Oxide Membranes Research Articles

Aromatic Amine-Supported N-Functionalization of Nanoscale-Thick Graphene Oxide Membranes for Preferential Adsorption of Strontium Ions from Aqueous Solutions

Aromatic Amine-Supported N-Functionalization of Nanoscale-Thick Graphene Oxide Membranes for Preferential Adsorption of Strontium Ions from Aqueous Solutions

Electrochemical identification and quantification of through‐plane proton channels in graphene oxide membranes

Stacked graphene oxide (GO) proton membranes are promising candidates for use in energy devices due to their proton conductivity. Identification of through‐plane channels in these membranes is critical but challenging due to their anisotropic nature. Here, we present an electrochemical reduction method for identifying and quantifying through‐plane proton channels in GO membranes. The simplicity lies in the operando optical observation of the change in contrast as GO is electrochemically reduced. Here, we find three proton‐dominated three‐phase interfaces, which are critical for the reduction reactions of GO membranes. Based on these findings, a method is proposed to identify and quantify through‐plane channels in stacked GO proton membranes using a simple three‐electrode device in combination with real‐time imaging of the membrane surface.

Electrochemical identification and quantification of through-plane proton channels in graphene oxide membranes.

Stacked graphene oxide (GO) proton membranes are promising candidates for use in energy devices due to their proton conductivity. Identification of through-plane channels in these membranes is critical but challenging due to their anisotropic nature. Here, we present an electrochemical reduction method for identifying and quantifying through-plane proton channels in GO membranes. The simplicity lies in the operando optical observation of the change in contrast as GO is electrochemically reduced. Here, we find three proton-dominated three-phase interfaces, which are critical for the reduction reactions of GO membranes. Based on these findings, a method is proposed to identify and quantify through-plane channels in stacked GO proton membranes using a simple three-electrode device in combination with real-time imaging of the membrane surface.

In-situ confined preparation of COF@GO nanofiltration membranes for high-efficiency dye removal

Graphene oxide membrane (GOM) possesses ultrafast and tunable two-dimensional water transport pathways, making it an ideal candidate for nanofiltration separation of dye wastewater. However, GOM also faces great challenges such as poor aqueous stability, collapse of non-oxygenated regions under high pressure, and limitations imposed by trade-off effects. In this study, covalent organic frameworks (COFs) were in-situ formed within GOM interlayers and on membrane surface to enlarge interlayer spacings and enhance hydrophilicity of GOM simultaneously via a two-step method including monomer retention in GOM and in-situ confined interfacial polymerization of COFs. Fourier transformation infrared spectroscopy (FT-IR) and X-ray photoelectron spectrometry (XPS) results confirmed the successful synthesis of COF on GOM surface, which enhanced membrane surface hydrophilicity and bridged the split defects of GOM. According to X-ray diffraction measurements (XRD) and scanning electron microscope (SEM) results, COF@GO membranes possessed enlarged interlayer spacings and increased thickness of selective layer, which indicated the successful intercalation of COF into GO interlayer. COF@GO-50 membrane exhibited an ultrahigh pure water permeability (PWP) of 148.1 L/(m2·h·bar), with 99.0 % rejection for direct red 80 (DR80) aqueous solution and 9.6 % NaCl rejection. The ultrahigh water permeance might be ascribed to the enlarged interlayer pathways, the shortened vertical pathways provided by in-plane pores of COF nanosheets, and enhanced water adsorption capacity due to enhanced membrane hydrophilicity. Moreover, COF@GO nanofiltration membrane demonstrated excellent anti-fouling properties and long-term stability in 30h continuous operation, maintaining considerable separation efficiency under harsh conditions. This work provides a straightforward and applicable strategy to simultaneously enlarge interlayer spacings and enhance surface hydrophilicity of GOM via in-situ confined preparation of COFs, achieving ultrahigh water permeance and overcoming the trade-off effect between permeability and selectivity of GOM.

Machine Learning‐Guided Design and Synthesis of Eco‐Friendly Poly(ethylene oxide) Membranes for High‐Efficacy CO2/N2 Separation

AbstractMachine learning (ML)‐guided polymer design and synthesis will enable the next‐generation membrane material discovery for CO2 capture. Herein, ML is leveraged to establish a structure‐performance relationship for the eco‐friendly poly(ethylene oxide) (PEO) membrane and guide its design for high‐efficacy CO2/N2 separation. Through a rational fragment representation method and knowledge sharing across membranes fabricated by different methods, the precise prediction of CO2/N2 separation performance for PEO membranes with high Pearson correlation coefficients (0.973 for permeability and 0.875 for selectivity) despite data scarcity is demonstrated. Expertise knowledge and external monomer databases are then utilized in a human‐in‐the‐loop workflow to effectively explore high‐performance PEO membranes in the design space. Several discovered thermally crosslinked PEO membranes achieve CO2/N2 separation performances close to the 2019 Robeson upper bound, which are promising for practical large‐scale carbon capture applications. Model interpretation techniques are employed to provide data‐driven insights into the design of PEO membranes for high‐efficacy CO2/N2 separation. Further life cycle assessment results reveal the outstanding advantage of discovered PEO membranes in terms of environmental friendliness. The work highlights the enormous potential of ML in expediting the discovery of high‐performance carbon capture membrane materials.

Spatial regulation of NMN supplementation on brain lipid metabolism upon subacute and sub-chronic PM exposure in C57BL/6 mice

BackgroundAtmospheric particulate matter (PM) exposure-induced neuroinflammation is critical in mediating nervous system impairment. However, effective intervention is yet to be developed.ResultsIn this study, we examine the effect of β-nicotinamide mononucleotide (NMN) supplementation on nervous system damage upon PM exposure and the mechanism of spatial regulation of lipid metabolism. 120 C57BL/6 male mice were exposed to real ambient PM for 11 days (subacute) or 16 weeks (sub-chronic). NMN supplementation boosted the level of nicotinamide adenine dinucleotide (NAD+) in the mouse brain by 2.04 times. This augmentation effectively reduced neuroinflammation, as evidenced by a marked decrease in activated microglia levels across various brain regions, ranging from 29.29 to 85.96%. Whole brain lipidomics analysis revealed that NMN intervention resulted in an less increased levels of ceramide (Cer) and lysophospholipid in the brain following subacute PM exposure, and reversed triglyceride (TG) and glycerophospholipids (GP) following sub-chronic PM exposure, which conferred mice with anti-neuroinflammation response, improved immune function, and enhanced membrane stability. In addition, we demonstrated that the hippocampus and hypothalamus might be the most sensitive brain regions in response to PM exposure and NMN supplementation. Particularly, the alteration of TG (60:10, 56:2, 60:7), diacylglycerol (DG, 42:6), and lysophosphatidylcholine (LPC, 18:3) are the most profound, which correlated with the changes in functional annotation and perturbation of pathways including oxidative stress, inflammation, and membrane instability unveiled by spatial transcriptomic analysis.ConclusionsThis study demonstrates that NMN intervention effectively reduces neuroinflammation in the hippocampus and hypothalamus after PM exposure by modulating spatial lipid metabolism. Strategies targeting the improvement of lipid homeostasis may provide significant protection against brain injury associated with air pollutant exposure.

Thin-Layer TiO2 Membrane Fabrication by Condensed Layer Deposition.

A novel approach to the fabrication of thin-film supported metal oxide membranes was investigated. Nanocoatings were obtained by the condensed layer deposition of TiO2 on tubular microporous supports, applying multiple consecutive layers of TiO2/polyaniline. The surface, cross-sectional structure, and morphology of the materials were investigated by electron microscopy. Their membrane-related properties were explored by permeability measurements, rejection, and fouling analysis, using polyethylene glycol (PEG) as test molecules. The SEM images showed that TiO2 was successfully deposited on the surface, creating a layer with partial coverage of the support after each layer was deposited; consequently, the permeability of the membranes decreased gradually. Overall, the results of the flux and permeability of the membranes confirmed the coating. The transmembrane pressure (TMP) increased with each coating layer, while the rejection of the membrane showed gradual improvement.

Cytotoxic and Apoptotic Effects of Green Synthesized Silver Nanoparticles via Reactive Oxygen Species-Mediated Mitochondrial Pathway in Human Breast Cancer Cells.

Due to their exceptional physicochemical features, green synthesized silver nanoparticles (AgNPs) have been of considerable interest in cancer treatment. In the present study, for the first time, we aimed to green synthesize AgNPs from Euphorbia retusa and explore their anticancer potential on human breast cancer (MCF-7) cells. First, the green synthesized AgNPs (EU-AgNPs) were well characterized by UV-visible spectroscopy, Fourier transmission infrared (FTIR) spectrum, XRD, scanning and transmission electron microscopy (SEM and TEM), and EDX techniques. The characterization data exhibited that EU-AgNPs were spherical in shape and crystalline in nature with an average size of 17.8 nm. FTIR results established the presence of active metabolites in EU-AgNPs. Second, the anticancer effect of EU-AgNPs was evaluated against MCF-7 cells by MTT and neutral red uptake (NRU) assays. Moreover, morphological changes, ROS production, MMP, and apoptotic marker genes were also studied upon exposure to cytotoxic doses of EU-AgNPs. Our results showed that EU-AgNPs induce cytotoxicity in a concentration-dependent manner, with an IC50 value of 40 μg/mL. Morphological changes in MCF-7 cells exposed to EU-AgNPs also confirm their cytotoxic effects. Increased ROS and decreased MMP levels revealed that EU-AgNPs induced oxidative stress and mitochondrial membrane dysfunction. Moreover, ROS-mediated apoptosis was confirmed by elevated levels of proapoptotic marker genes (p53, Bax, caspase-3, and caspase-9) and reduced levels of an antiapoptotic gene (Bcl-2). Altogether, these findings suggested that EU-AgNPs could induce potential anticancer effects through ROS-mediated apoptosis in MCF-7 cells.

Study of the Effect of Manganese on The Structural and Optical Properties of Sno2 Membranes

The effect of manganese addition on precipitated tin dioxide on quartz was studied using the pulsed laser method if the X-ray diffraction results showed that the pure tin oxide membrane has a polycrystalline structure and a quaternary phase, with growth in the crystalline directions (110), (101), (200), and (211) and the predominant ones were (101). Using a high-benefit electron scanning microscope (FE-SEM), the results showed that the addition of manganese smearing in small proportions significantly affected the surface nature and grain size, as the surface uniformity and grain size increased with increasing the percentage of distortion. Through optical examinations through the permeability spectrum of thin films of pure and tinged tin oxide, a gradual increase in permeability with an increase in the concentration of impurities, reaching high values ranging between 80-90%. As for the energy gap, the energy gap for manganese-inlaid membranes has been increased from 3.33 eV for the pure membrane to 3.57 eV. The sensing properties of these membranes were studied as a function of time at temperatures between 50-200 °C .

Experimental and theoretical assessment of bioinspired next-generation intercalated graphene oxide-based ceramic membranes for oil-in-water emulsion separation

2D graphene oxide (GO) membranes are gaining prominence for water reclamation from oily wastewater. Unresolved challenges include low membrane permeance from tight sheets and fouling during separation. In this work, a bioinspired Arabic gum (AG) was used as an intercalated agent with the help of glutaraldehyde to improve the GO membranes’ permeation and fouling resistance. The 2D-laminated separating layer is crafted through a self-assembling innovative approach utilizing pressurized dead-end assembly. The Arabic gum intercalated graphene oxide-modified ceramic membrane (AGIGO-CM) appeared superhydrophilic and underwater (UW) superoleophobic with a UW oil contact angle (UWOCA) of 156.1 ± 1.2°. The membrane prepared with 1 mg of AGIGO (AGIGO-1-CM) offers a flux of 17 times higher than pristine graphene oxide (p-GO) while maintaining a separation efficiency of >99% during the separation of the oil-in-water emulsions. Molecular dynamics (MD) simulations showed AG intercalation expanding the interlayer distance by up to 20 Å, with AGIGO having a higher fractional free volume (FFV) of 0.986 compared to p-GO’s 0.599. AGIGO-CM displayed lower interfacial formation energy (EIFE) of −1865.2 kcal/mol versus −765.5 kcal/mol for p-GO, indicating easier separation. It is further supported by the substantial interfacial thickness of 148 Å for AGIGO-CM compared to 53.0 Å for the p-GO membranes. AGIGO-CM showed minimal fouling, retaining >99% separation efficiency for 6 h. Compared to p-GO-CM, AGIGO-CM flux decreased by only 17.84% versus 44.72%. AGIGO-CM exhibited stability even in acidic and basic environments, showcasing its potential for high performance.

Hydrogen Sulfide and 5‐Aminolevulinic Acid Synergistically Enhance Drought Tolerance in Tomato (Solanum lycopersicum L.)

ABSTRACTEnhancing crop drought tolerance is crucial for food security amid climate change. This study examines how 5‐aminolevulinic acid (ALA) and hydrogen sulfide (H2S) can improve drought resilience in tomato plants, which are essential for sustainable food production. Drought stress was induced using 12% PEG‐6000. Plants were pre‐treated with 25 mg L−1 ALA and 0.1 mg L−1 hypotaurine (HT), followed by 0.2 mM sodium hydrosulfide (NaHS) treatment to assess the effects on plant physiological effects over 10 days. Drought stress reduced plant dry weight, chlorophylls (a and b), Fv/Fm, leaf water potential, and relative water content, while increasing glycine betaine (GB) and proline levels. Additionally, drought stress elevated NADPH oxidase (NOX) and glycolate oxidase (GOX) activities, inducing oxidative stress and membrane damage. ALA and NaHS enhanced plant growth, photosynthesis, proline, GB, ALA content, ATP synthase, and ATPase activities, while mitigating NOX and GOX activities, thereby reducing and H2O2 radicals. ALA alone boosted L‐DES activity, promoting H2S accumulation. However, ALA + HT reduced H2S levels, compromising ALA's efficacy. NaHS with ALA + HT reinstated positive effects by restoring H2S levels. Biochemical assays confirmed ALA and NaHS promoted H2S accumulation, bolstering antioxidants, mitigating lipid peroxidation, suggesting their drought resilience potential in tomatoes.

Solid phase epitaxy of SrRuO3 encapsulated by SrTiO3 membranes

Solid phase epitaxy (SPE) has been widely employed for various thin-film materials, making it valuable for industrial applications due to its scalability. In complex oxides, SPE has been limited to a few materials because of the challenges in maintaining stoichiometric control during growth, particularly when volatile phases are present at high temperatures. Here, we investigate the impact of encapsulation layers on the SPE of complex oxides, using SrRuO3 (SRO) as a model system. An amorphous SRO layer was deposited on a SrTiO3 (STO) substrate, followed by the transfer of a single-crystalline STO membrane as an encapsulation layer in order to suppress the evaporation of volatile species (RuO2) during the SPE process. Whereas both encapsulated and unencapsulated SRO layers were successfully crystallized, the unencapsulated films suffered a substantial loss of Ru ions—exceeding 20%—compared to their encapsulated counterparts. This loss of Ru ions led to a loss of metallicity in the unencapsulated SRO layers, whereas the encapsulated layers retained their metallic ferromagnetic properties. This study demonstrates that the encapsulation provided by oxide membranes effectively suppresses stoichiometric loss during SPE, presenting a new strategy in stabilizing a broader class of functional oxides as epitaxial thin films.

Boosting the H2/CO2 and H2/N2 selectivities of a graphene oxide membrane by shrinking the membrane interlayer spacing via thermal treatment

Graphene oxide (GO) membranes have been widely studied and used for gas separation processes, but some structural changes are necessary to guarantee high membrane selectivities. The thermal reduction process stands out for reducing the interlayer channel size of the GO nanosheets to improve the molecular sieving mechanism. Herein, thermally annealed GO layers were deposited on the outer surface of porous alumina hollow fiber substrates and the produced composite membranes were tested for selective hydrogen (H2) separations. The influence of the thermal annealing process at different mild temperatures (80 and 160 °C) on the characteristics of the GO structure was investigated towards the improvement of the membrane efficiency for H2 separation. ATR-FTIR results confirmed the elimination of oxygenated groups, and XRD analyses showed the GO interlayer space decreased from 8.71 to 7.38 Å after the thermal annealing process at 160 °C. The GO thermally annealed membrane presented an H2 permeance of 2032.47 ± 101.69 GPU and an H2/N2 selectivity of 12.16 ± 0.30, which is 315% greater than the selectivity of the pristine GO membrane. Hence, the application of the thermal reduction method to produce GO membranes with greater selectivities is a viable alternative to deal with gas separation processes.

Dietary plants for oral cancer prevention and therapy: A review of preclinical and clinical studies.

Oral cancer is a disease with high mortality and rising incidence worldwide. Although fragmentary literature on the anti-oral cancer effects of plant products has been published, a comprehensive analysis is lacking. In this work, a critical and comprehensive evaluation of oral cancer preventative or therapeutic effects of dietary plants was conducted. An exhaustive analysis of available data supports that numerous dietary plants exert anticancer effects, including suppression of cell proliferation, viability, autophagy, angiogenesis, invasion, and metastasis while promoting cell cycle arrest and apoptosis. Plant extracts and products target several cellular mechanisms, such as the reversal of epithelial-to-mesenchymal transition and the promotion of oxidative stress and mitochondrial membrane dysfunction by modulation of various signaling pathways. These agents were also found to regulate cellular growth signaling pathways by action on extracellular signal-regulated kinase and mitogen-activated protein kinase, inflammation via modulation of cyclooxygenase (COX)-1, COX-2, and nuclear factor-κB p65, and metastasis through influence of cadherins and matrix metalloproteinases. In vivo studies support these findings and demonstrate a decrease in tumor burden, incidence, and hyperplastic and dysplastic changes. Clinical studies also showed decreased oral cancer risk. However, high-quality studies should be conducted to establish the clinical efficacy of these plants. Overall, our study supports the use of dietary plants, especially garlic, green tea, longan, peppermint, purple carrot, saffron, tomato, and turmeric, for oral cancer prevention and intervention. However, further research is required before clinical application of this strategy.

Different functional groups cross-linked graphene oxide membranes for proton exchange membrane fuel cell

The graphene oxide (GO) membrane treated by ozone, GOL, exhibits a relatively high conductivity, but its mechanical strength cannot be maintained due to severe swelling. To further improve the conductivity while suppressing the swelling, the free-standing GO membrane was subjected to ozone treatment and subsequently modified by crosslinking agents with oxygen functional groups, i.e., glyoxal (GLX) and oxalic acid (OXA). The modified membranes, GLX/GOL and OXA/GOL, successfully reduced the swelling and increased the conductivity to provide an excellent power output of a fuel cell at 30 °C due to the increased oxygen functional groups and the carbon defects. Furthermore, OXA/GOL exhibited a significant stability at elevated temperatures. At 50 °C, the through-plane conductivity and power output increased to 23.5 mS cm−1 and 317 mW cm−2, respectively. This is considered to be due to the relatively high thermal stability of the carboxy group added by the OXA modification.

Ecophysiological, transcriptomic and metabolomic analyses shed light on the response mechanism of Bruguiera gymnorhiza to upwelling stress

Mangroves, due to their unique habitats, endure dual stressors from land to ocean and ocean to land directions. While extensive researches have been conducted on land-ocean stressors, studies on ocean-land stressors like upwelling are considerably scarce. In this study, ecophysiological, transcriptome, and metabolome analyses were conducted to determine the responses of mangrove plant (Bruguiera gymnorhiza, B. gymnorhiza) to upwelling stress. The results suggested that upwelling stress in B. gymnorhiza induces oxidative stress and membrane damage, which are mitigated by the synergistic actions of antioxidant enzymes and osmoprotectants. Transcriptomic and metabolomic analyses revealed that upregulated genes related to oxidation-reduction and carbohydrate metabolism, along with accumulated metabolites such as amino acids, lipids, phenols, and organic acids, contribute to enhancing antioxidant capacity and maintaining osmotic balance. Further analysis identified key KEGG pathways involved in the response to upwelling stress, including amino acid metabolism, carbohydrate and energy metabolism, flavonoid biosynthesis, and plant hormone signal transduction. These findings provide vital information into the multi-level response mechanisms of mangrove plants to upwelling stress.

Structurally Defined Amphiphilic AAO Membranes Using UV-Assisted Thiol-Yne Chemistry: Applications in Anti-Counterfeiting and Electronics.

In this study, we fabricate and characterize amphiphilic anodic aluminum oxide (AAO) membranes using UV-triggered thiol-yne click reactions and photomasks for various innovative applications, including driven polymer nanopatterns, anti-counterfeiting, and conductive pathways. Specifically, we synthesize 10-undecynyl-terminated-AAO membranes and subsequently prepare amphiphilic AAO membranes with superhydrophilic and superhydrophobic regions. Various analytical methods, including grazing angle X-ray photoelectron spectroscopy (GIXPS), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), nanofocused synchrotron X-ray techniques (nano-XRD and nano-XRF), and water contact angle measurements, confirm the modifications and distinct properties of the modified areas. This work achieves a series of applications, such as driven polymer nanopatterns, solvent- and light-triggered anti-counterfeiting, and region-selective conductive pathways using silver paint with lower resistivity. Besides, the amphiphilic AAO membrane exhibits successful stability, durability, and reusability. To sum up, this study highlights the versatility and potential of amphiphilic AAO membranes in advanced material design and smart applications.

Enhanced removal of antibiotic-resistant bacteria and resistance genes by three-dimensional electrochemical process using MgFe2O4-loaded biochar as both particle electrode and catalyst for peroxymonosulfate activation

In this study, MgFe2O4-loaded biochar (MFBC) was used as a three-dimensional particle electrode to active peroxymonosulfate (EC/MFBC/PMS) for the removal of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs). The results demonstrated that, under the conditions of 1.0 mM PMS concentration, 0.4 g/L material dosage, 5 V voltage intensity, and MFBC preparation temperature of 600 °C, the EC/MFBC600/PMS system achieved complete inactivation of E. coli DH5α within 5 min and the intracellular sul1 was reduced by 81.5 % after 30 min of the treatment. Compared to EC and PMS alone treatments, the conjugation transfer frequency of sul1 rapidly declined by 92.9 % within 2 min. The cell membrane, proteins, lipids, as well as intracellular and extracellular ARGs in E. coli DH5α were severely damaged by free radicals in solution and intracellular reactive oxygen species (ROS). Furthermore, up-regulation was observed in genes associated with oxidative stress, SOS response and cell membrane permeability in E. coli DH5α, however, no significant changes were observed in functional genes related to gene conjugation and transfer mechanisms. This study would contribute to the underlying of PMS activation by three-dimensional particle electrode, and provide novel insights into the mechanism of ARB inactivation and ARGs degradation under PMS advanced oxidation treatment.

2D Carbonaceous Materials for Molecular Transport and Functional Interfaces: Simulations and Insights.

ConspectusCarbon-based two-dimensional (2D) functional materials exhibit potential across a wide spectrum of applications from chemical separations to catalysis and energy storage and conversion. In this Account, we focus on recent advances in the manipulation of 2D carbonaceous materials and their composites through computational design and simulations to address how the precise control over material structure at the atomic level correlates with enhanced functional properties such as gas permeation, selectivity, membrane transport, and charge storage. We highlight several key concepts in the computational design and tuning of 2D structures, such as controlled stacking, ion gating, interlayer pillaring, and heterostructure charge transfer.The process of creating and adjusting pores within graphene sheets is vital for effective molecular separation. Simulations show the power of controlling the offset distance between layers of porous graphene in precisely regulating the pore size to enhance gas separation and entropic selectivity. This strategy of controlled stacking extends beyond graphene to include covalent organic frameworks (COFs) such as covalent triazine frameworks (CTFs). Experimental assembly of the layers has been achieved through electrostatic interactions, thermal transformation, and control of side chain interactions.Graphene can interface with ionic liquids in various forms to enhance its functionality. A computational proof-of-concept showcases an ion-gating concept in which the interaction of anions with the pores in graphene allows the anions to dynamically gate the pores for selective gas transport. Realization of the concept has been achieved in both porous graphene and carbon molecular sieve membranes. Ionic liquids can also intercalate between graphene layers to form interlayer pillaring structures, opening the slit space. Grand canonical Monte Carlo simulations show that these structures can be used for efficient gas capture and separation. Experiments have demonstrated that the interlayer space can be tuned by the density of the pillars and that, when fully filled with ionic liquids and forming a confined interface structure, the graphene oxide membrane achieves much higher selectivity for gas separations. Moreover, graphene can interface with other 2D materials to form heterostructures where interfacial charge transfers take place and impact the function. Both ion transport and charge storage are influenced by both the local electric field and chemical interactions.Fullerene can be used as a building block and covalently linked together to construct a new type of 2D carbon material beyond a one-atom-thin layer that also has long-range-ordered subnanometer pores. The interstitial sites among fullerenes form funnel-shaped pores of 2.0-3.3 Å depending on the crystalline phase. The quasi-tetragonal phases are shown by molecular dynamics simulations to be efficient for H2 separation. In addition, defects such as fullerene vacancies can be introduced to create larger pores for the separation of organic solvents.In conclusion, the key to imputing functions to 2D carbonaceous materials is to create new interactions and interfaces and to go beyond a single-atom layer. First-principles and molecular simulations can further guide the discovery of new 2D carbonaceous materials and interfaces and provide atomistic insights into their functions.

Anomalous mass transfer behavior of organic molecules in crosslinked graphene oxide membranes induced by intermolecular forces

Membrane-based technology has a wide application for many separation practices, nevertheless, the precise separation of organic molecules using a membrane remains challenging. To get a deeper understanding of the nanoconfined mass transport of the organic molecules, pristine and crosslinked graphene oxide (GO) membranes were synthesized, and their transport properties were systemically studied. With m-phenylenediamine (MPD) crosslinked, the flux of the organics across the GO-MPD membrane was approximately 5-fold lower than that of the pristine GO membrane, though the GO-MPD membrane retains a relatively large pore size. Computational simulations implied the occurrence of strong intermolecular forces between the organics and the GO-MPD membrane, which significantly affected the partitioning and diffusion of the organics. We propose that the synergetic effect of “capacity and strength” needs to be considered when organic transport impacts are examined. By combining a low sorption capacity with strong intermolecular forces between organic molecules and the membrane, the transport of organic molecules across the membrane could be slowed down or inhibited, and vice versa. Our work offers a more comprehensive framework at the nanoscale that deepens the understanding of organic molecule mass transfer, which aids in the designing of high-selective membrane materials for separation practices involving organic molecules.