Effective C4 Separation by Zeolite Metal-Organic Framework Composite Membranes.

Inorganic zeolites have excellent molecular sieving properties, but they are difficult to process into macroscopic structures. In this work, we use metal-organic framework (MOF) glass as substrates to engineer the interface with inorganic zeolites, and then assemble the discrete crystalline zeolite powders into monolithic structures. The zeolites are well dispersed and stabilized within the MOF glass matrix, and the monolith has satisfactory mechanical stabilities for membrane applications. We demonstrate the effective separation performance of the membrane for 1,3-butadiene (C4H6) from other C4 hydrocarbons, which is a crucial and challenging separation in the chemical industry. The membrane achieves a high permeance of C4H6 (693.00±21.83 GPU) and a high selectivity over n-butene, n-butane, isobutene, and isobutane (9.72, 9.94, 10.31, and 11.94, respectively). This strategy opens up new possibilities for developing advanced membrane materials for difficult hydrocarbon separations.

Total Face Reconstruction with Flap Prefabrication and Soft-Tissue Expansion Techniques.

SUMMARY: Total facial deformities always lead to psychological and functional consequences, making plastic and reconstructive surgery a great challenge. The skin of the anterior chest area is matched in thickness, texture, and color to the head and face. The purpose of this article was to discuss and evaluate reconstructive surgeons' experiences with obtaining a monoblock flap from the anterior thoracic area for entire face reconstruction using flap prefabrication, soft-tissue expansion, and facial plastic surgery following skin flap transplantation. Two patients underwent prefabricated expanded anterior thoracic flap reconstructions for total facial deformities; data collection included face defect size, flap type, the shape of the expander, expansion time, and complications. All the face flaps that were transplanted survived without major complications. It is concluded that using a prefabricated expanded flap to reconstruct an entire facial soft-tissue defect can provide a high degree of matching, a wide enough covering area, and a thin enough skin thickness to cover the face. Autologous flap grafting is easy to implement and has a high application value.

Large-Area Ultrathin Metal-Organic Framework Membranes Fabricated on Flexible Polymer Supports for Gas Separations.

Ultrathin continuous metal-organic framework (MOF) membranes have the potential to achieve high gas permeance and selectivity simultaneously for otherwise difficult gas separations, but with few exceptions for zeolitic-imidazolate frameworks (ZIF) membranes, current methods cannot conveniently realize practical large-area fabrication. Here, we propose a ligand back diffusion-assisted bipolymer-directed metal ion distribution strategy for preparing large-area ultrathin MOF membranes on flexible polymeric support layers. The bipolymer directs metal ions to form a cross-linked two-dimensional (2D) network with a uniform distribution of metal ions on support layers. Ligand back diffusion controls the feed of ligand molecules available for nuclei formation, resulting in the continuous growth of large-area ultrathin MOF membranes. We report the practical fabrication of three representative defect-free MOF membranes with areas larger than 2,400 cm2 and ultrathin selective layers (50-130 nm), including ZIFs and carboxylate-linker MOFs. Among these, the ZIF-8 membrane displays high gas permeance of 3,979 GPU for C3H6, with good mixed gas selectivity (43.88 for C3H6/C3H8). To illustrate its scale-up practicality, MOF membranes were prepared and incorporated into spiral-wound membrane modules with an active area of 4,800 cm2. The ZIF-8 membrane module presents high gas permeance (3,930 GPU for C3H6) with acceptable ideal gas selectivity (37.45 for C3H6/C3H8).

Microenvironment Remodeling Self-Healing Hydrogel for Promoting Flap Survival.

Random flap grafting is a routine procedure used in plastic and reconstructive surgery to repair and reconstruct large tissue defects. Flap necrosis is primarily caused by ischemia-reperfusion injury and inadequate blood supply to the distal flap. Ischemia-reperfusion injury leads to the production of excessive reactive oxygen species, creating a pathological microenvironment that impairs cellular function and angiogenesis. In this study, we developed a microenvironment remodeling self-healing hydrogel [laminarin-chitosan-based hydrogel-loaded extracellular vesicles and ceria nanozymes (LCH@EVs&CNZs)] to improve the flap microenvironment and synergistically promote flap regeneration and survival. The natural self-healing hydrogel (LCH) was created by the oxidation laminarin and carboxymethylated chitosan via a Schiff base reaction. We loaded this hydrogel with CNZs and EVs. CNZs are a class of nanomaterials with enzymatic activity known for their strong scavenging capacity for reactive oxygen species, thus alleviating oxidative stress. EVs are cell-secreted vesicular structures containing thousands of bioactive substances that can promote cell proliferation, migration, differentiation, and angiogenesis. The constructed LCH@EVs&CNZs demonstrated a robust capacity for scavenging excess reactive oxygen species, thereby conferring cellular protection in oxidative stress environments. Moreover, these constructs notably enhance cell migration and angiogenesis. Our results demonstrate that LCH@EVs&CNZs effectively remodel the pathological skin flap microenvironment and marked improve flap survival. This approach introduces a new therapeutic strategy combining microenvironmental remodeling with EV therapy, which holds promise for promoting flap survival.

Radiographic Study of the Nasal Valve in Different CT Evaluation Method in Asian Patients with Unilateral Cleft Lip Nose.

OBJECTIVE(S): It was the first study to apply and compare two CT methods to assess the validity and clinical significance of structural alterations of the nasal valve in patients with cleft lip nose for assessing nasal ventilation disturbance. METHODS: The study collected data from the NOSE score, as well as internal nasal valve area, internal nasal valve angle, external nasal valve area, and septal deviation angle, to evaluate the differences and correlations between those factors in patients with cleft lip and nose. RESULTS: There were significant differences among INV transverse and coronal area and INV angle on different axial standardized planes between clefted side and non-clefted side. There were statistically significant negative correlations between NOSE scores and those indicators of standard plane and acoustic-axis standardized coronal plane. NOSE score and NSD angle were the indicators of significant differences in the measured data of different complications groups (p = 0.002, p = 0.017). The correlation comparison showed that two standardized CT imaging transverse planes have similar correlations in NOSE score, NSD angle, and complications. CONCLUSION: The results of the two CT evaluation methods showed that there was a significant difference in nasal valve area on the cleft and non-cleft sides, which was significantly associated with nasal ventilation disturbance. The CT evaluation method based on standard axial 3D reconstruction is more convenient to use in the clinic, can be used for pre-surgical evaluation of nasal repair in patients with secondary nasal deformities of unilateral cleft lip, and is valuable for treatment. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A New Definition for Alar Flare Based on "Alar Flare Angle".

BACKGROUND: An accurate diagnosis and an appropriate treatment are important parts of successful rhinoplasty. We proposed a new definition for alar flares to guide our clinical work. METHODS: A retrospective study was conducted on patients with alar flares from July 2017 to July 2021, and the follow-up time ranged from 12 to 27 months, mean of 16 months. We defined the alar flare angle by the formation of two lines: the line that connects the alar to the alar root point and line that connects the alar to the pronasale. The alar flare angle, interalar distance and nasal base width were measured, and alar wedge excision or alar base excision and tip elevation were performed. Scars, complications and satisfaction scales were evaluated after surgery. Through an analysis of the database, we found that the ideal alar flare angle was between 130 degrees and 140 degrees. If it was less than 130 degrees, it represented alar flares, and patients asked for alar surgery. RESULTS: A total of 33 patients were included. All patients underwent tip elevation, 12 patients underwent external alar wedge excision, and 5 patients underwent external alar wedge excision and alar base excision. External alar wedge excision can be used to completely correct alar flares, and in our study, the alar flare angles were more than 130 degrees after surgery. One patient complained of an acceptable scar, and there was no infection or alar deformity. All patients were satisfied. CONCLUSIONS: We proposed a new definition in which an alar flare angle less than 130 degrees can be diagnosed as an alar flare. This new definition is valuable for the clinical diagnosis and treatment of alar flares. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Microplastics alter Cr accumulation and fruit quality in Cr(VI) contaminated soil-cucumber system during the lifecycle: Insight from rhizosphere bacteria and root metabolism.

Both microplastics and Cr(VI) potentially threaten soil and crops, but little is known about their interaction in the soil-plant system. This study investigated the effect and mechanism of polyethylene (PE), polyamide (PA), and polylactic acid (PLA) microplastics on Cr bioaccumulation and toxicity in a Cr(VI) contaminated soil-cucumber system during the lifecycle. The results show that microplastics had a greater effect on Cr accumulation in cucumber roots, stems, and leaves than in fruits. PE microplastics increased, but PA and PLA microplastics decreased the Cr accumulation in cucumber. Microplastics, especially high-dose, small, and aged microplastics, exacerbated the effects of accumulated Cr in cucumber on fresh weight and fruit yield. The nutrient contents in fruits except soluble sugars were reduced by microplastics. The random forest regression model shows that the microplastic type was the most important factor causing changes in the soil-cucumber system except for Cr(VI) addition. Under Cr(VI) and microplastic co-exposure, bacteria that could simultaneously tolerate Cr(VI) stress and degrade microplastics were enriched in the rhizosphere soil. The partial least squares path model shows that microplastics reduced the beneficial effect of the bacterial community on cucumber growth. Microplastics, especially PLA microplastics, alleviated the adverse effects of Cr(VI) stress on root metabolism.

A High-Performance N2-Selective MXene Membrane with Double Selectivity Mechanism for N2/CH4 Separation.

Membrane-based separation process for unconventional natural gas purification (mainly N2/CH4 separation) has attracted more attention due to its considerable economic benefits. However, the majority of separation membranes at this stage, particularly N2-selective membranes, achieve the desired separation target by mainly relying on the diffusivity-selectivity mechanism. To overcome the limitation of a single mechanism, 2D lamellar MXene membranes with a double selectivity mechanism are prepared to enhance N2 permeance and N2/CH4 selectivity via introducing unsaturated metal sites into MXene, which can form specific interactions with N2 molecules and enhance N2 permeation. The resulting membranes exhibit an inspiring N2/CH4 separation performance with an N2 permeance of 344 GPU and N2/CH4 selectivity of 13.76. The collaboration of the double selectivity mechanism provides a new idea for the development of a novel N2-selective membrane for N2 removal and CH4 purification, which further broadens the application prospects of membrane separation technology in the field of unconventional natural gas purification.

A New Classification of Pollybeak Deformity and Its Treatment in Asian Rhinoplasty.

BACKGROUND: Supratip deformity, also known as pollybeak deformity, is a common complication of primary and secondary rhinoplasty, characterized by fullness in the supratip region. The correction of pollybeak deformity is a challenging procedure, and its management requires a thorough understanding of the pathogenic mechanism of pollybeak deformity. OBJECTIVES: This study aimed to evaluate the effectiveness of surgical methods for correcting pollybeak deformity in Asian rhinoplasty. METHODS: A retrospective chart review was conducted for 53 patients who underwent pollybeak correction between 2021 and 2022. A modified classification system for pollybeak deformity, the Supratip Fullness Rating Scale (SFRS), was developed to evaluate supratip fullness. The aesthetic outcomes of the patients were assessed by surgeons using the visual analog scale (VAS), and patient was self-assessed using the Rhinoplasty Outcome Evaluation (ROE) scale. RESULTS: The study demonstrated that our surgical method resulted in satisfactory outcomes, with a mean SFRS score change from 2.34[0.65] to 0.23[0.42], a decrease in VAS score from 7.47[1.73] to 1.79[1.67] and a high satisfaction rate of 77.36%, calculated by ROE score. No complications were reported. CONCLUSION: Our surgical method for correcting pollybeak deformity in Asian rhinoplasty can result in satisfactory outcomes, particularly in terms of aesthetic appearance, without any side effects. The use of the modified classification system (SFRS) can provide an objective evaluation of supratip fullness, thereby aiding in the management of this challenging complication. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Toxicity of decabromodiphenyl ethane on lettuce: Evaluation through growth, oxidative defense, microstructure, and metabolism.

Decabromodiphenyl ethane (DBDPE) as the most widely used novel brominated flame retardants (NBFRs), has become a ubiquitous emerging pollutant in the environment. However, its toxic effects on vegetable growth during agricultural production have not been reported. In this study, we investigated the response mechanisms of hydroponic lettuce to DBDPE accumulation, antioxidant stress, cell structure damage, and metabolic pathways after exposure to DBDPE. The concentration of DBDPE in the root of lettuce was significantly higher than that in the aboveground part. DBDPE induced oxidative stress on lettuce, which stimulated the defense of the antioxidative system of lettuce cells, and the cell structure produced slight plasma-wall separation. In terms of metabolism, metabolic pathway disorders were caused, which are mainly manifested as inhibiting amino acid biosynthesis and metabolism-related pathways, interfering with the biosyntheses of amino acids, organic acids, fatty acids, carbohydrates, and other substances, and ultimately manifested as decreased total chlorophyll content and root activity. In turn, metabolic regulation alleviated antioxidant stress. The mechanisms of the antioxidative reaction of lettuce to DBDPE were elucidated by IBR, PLS-PM analysis, and molecular docking. Our results provide a theoretical basis and research necessity for the evaluation of emerging pollutants in agricultural production and the safety of vegetables.

A Retrospective Study on the Reconstruction of Nasal Septal Mucosal Defects after Asian Rhinoplasty.

BACKGROUND: Nasal septal mucosal defects following rhinoplasty in Asian patients are uncommon complications. However, the reconstruction of such defects presents a challenging task in plastic surgery. The aim of this study was to present comprehensive surgical strategies for the reconstruction of nasal septal mucosal defect after rhinoplasty. METHODS: Thirteen cases presenting with nasal septal mucosal defects between January 2016 and October 2021 were retrospectively reviewed. The size, location, and severity of the defect as well as the extent of cartilage exposure were taken into consideration during evaluation, and surgical approaches were employed for repair accordingly. Patient satisfaction was evaluated using a questionnaire with visual analog scale (VAS) and nasal obstruction symptom evaluation scale (NOSE). RESULTS: The average postoperative follow-up period in this study group was 10.15 months. Reconstruction of nasal septal mucosal defects resulted in successful treatment for all patients. There was no evidence of flap failure or nasal valve stenosis. All patients were satisfied with the reconstruction outcome. CONCLUSIONS: The successful application of surgical techniques for nasal septal mucosal defects after rhinoplasty requires comprehensive consideration. The utilization of the retrograde-flow superior labial artery mucosal flap appears to be a secure, efficient, and effective technique for nasal septal mucosal defect reconstruction in rhinoplasty, particularly in cases with cartilage exposure. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Insight into Bioaccumulation of Decabromodiphenyl Ethane in Eisenia fetida Increased by Microplastics.

The rise of electronics inevitably induced the co-pollution of novel brominated flame retardants (NBFRs) and microplastics (MPs). However, studies on how they interact to influence their bioavailability are scarce. Here, we explored the influence mechanism of acrylonitrile butadiene styrene (ABS)-MPs on the bioaccumulation of decabromodiphenyl ethane (DBDPE) in soil-earthworm microcosms. The influence exhibited a temporal pattern characterized by short-term inhibition and long-term promotion. After 28 days of exposure, DBDPE bioaccumulation in a co-exposure (10 mg kg-1 DBDPE accompanied by 1000 mg kg-1 ABS-MPs) was 2.61 times higher than that in a separate exposure. The adsorption process in the soil, intestines, and mucus introduced DBDPE-carried MPs, which had a higher concentration of DBDPE than the surrounding soil and directly affected the bioavailability of DBDPE. MP-pre-exposure (100, 1000, and 10000 mg kg-1) reduced epidermal soundness, mucus secretion, and worm cast production. This eventually promoted the contact between earthworm and soil particles and enhanced the DBDPE of earthworm tissue by 6%-61% in the next DBDPE-postexposure period, confirming that MPs increased DBDPE bioaccumulation indirectly by impairing the earthworm health. This study indicates that MPs promoted DBDPE bioaccumulation via adsorption and self-toxicity, providing new insight into the combined risk of MPs and NBFRs.

New classification system of contracted nose and its treatment algorithm.

BACKGROUND: The nasal contracture after rhinoplasty is one of the most severe complications in East Asian patients. The classification and treatment algorithm of nasal contracture have not yet been established. This study aimed to develop a new classification system and treatment algorithm of contracted noses in East Asian patients to improve treatment outcomes. METHODS: A retrospective study was conducted with 62 patients with nasal contracture who underwent a revision rhinoplasty between March 2017 and March 2021. The authors classified the 62 patients into 3 groups based on the classification system. All patients underwent rhinoplasty designed according to the corresponding classification. The patients were followed up after surgery, and the rhinoplasty outcomes evaluation (ROE) was used to evaluate their satisfaction rate. RESULTS: A total of 59 female patients and 3 male patients (mean age, 29.45 ± 7.73 years) were included in this study. Forty-five cases presented mild nasal contracture (72.58%), 11 presented moderate nasal contracture (17.74%), and 6 presented severe nasal contracture (9.68%). There were statistically significant differences in the number of prior rhinoplasty procedures, infection history, and preoperative ROE scores among the three groups, with no differences in sex ratio, age, kinds of initial implant materials, and postoperative ROE scores. Almost all patients achieved satisfactory outcomes after the revision surgery designed by different classifications. CONCLUSION: The authors have established a new classification system and treatment algorithm for contracted noses based on the change in pathological anatomy of nose, which is effective for guiding the treatment of contracted noses with good results.

Step-Nucleation In Situ Self-Repair to Prepare Rollable Large-Area Ultrathin MOF Membranes.

Ultrathin membranes with ultrahigh permeance and good gas selectivity have the potential to greatly decrease separation process costs, but it requires the practical preparation of large area membranes for implementation. Metal-organic frameworks (MOFs) are very attractive for membrane gas separation applications. However, to date, the largest MOF membrane area reported in the literature is only about 100 cm2 . In the present study, a new step-nucleation in situ self-repair strategy is proposed that enables the preparation of large-area (2400 cm2 ) ultrathin and rollable MOF membranes deposited on an inexpensive flexible polymer membrane support layer for the first time, combining a polyvinyl alcohol (PVA)-metal-ion layer and a pure metal-ion layer. The main role of the pure metal-ion layer is to act as the main nucleation sites for MOF membrane growth, while the PVA-metal-ion layer acts as a slow-release metal-ion source, which supplements MOF crystal nucleation to repair any defects occurring. Membrane modules are necessary components for membrane applications, and spiral-wound modules are among the most common module formats that are widely applied in gas separation. A 4800 cm2 spiral-wound membrane module was successfully prepared, demonstrating the practical implementation of large-area MOF membranes.

Contamination characteristics and potential health risk of brominated flame retardants in paddy soils and rice plants around a typical e-waste recycling site in south China.

Brominated flame retardants (BFRs) are widely used in various productions. As typical BFRs, polybrominated diphenyl ethers (PBDEs) are prohibited because of their toxicity and persistence. Some of the alternatives to PBDEs, new brominated flame retardants (NBFRs), have also been found in the environment and some have assigned hazardous properties and were categorized as persistent. In this study, a typical e-waste dismantling area was chosen as the study area, and the soil and rice samples were collected from the paddy fields around the circular economy park in Guiyu, China. The contaminations of PBDEs and NBFRs in soils and rice plants were detected, and the health risks associated with consumption and exposure to the environment were calculated as well. The concentrations of ∑PBDEs and ∑NBFRs in soil ranged from 283 to 928 µg/kg and 54.7-437 µg/kg, respectively. In rice plants, the majority of BFRs were concentrated in the following order: root > leaf > stem > grain. Additionally, only the PBT exhibited a stronger bioaccumulation ability in rice with the bioconcentration factors more than 1.00. The results of the health quotient calculation shown that BDE-47 might have an impact on people's health that only the HQ of BDE-47 in the soil was higher than 1.00, while there had no significant health risk in grain of BFRs. We believe that our work could assist researchers in investigating and revealing the human health effects of BFRs in soil and rice.

Biochar supported nanoscale zero-valent iron for the kinetics removal and mechanism of decabromodiphenyl ethane in the sediment.

The extensive applications of decabromodiphenyl ethane (DBDPE), a novel brominated flame retardant, have induced its accumulation in sediment, which may have a great negative impact on the ecological environment. In this work, the biochar/nano-zero-valent iron materials (BC/nZVI) were synthesized to remove DBDPE in the sediment. Batch experiments were carried out to investigate the influencing factors of the removal efficiency, and kinetic model simulation and thermodynamic parameter calculation were performed. The degradation products and mechanisms were probed. The results indicated that the addition of 0.10 g·g-1 BC/nZVI to the sediment with an initial concentration of 10 mg·kg-1 DBDPE could remove 43.73% of DBDPE during 24 h. The water content of the sediment was a critical factor in the removal of DBDPE, which was optimal at 1:2 of sediment to water. The removal efficiency and reaction rate were enhanced by increasing dosage, water content, and reaction temperature or decreasing initial concentration of DBDPE based on the fitting results of the quasi-first-order kinetic model. Additionally, the calculated thermodynamic parameters suggested that the removal process was a spontaneously and reversibly endothermic reaction. The degradation products were further determined by GC-MS, and the mechanisms were presumed that DBDPE was debrominated to produce octabromodiphenyl ethane (octa-BDPE). This study provides a potential remediation method for highly DBDPE-contaminated sediment by using BC/nZVI.

Cyantraniliprole seed treatment effectively controls wireworms (Pleonomus canaliculatus Faldermann) and white grubs (Anomala corpulenta Motschulsky) in maize fields.

Wireworms and white grubs are destructive underground pests in maize fields in China. Cyantraniliprole has good control effect on coleoptera pests. Here, we evaluated the toxicity of cyantraniliprole to the second instar larvae of Anomala corpulenta Motschulsky and third-instar of larvae of Pleonomus canaliculatus Faldermann and the effects of sublethal concentrations on the activity of antioxidant and detoxification enzymes. We also explored the efficacy of cyantraniliprole on underground pests under indoor and field conditions. The LC50 of cyantraniliprole for the third instar larvae of P. canaliculatus was 23.3712 mg/L, and that for the second instar larvae of A. corpulenta was 5.9715 mg/L. Cyantraniliprole can activate the activity of superoxide dismutase (SOD), peroxidase (POD), and glutathione S-transferase (GST) to different degrees at a sublethal dose. According to the pot experiment and the control efficacy test in the field, the indoor control effect of cyantraniliprole seed treatment on P. canaliculatus and white grubs was approximately 80%, and the maximum increase in yield achieved through cyantraniliprole application was approximately 15% in the field efficacy test. Cyantraniliprole has a strong control effect on wireworms and white grubs, so it can be used to treat seeds to control underground pests in maize fields.

Legacy and novel brominated flame retardants in a lab-constructed freshwater ecosystem: Distribution, bioaccumulation, and trophic transfer.

The extensive utilization of both legacy and novel brominated flame retardants (BFRs) leads to high environmental concentrations, which would be bioaccumulated by organisms and further transferred through the food webs, causing potential risks to humans. In this study, five BFRs, that showed high detection frequencies and concentrations in sediments from an e-waste dismantling site in Southern China, namely 2,3,4,5,6-pentabromotoluene (PBT), hexabromobenzene (HBB), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), decabromodiphenyl ethane (DBDPE), and decabromodiphenyl ether (BDE209), were selected as target pollutants in the lab-constructed aquatic food web as part of a micro-ecosystem, to investigate their distribution, bioaccumulation, and trophic transfer patterns. The significant correlations between different samples in the food web indicated that the dietary uptake appeared to influence the levels of BFRs in organisms. Significant negative correlations were observed between the trophic level of organisms and the lipid-normalized concentrations of BTBPE and DBDPE, indicating the occurrence of trophic dilution after 5-month exposure. However, the average values of bioaccumulation factors (BAFs) were from 2.49 to 5.17 L/kg, underscoring the importance of continued concern for environmental risks of BFRs. The organisms occupying higher trophic levels with greater bioaccumulation capacities may play a pivotal role in determining the trophic magnification potentials of BFRs. This research provides a helpful reference for studying the impacts of feeding habits on bioaccumulation and biomagnification, as well as for identifying the fate of BFRs in aquatic environment.

ZIF-62 glass foam self-supported membranes to address CH4/N2 separations.

Membranes with ultrahigh permeance and practical selectivity could greatly decrease the cost of difficult industrial gas separations, such as CH4/N2 separation. Advanced membranes made from porous materials, such as metal-organic frameworks, can achieve a good gas separation performance, although they are typically formed on support layers or mixed with polymeric matrices, placing limitations on gas permeance. Here an amorphous glass foam, agfZIF-62, wherein a, g and f denote amorphous, glass and foam, respectively, was synthesized by a polymer-thermal-decomposition-assisted melting strategy, starting from a crystalline zeolitic imidazolate framework, ZIF-62. The thermal decomposition of incorporated low-molecular-weight polyethyleneimine evolves CO2, NH3 and H2O gases, creating a large number and variety of pores. This greatly increases pore interconnectivity but maintains the crystalline ZIF-62 ultramicropores, allowing ultrahigh gas permeance and good selectivity. A self-supported circular agfZIF-62 with a thickness of 200-330 µm and area of 8.55 cm2 was used for membrane separation. The membranes perform well, showing a CH4 permeance of 30,000-50,000 gas permeance units, approximately two orders of magnitude higher than that of other reported membranes, with good CH4/N2 selectivity (4-6).

Metal-Organic Framework Crystal-Glass Composite Membranes with Preferential Permeation of Ethane.

Metal-organic framework (MOF) glass is an easy to process and self-supported amorphous material that is suitable for fabricating gas separation membranes. However, MOF glasses, such as ZIF-62 and ZIF-4 have low porosity, which makes it difficult to obtain membranes with high permeance. Here, a self-supported MOF crystal-glass composite (CGC) membrane was prepared by melt quenching a mixture of ZIF-62 as the membrane matrix and ZIF-8 as the filler. The conversion of ZIF-62 from crystal to glass and the simultaneous partial melting of ZIF-8 facilitated by the melt state of ZIF-62 make the CGC membrane monolithic, eliminating non-selective grain boundaries and improving selectivity. The thickness of CGC membrane can be adjusted to fabricate a membrane without the need of a support substrate. CGC membranes exhibit a C2 H6 permeance of 41 569 gas permeation units (GPU) and a C2 H6 /C2 H4 selectivity of 7.16. The CGC membrane has abundant pores from the glassy state of ZIF-62 and the crystalline ZIF-8, which enables high gas permeance. ZIF-8 has preferential adsorption for C2 H6 and promotes C2 H6 transport in the membrane, and thus the GCG membrane exhibits ultrahigh C2 H6 permeance and good C2 H6 /C2 H4 selectivity.