO2 separation. Overall, this work provides a promising ultraselective membrane material for ammonia-based CO2 capture processes.

A cusp catastrophe model for analyzing sudden channel shifting in wandering reach of the Lower Yellow River.

Sudden channel shifting of wandering rivers poses significant challenges for river engineering, flood control strategies, and the security of water resources. This study proposes a novel analytical model to quantitatively assess such channel shifts based on the cusp catastrophe theory. Utilizing bathymetric data from 93 river sections collected biannually between 2015 and 2019, a comprehensive investigation of channel instability in the wandering reach of the Lower Yellow River was conducted. The results show that both lateral and longitudinal stabilities in the Huayuankou-Gaocun section were generally favorable. For the most part of the selected sections demonstrated a propensity for gradual change. Out of the 93 sections, totally 45 were identified as being susceptible to sudden channel shifts. These vulnerable sections were predominantly located in two highly active reaches-Xiaodabin-Jinglonggong and Huayuankou-Zhaolanzhuang-during the period from 2015 to 2017, excluding the 2018-2019 non-flood season. In the latter non-flood period, nearly half of the sections in the downstream reach from Jinglonggong displayed instability. Our findings are consistent closely with empirical observations from the Lower Yellow River. Additionally, the changed flow and sediment conditions in the 2015-2019 and the efficiency of guide works have significant effects on the stability of river channels.

Revolutionary technology of low-carbon chemical processes.

This perspective depicts a green hydrogen and green electricity-driven low-carbon future for chemical industry, which requires revolutionary technologies from feedstock replacements, catalyst and reactor innovations to integrated intelligent systems.

Effective Absorption of Dichloromethane Using Carboxyl-Functionalized Ionic Liquids.

Dichloromethane (DCM) is recognized as a very harmful air pollutant because of its strong volatility and difficulty to degrade. Ionic liquids (ILs) are considered as potential solvents for absorbing DCM, while it is still a challenge to develop ILs with high absorption performances. In this study, four carboxyl-functionalized ILs-trioctylmethylammonium acetate [N1888][Ac], trioctylmethylammonium formate [N1888][FA], trioctylmethylammonium glycinate [N1888][Gly], and trihexyl(tetradecyl)phosphonium glycinate [P66614][Gly]-were synthesized for DCM capture. The absorption capacity follows the order of [P66614][Gly] > [N1888][Gly] > [N1888][FA] > [N1888][Ac], and [P66614][Gly] showed the best absorption capacity, 130 mg DCM/g IL at 313.15 K and a DCM concentration of 6.1%, which was two times higher than the reported ILs [Beim][EtSO4] and [Emim][Ac]. Moreover, the vapor-liquid equilibrium (VLE) of the DCM + IL binary system was experimentally measured. The NRTL (non-random two-liquid) model was developed to predict the VLE data, and a relative root mean square deviation (rRMSD) of 0.8467 was obtained. The absorption mechanism was explored via FT-IR spectra, 1H-NMR, and quantum chemistry calculations. It showed a nonpolar affinity between the cation and the DCM, while the interaction between the anion and the DCM was a hydrogen bond. Based on the results of the study of the interaction energy, it was found that the hydrogen bond between the anion and the DCM had the greatest influence on the absorption process.

Copper Recovery from Industrial Bimetallic Composite Ionic Liquids by Direct Electrodeposition and the Effect of Temperature and Ultrasound.

Critical processing protocols of industrial bimetallic composite ionic liquid (IL) are necessary to assure good mass transfer rates for process optimization and efficient metal recovery. Here, the effects of different conditions on the electrochemical behavior and copper recovery from the industrial bimetallic composite IL are crucial for effective resource utilization. Cyclic voltammetry (CV) shows that the reduction of Cu(I) to Cu(0) during the cathodic reduction region is the irreversible diffusion-controlled process, and the diffusion coefficient increased with temperature which indicated that increasing temperature could promote the diffusion and mass transfer. During electrodeposition, metallic copper is obtained exclusively on the cathode, while CuCl2 accumulates exclusively on the anode. Scanning electron microscopy shows that the micron-size electrodeposits become larger and significantly rougher with increasing temperature and ultrasonic frequency, illustrating that these factors hasten the nucleation and crystallization rates at high overpotentials. The efficiency of copper recovery is greatly improved by employing high temperature and ultrasonic cavitation, and the highest values correspond to r = 76.9% at 80 °C and r = 63.6% at 40 kHz. The study lays the foundation for efficient and rapid recovery of copper from spent ILs.

Studies on the Prediction and Extraction of Methanol and Dimethyl Carbonate by Hydroxyl Ammonium Ionic Liquids.

The separation of dimethyl carbonate (DMC) and methanol is of great significance in industry. In this study, ionic liquids (ILs) were employed as extractants for the efficient separation of methanol from DMC. Using the COSMO-RS model, the extraction performance of ILs consisting of 22 anions and 15 cations was calculated, and the results showed that the extraction performance of ILs with hydroxylamine as the cation was much better. The extraction mechanism of these functionalized ILs was analyzed by molecular interaction and the σ-profile method. The results showed that the hydrogen bonding energy dominated the interaction force between the IL and methanol, and the molecular interaction between the IL and DMC was mainly Van der Waals force. The molecular interaction changes with the type of anion and cation, which in turn affects the extraction performance of ILs. Five hydroxyl ammonium ILs were screened and synthesized for extraction experiments to verify the reliability of the COSMO-RS model. The results showed that the order of selectivity of ILs predicted by the COSMO-RS model was consistent with the experimental results, and ethanolamine acetate ([MEA][Ac]) had the best extraction performance. After four regeneration and reuse cycles, the extraction performance of [MEA][Ac] was not notably reduced, and it is expected to have industrial applications in the separation of methanol and DMC.

Amelioration of metabolic disorders in H9C2 cardiomyocytes induced by PM2.5 treated with vitamin C.

OBJECTIVE: Particulate matter with an aerodynamic diameter ≤2.5 µm (PM2.5) is a public health risk. We investigate PM2.5 on metabolites in cardiomyocytes and the influence of vitamin C on PM2.5 toxicity. MATERIALS AND METHODS: For 24 hours, H9C2 were exposed to various concentrations of PM2.5 (0, 100, 200, 400, 800 µg/ml), after which the levels of reactive oxygen species (ROS) and cell viability were measured using the cell counting kit-8 (CCK-8) and 2',7'-dichlorofluoresceindiacetate (DCFH2-DA), respectively. H9C2 were treated with PM2.5 (200 µg/ml) in the presence or absence of vitamin C (40 µmol/L). mRNA levels of interleukin 6(IL-6), caspase-3, fatty acid-binding protein 3 (FABP3), and hemeoxygenase-1 (HO-1) were investigated by quantitative reverse-transcription polymerase chain reaction. Non-targeted metabolomics by LC-MS/MS was applied to evaluate the metabolic profile in the cell. RESULTS: Results revealed a concentration-dependent reduction in cell viability, death, ROS, and increased expression of caspase-3, FABP3, and IL-6. In total, 15 metabolites exhibited significant differential expression (FC > 2, p < 0.05) between the control and PM2.5 group. In the PM2.5 group, lysophosphatidylcholines (LysoPC,3/3) were upregulated, whereas amino acids (5/5), amino acid analogues (3/3), and other acids and derivatives (4/4) were downregulated. PM2.5 toxicity was lessened by vitamin C. It reduced PM2.5-induced elevation of LysoPC (16:0), LysoPC (16:1), and LysoPC (18:1). DISCUSSION AND CONCLUSIONS: PM2.5 induces metabolic disorders in H9C2 cardiomyocytes that can be ameliorated by treatment with vitamin C.

Modelling toluene sorption in ionic liquid/metal organic framework composite materials.

Toluene is a prevalent pollutant in indoor environments and its removal is essential to maintain a healthy environment. Adsorption is one of the best alternatives for organic vapours removal, specially at low indoor concentrations. Metal Organic Frameworks (MOFs) and Ionic Liquids (ILs) are potential materials for this mean. In this work, the synthesis and application of IL/MOF composite materials for toluene removal is reported. Loading [BMIM][CH3COO] ionic liquid into MIL101 porous structure improves parent materials affinity towards toluene capture by two orders of magnitude (as Henry's constants, attesting to their synergy). MIL101(Cr) and absorption in [BMIM][CH3COO] IL is best described by Henry's Law, while the Langmuir adsorption model predicts toluene adsorption on [BMIM][CH3COO]/MIL101(Cr) better than Freundlich and Toth equations. Diffusional and kinetics models revealed that toluene diffusion is the rate limiting step for pristine MIL101. Kinetic and diffusion rates were systematically improved upon the incorporation of the ionic liquid due to shorter toluene hops with the adsorbed IL and the increased hydrophobicity in the composites making the sorption more favourable. This study provides a systematic analysis and modelling of the toluene capture process in IL/MOF composites aiding a better understanding of the sorption process in these novel materials.

Multi-excitation wavelength of gold nanocluster-based fluorescence sensor array for sulfonamides discrimination.

Sulfonamides (SAs) are widely used in many fields because of their advantages, including low price, wide antibacterial spectrum, and high stability. However, their accumulation in the human body leads to a variety of serious diseases. Therefore, it is necessary to design a convenient, effective, and sensitive method to detect SAs. Moreover, the fluorescence excitation spectrum has rich information characteristics, especially for the interaction between fluorophore and quencher via various mechanisms. However, the excitation wavelength-guided sensor array construction does not draw proper attention. To address these issues, we used BSA-AuNCs as a single probe to construct a sensor array for the detection of five SAs. The selected SAs showed different quenching effects on the fluorescence intensities of BSA-AuNCs. The changes in the fluorescence intensity at different excitation wavelengths (λ = 230, 250, and 280 nm) have been applied to construct our sensor array and address the distinguishability between the selected SAs. With helping of pattern recognition methods, five different SAs have been identified at three different concentrations. Additionally, qualitative analysis at different moral ratios and quantitative analysis at nanogram concentrations have been considered. Moreover, the proposed sensor array was successfully used to distinguish between different SAs in commercial milk with an accuracy of 100 %. This study provides a simple and powerful approach to SAs detection. Also, it shows a broad application prospect in the field of food and drug monitoring.

Effect of Halide Anions on the Electroreduction of CO2 to C2 H4 : A Density Functional Theory Study.

The halide anions present in the electrolyte improve the Faradaic efficiencies (FEs) of the multi-hydrocarbon (C2+ ) products for the electrochemical reduction of CO2 over copper (Cu) catalysts. However, the mechanism behind the increased yield of C2+ products with the addition of halide anions remains indistinct. In this study, we analysed the mechanism by investigating the electronic structures and computing the relative free energies of intermediates formed from CO2 to C2 H4 on the Cu (100) facet based on density functional theory (DFT) calculations. The results show that formyl *CHO from the hydrogenation reaction of the adsorbed *CO acts as the key intermediate, and the C-C coupling reaction occurs preferentially between *CHO and *CO with the formation of a *CHO-CO intermediate. We then propose a free-energy pathway of C2 H4 formation. We find that the presence of halide anions significantly decreases the free energy of the *CHOCH intermediate, and enhances desorption of C2 H4 in the order of I- >Cl- >Br- >F- . Lastly, the obtained results are rationalized through Bader charge analysis.

Unravelling the electromechanical coupling in a graphene/bulk h-BN heterostructure.

The stacking heterostructure of graphene on bulk h-BN produces a moiré pattern with topographic corrugation. The corrugation of the moiré pattern expectantly induces a considerable curvature and a flexoelectric response, which calls for a detailed study. In this work, we used lateral force microscopy, a scanning technique to locally observe the moiré pattern and topographic corrugation. The curvature and flexoelectric potentials are derived from the measured topographic corrugation, revealing a huge curvature of ∼107 m-1 and a flexoelectric potential of ∼10 mV in the hexagonal domain wall region (∼3-4 nm) of the moiré pattern. In addition, the domain walls of the moiré pattern also generate a clear electromechanical and frictional response, arising from the corrugation-induced flexoelectric response. In summary, the results of this work provide insights into the understanding of the flexoelectricity in the graphene/bulk h-BN and its associated electromechanical coupling behavior in the moiré pattern of a van der Waals stacking heterostructure.

Natural Deep Eutectic Solvents Enhanced Electro-Enzymatic Conversion of CO2 to Methanol.

Electro-enzymatic conversion of CO2 offers a promising solution for CO2 utilization, while the conversion rate and efficiency were disappointing. To address the challenge, four kinds of natural deep eutectic solvents (NADES) with desirable biocompatibility were developed for the first time and used as the co-electrolyte in the electro-enzymatic conversion of CO2. As a result, the SerGly-based solution presents high CO2 solubility and high electrocatalytic activity, compared to the conventional buffer. By applying SerGly in the electro-enzymatic conversion of CO2, the yield of the product (methanol) is two times higher than that in the Tris-HCl buffer (0.22 mM) and 16 times higher than the control reaction.

Characteristics of SARS-CoV-2 transmission in a medium-sized city with traditional communities during the early COVID-19 epidemic in China.

The nationwide COVID-19 epidemic ended in 2020, a few months after its outbreak in Wuhan, China at the end of 2019. Most COVID-19 cases occurred in Hubei Province, with a few local outbreaks in other provinces of China. A few studies have reported the early SARS-CoV-2 epidemics in several large cities or provinces of China. However, information regarding the early epidemics in small and medium-sized cities, where there are still traditionally large families and community culture is more strongly maintained and thus, transmission profiles may differ, is limited. In this study, we characterized 60 newly sequenced SARS-CoV-2 genomes from Anyang as a representative of small and medium-sized Chinese cities, compared them with more than 400 reference genomes from the early outbreak, and studied the SARS-CoV-2 transmission profiles. Genomic epidemiology revealed multiple SARS-CoV-2 introductions in Anyang and a large-scale expansion of the epidemic because of the large family size. Moreover, our study revealed two transmission patterns in a single outbreak, which were attributed to different social activities. We observed the complete dynamic process of single-nucleotide polymorphism development during community transmission and found that intrahost variant analysis was an effective approach to studying cluster infections. In summary, our study provided new SARS-CoV-2 transmission profiles representative of small and medium-sized Chinese cities as well as information on the evolution of SARS-CoV-2 strains during the early COVID-19 epidemic in China.

Manipulation of current rectification in van der Waals ferroionic CuInP2S6.

Developing a single-phase self-rectifying memristor with the continuously tunable feature is structurally desirable and functionally adaptive to dynamic environmental stimuli variations, which is the pursuit of further smart memristors and neuromorphic computing. Herein, we report a van der Waals ferroelectric CuInP2S6 as a single memristor with superior continuous modulation of current and self-rectifying to different bias stimuli (sweeping speed, direction, amplitude, etc.) and external mechanical load. The synergetic contribution of controllable Cu+ ions migration and interfacial Schottky barrier is proposed to dynamically control the current flow and device performance. These outstanding sensitive features make this material possible for being superior candidate for future smart memristors with bidirectional operation mode and strong recognition to input faults and variations.

Prediction of the Liquid-Liquid Extraction Properties of Imidazolium-Based Ionic Liquids for the Extraction of Aromatics from Aliphatics.

Liquid-liquid extraction (LLE) is an important technique to separate aromatics from aliphatics since these compounds have very similar boiling points and cannot be separated by distillation. Ionic liquids (ILs) are considered as potential extractants to extract aromatics from aliphatics. In this paper, molecular dynamics (MD) simulations were used to predict the extraction property (i.e., capacity and selectivity) of ILs for the LLE of aromatics from aliphatics. The extraction properties of seven different ILs including [C2mim][Tf2N], [C2mim][TFO], [C2mim][SCN], [C2mim][DCA], [C2mim][TCM], [C4mim][Tf2N], and [C8mim][Tf2N] were investigated. Results show that ILs with shorter alkyl chain cations and [Tf2N]- anion exhibit better extraction efficiency than other ILs, which is in agreement with previously reported experimental data on the extraction of toluene from aliphatics and further validated the reliability of the proposed model. The binding energies between ILs and organic molecules were calculated by the density functional theory, which help explain the different extraction behaviors of different ILs. The symmetry-adapted perturbation theory analysis was performed to further understand the interaction mechanisms between ILs and organics. Our study shows that the [Tf2N]- anion also has the best extraction capability for heavier aromatics (o-xylene, m-xylene, and p-xylene) from common aliphatics (heptane and octane). The MD modeling approach can be a low-cost in silico tool for the high-throughput fast screening of ILs for the LLE of aromatics from aliphatics.