Robust and Durable Superhydrophobic Polyurethane Sponge for Oil/Water Separation

With the purpose of purging and recycling oil and organic solvent from a water surface, a superhydrophobic polyurethane (PU) sponge was fabricated through a combined method of interfacial polymerization (IP) and molecular self-assembly. The as-prepared sponge has a superwetting characteristic of superlipophilicity in atmosphere and superhydrophobicity both in atmosphere and under oil, and it can quickly and selectively absorb various kinds of oils up to 29.9 times its own weight. More importantly, because of a covalent combination of the sponge skeleton and the polyamide thin film from IP, the superhydrophobic sponges could be reused for oil/water separation over 500 cycles without losing its superhydrophobicity, showing the highest reusability among the reported absorptive materials. The superhydrophobic sponge also can be used in the continuous absorption and expulsion of oils and organic solvents from water surfaces with the help of a vacuum pump. All of these features make the sponge a promising candidate material for oil-spill cleanups

Robust and Durable Superhydrophobic Polyurethane Sponge for Oil/Water Separation

With the purpose of purging and recycling oil and organic solvent from a water surface, a superhydrophobic polyurethane (PU) sponge was fabricated through a combined method of interfacial polymerization (IP) and molecular self-assembly. The as-prepared sponge has a superwetting characteristic of superlipophilicity in atmosphere and superhydrophobicity both in atmosphere and under oil, and it can quickly and selectively absorb various kinds of oils up to 29.9 times its own weight. More importantly, because of a covalent combination of the sponge skeleton and the polyamide thin film from IP, the superhydrophobic sponges could be reused for oil/water separation over 500 cycles without losing its superhydrophobicity, showing the highest reusability among the reported absorptive materials. The superhydrophobic sponge also can be used in the continuous absorption and expulsion of oils and organic solvents from water surfaces with the help of a vacuum pump. All of these features make the sponge a promising candidate material for oil-spill cleanups

Robust and Durable Superhydrophobic Polyurethane Sponge for Oil/Water Separation

With the purpose of purging and recycling oil and organic solvent from a water surface, a superhydrophobic polyurethane (PU) sponge was fabricated through a combined method of interfacial polymerization (IP) and molecular self-assembly. The as-prepared sponge has a superwetting characteristic of superlipophilicity in atmosphere and superhydrophobicity both in atmosphere and under oil, and it can quickly and selectively absorb various kinds of oils up to 29.9 times its own weight. More importantly, because of a covalent combination of the sponge skeleton and the polyamide thin film from IP, the superhydrophobic sponges could be reused for oil/water separation over 500 cycles without losing its superhydrophobicity, showing the highest reusability among the reported absorptive materials. The superhydrophobic sponge also can be used in the continuous absorption and expulsion of oils and organic solvents from water surfaces with the help of a vacuum pump. All of these features make the sponge a promising candidate material for oil-spill cleanups

Mechanistic Study of the Asymmetric Carbonyl-Ene Reaction between Alkyl Enol Ethers and Isatin Catalyzed by the <i>N</i>,<i>N</i>′‑Dioxide–Mg(OTf)₂ Complex

The mechanism and origin of the stereoselectivity of the asymmetric carbonyl-ene reaction between <i>N</i>-methyl-protected isatin and 2-methyloxypropene catalyzed by the <i>N</i>,<i>N</i>′-dioxide–Mg­(OTf)₂ complex were investigated by DFT and ONIOM methods. The background reaction occurred via a two-stage, one-step mechanism with a high activation barrier of 30.4 kcal mol^–1 at the B3LYP-D3­(BJ)/6-311G**­(SMD, CH₂Cl₂)//B3LYP/6-31G*­(SMD, CH₂Cl₂) level at 303 K. Good linear correlations between the global nucleophilicity index (<i>N</i>) and the activation energy barrier (Δ<i>G</i>^⧧) were found. The chiral <i>N</i>,<i>N</i>′-Mg­(II) complex catalyst could enhance the electrophilicity of the isatin substrate by forming hexacoordinate Mg­(II) reactive species. The substituent at the <i>ortho</i> positions of aniline combined with the aliphatic ring of the backbone in the chiral <i>N</i>,<i>N</i>′-dioxide ligand played an important role in the construction of a favorable “pocket-like” chiral environment (chiral pocket) around the Mg­(II) center, directing the preferential orientation of the incoming substrate. An unfavorable steric arrangement in the <i>re</i>-face attack pathway translated into a more destabilizing activation strain of the ene substrate, enhancing enantiodifferentiation of two competing pathways for the desired <i>R</i> product. This work also suggested a new phosphine ligand (<b>N-L1</b>) for the formation of the Mg­(II) complex catalyst for the asymmetric carbonyl-ene reaction. The chiral environment and Lewis acidity of the Mg­(II) complex could be fine-tuned by introduction of P-donor units into the ligand for highly efficient asymmetric catalysis

Use of In Vitro Systems To Model In Vivo Degradation of Therapeutic Monoclonal Antibodies

Major degradation pathways such as deamidation, isomerization, oxidation, and glycation may be accelerated after administration of antibody therapeutics to the patient. Tracking in vivo product degradation is important because certain post-translational modifications can inactivate the protein and reduce product efficacy. However, in vivo characterization of protein therapeutics is not routinely performed because of technical challenges and limited sample availability. In vitro models offer several potential advantages, including larger sample supplies, simpler and faster methods for sample preparation and analysis, and the potential to distinguish differences in product degradation from differences in product clearance. In this study, we compared the rates of in vivo product degradation using mAb1 recovered from clinical serum samples with the rates of in vitro product degradation using mAb1 recovered from spiked phosphate buffered saline (PBS) and spiked human serum samples to determine if results from the in vitro model systems could be used to predict the in vivo results. The antibody samples were characterized by peptide mapping or intact mass analysis to quantify multiple quality attributes simultaneously, including deamidation, isomerization, oxidation, N-terminal pyroglutamate formation, and glycation. It was clearly demonstrated that both the spiked PBS and spiked serum models were effective in predicting in vivo results for deamidation, isomerization, N-terminal pyroglutamate formation and glycation, whereas only the spiked serum model was effective in predicting in vivo results for oxidation

Influence of Phosphorus Configuration on Electronic Structure and Oxygen Reduction Reactions of Phosphorus-Doped Graphene

Encouraged by the great promise of heteroatoms-doped carbon materials for catalyzing the oxygen reduction reaction (ORR) in fuel cells, phosphorus-doped carbon has exhibited high catalytic activity for the ORR. Here, by means of comprehensive density functional theory (DFT) computations, we explored the relationships among the catalytic activity, stability, and the local chemical bonding states at dopant sites of P-doped graphene sheets for ORR to identify the most optimized P-doped graphene structure. The structures show that the P atom can substitute one or two C atoms to form P-doped graphene structures with three or four P–C bonds (PC3G or PC4G), respectively, and these structures are easily oxidized into the OPC3G and OPC4G models with P–O bond. The further calculations reveal that the stability, band structure, surface charge distribution, potential active sites, and free energy of the rate-determining step of P-doped graphene can be modulated effectively by the chemical bonding states of P atom and the formation of C–P–O bond. The OPC3G model is the most effective and stable P-doped graphene for ORR due to its stability, activity, and the amount of the potential active sites. Another significant finding is that the C atoms possessed high negative charge, which also can be the optimal active sites for ORR. Our work provides useful guidance for the rational design and fabrication of P-doped graphene framework and helpful further activity enhancement

Synthesis, Crystal Structures, and Biological Activity Evaluation of Novel Xanthine Derivatives Containing a Pyrethroid Moiety

On the basis of the structures of natural xanthines and pyrethroid insecticides, a series of novel xanthine derivatives Ia–Is containing pyrethroid motifs were synthesized and identified by means of melting points, 1H NMR, 13C NMR, and HRMS. The single crystals of compounds In and Iq were obtained, which further confirmed the structures and configurations of this type of compounds. The biological tests showed that some of them exhibited favorable insecticidal activities toward Mythimna separata Walker and Plutella xylostella L. and were superior to the natural methylxanthine compound caffeine and comparable with the insecticide tetramethrin (e.g., compound Im: LC50 = 0.6162 mg/L, against P. xylostella). Among others, Im, Ib, Ij, and Ik could serve as new insecticidal leading structures for further study. Moreover, some of the compounds showed favorable fungicidal activities against a broad spectrum of plant pathogenic fungi (e.g., compound Ie: EC50 = 6.0922 μg/mL, against Physalospora piricola; EC50 = 9.0637 μg/mL, against Rhizoctonia cerealis), which in turn would be an exciting new finding in xanthine chemistry; Ie, Ih, and Ii could be novel fungicidal leading compounds for further investigation. The structure–activity relationships of the compounds were also analyzed and discussed in detail. The research results presented in this paper provide a useful reference and guidance for the development of new natural product-based agrochemicals

Efficient Demulsification of Diesel-in-Water Emulsions by Different Structural Dendrimer-Based Demulsifiers

A series of amine-based dendrimer polyamidoamine (PAMAM) demulsifiers with different initial cores were synthesized and investigated in the demulsification process of diesel-in-water emulsions. With the aim of systemic evaluation of their demulsification performance, some important factors of the demulsification processes were investigated including demulsifier dosage, settling time, temperature, oil content, and kinds of diesel. The demulsifier with the triethylenetetramine (TETA) initial core provided excellent demulsification performance by removing oil with less dosage and at relatively low temperature in short periods and reached 96.66% demulsification efficiency for catalytic cracking diesel emulsion. The results showed its good application prospects. In order to gain insight into the demulsification process and mechanism, some measurement methods were adopted. Micrograph and droplet size distribution of emulsions illustrated that the PAMAM demulsifier could lead to the breakup of diesel-in-water emulsions by flocculation and coalescence. The surface tension and interfacial tension gave a basic understanding of the demulsification mechanism. Zeta potential indicated that emulsion had been broken up. The conductivity measurement explained the demulsification mechanism from the aspect of the electrostatic interactions of moving droplets. The dendrimer and SDS had strong aggregation interactions in the system according to the results of hydrodynamic radium

DataSheet1_Quantitative provenance analysis through deep learning of rare earth element geochemistry: A case from the Liuling Group of the East Qinling Orogen, Central China.XLSX

With the ever-growing availability of massive geo-data, deep learning has been widely applied to geoscientific questions such as sedimentary provenance analysis. However, randomly selected initial weights (and also biases) and possible loss of population diversity in traditional neural network learning remain problematic. To address this issue, in this study, we proposed a new deep neural network model by incorporating genetic algorithm (GA) and simulated annealing algorithm into the BP neural network, i.e., the GA-SA-BP model. We then applied this new model to rare earth element (REE) geochemical data of the Liuling Group of the East Qinling Orogen to investigate its provenance. Our results showed that among other deep learning algorithms, the new model presents the best performance with good measuring metrics (e.g., over 85% of accuracy, over 0.82 of F1-macro-average, F1-micro-average, and Kappa coefficient, and smallest (<0.15) Hamming distance). Here, we interpreted in accordance with the classification results that the southern margin of the North China Craton and the South Qinling Orogen are likely two major sources of the Liuling Group, suggesting a bidirectional deposition route of sediments from the north and south. Therefore, we proposed a foreland basin environment as the likely tectonic setting for the Liuling Group, which is consistent with current geological understanding. Our observations suggested that the GA-SA-BP model (or improved deep learning models) coupled with REE geochemistry is capable of provenance analysis.</p

Development of Crystalline Covalent Triazine Frameworks to Enable <i>In Situ</i> Preparation of Single-Atom Ni–N₃–C for Efficient Electrochemical CO₂ Reduction

The synthesis of highly crystalline covalent triazine frameworks (CTFs) with fully conjugated nitrogen-enriched architectures is a long-term challenging subject. Herein, a solvent- and catalyst-free approach was implemented for the first time to create crystalline CTFs based on a new trimerization of amidine-type monomers. A highly crystalline triazine-linked polymer with a specific surface area of 255 m2 g–1 was achieved, whereas additional aldehydes were no longer required. Furthermore, an in situ transformation strategy was developed by exploring a molten salt (ZnCl2) to promote this new condensation, so as to convert as-obtained CTFs into isolated single-atom catalysts (SACs). Interestingly, the usage of ZnCl2 not only enables a crystalline CTF with a significantly enhanced surface area, up to 663 m2 g–1 but also provides a means of realizing atomically dispersed nickel (Ni) catalysts with unique Ni–N3–C sites. As a result, the resulting SAC exhibits efficient electrochemical carbon dioxide (CO2) reduction performance, where a maximum Faradaic efficiency for carbon monoxide (CO) production of 97.5% at −0.52 V (vs. reversible hydrogen electrode, RHE) and an excellent turnover frequency (3192 h–1) with a current density of 23.32 mA cm–2 at −1.02 V can be obtained, respectively. We anticipate our findings will facilitate new possibilities for the development of crystalline porous organic frameworks and SACs for various catalysis