Lamellar Membranes Research Articles

Using deep eutectic solvents for the in-situ synthesis of graphene-metal nanohybrids and nanocomposite membranes for dye desalination

Deep eutectic solvents (DESs) have recently gained much attention as an environmentally green solvent for different chemical reactions such as materials development. In this study, we used choline chloride/ethylene glycol DES to synthesize different graphene oxide (GO) based nanohybrids such as DES/GO-Fe2O3, DES/GO-Fe3O4, DES/GO-Ag, DES/GO-Au, and DES/GO-TiO2 by reducing the metal precursors to their associated nanoparticles and conjugating them onto the GO surface. Different physical and chemical characterization techniques such as TEM, SEM-EDS, XRD, Raman, and FTIR confirmed the successful preparation of these nanohybrids and their properties. Among the synthesized nanohybrids, DES-GO/TiO2 was selected for the preparation of ultrafast lamellar nanofiltration membrane with self-cleaning properties. The filtration performance of the DES-GO/TiO2 membranes with different GO:TiO2 ratios, i.e., (4:1), (1:1), and (1:4), has been assessed to indicate the effect of TiO2 content on the performance of the membranes filtration. Also, the role of membrane loadings, i.e., 50, 250, and 400 mg/m2 was studied on the water permeance, and dye and salt rejections of the synthesized membranes. DES/GO-TiO2(1:4) membrane with 50 mg/m2 was able to provide the highest water permeance of 200.6 ± 1.7 LMH/Bar and 98.3 ± 1.2% of EB dye rejection while providing very low Na2SO4 salt rejection of 4.1 ± 0.2% indicating its potential effectiveness for selective dye/salt separation.

The ROCK‐inhibitor ripasudil suppresses the expression of extracellular matrix proteins in Fuchs endothelial corneal dystrophy

AbstractPurpose: Fuchs endothelial corneal dystrophy (FECD) is characterized by a progressive loss of human corneal endothelial cells (HCEC) and excess deposition of extracellular matrix (ECM). As FECD pathophysiology involves Rho‐associated kinase (ROCK) signalling activation, we investigated the effect of various ROCK inhibitors on the expression of ECM proteins and proteolytic enzymes using ex vivo and in vitro models.Methods: Endothelial cell‐Descemet membrane lamellae (DM) from donor corneas (n = 20) and FECD patients (n = 100) undergoing Descemet membrane endothelial keratoplasty were used as ex vivo model. A human corneal endothelial cell line (HCEC‐12) served as in vitro model. Rho‐ROCK signalling pathway components and the effects of the ROCK inhibitors ripasudil (10/30 μM), Y‐27632 (10/30 μM), and netarsudil (1 μM) on the expression of ECM proteins and proteolytic enzymes were analysed, with or without addition of transforming growth factor β1 (TGFβ1, 5 ng/ml), using quantitative real‐time PCR and Western Blot analysis.Results: Constitutive expression of components of the Rho‐ROCK signalling pathway was higher in DM specimens from FECD patients compared to DM from normal donors. Stimulation with all three ROCK inhibitors significantly downregulated the expression of ECM genes, such as collagen 3 alpha 1 (COL3A1) and fibronectin 1 (FN1), in both FECD and normal DM as well as in HCEC‐12, compared to untreated controls, with ripasudil showing the most significant effect. Downregulation of COL1A1 and FN1 by ripasudil was verified on protein level as well. Ripasudil also suppressed the TGFβ‐induced expression and phosphorylation of downstream molecules of the TGFβ pathway (SMAD2) as well as of the Rho‐ROCK pathway (MLC2). Ripasudil further upregulated gene expression of proteolytic enzymes, e.g. matrix metalloproteinase 1 (MMP1) and MMP3.Conclusions: These findings suggest that inhibition of ROCK signalling in FECD patients may have a beneficial effect by suppressing expression and stimulating turnover of abnormal ECM components.

Topologically Programmed Graphene Oxide Membranes with Bioinspired Superstructures toward Boosting Osmotic Energy Harvesting

AbstractThe emergence of lamellar nanofluidic membranes offers feasible routes for developing highly efficient, mechanically robust, and large‐scale devices for osmotic energy harvesting. However, inferior ion permeability associated with their relatively long channels limits ionic flux and restricts their output performance. Herein, a superstructured graphene oxide membrane is developed to allow programmable topological variation in local geometry and contain laminar spaces inside. Such deliberate design offers excess specific area as well as nanofluidic channels to modulate transmembrane ionic transportation while concomitantly retaining similar nanoconfined environment in contrast to planar ones, leading to considerable enhancement of ionic permeability without compromising selectivity. This can be highly favorable in terms of osmotic energy harvesting, where the superstructured membranes offer a power output much higher than those of conventional planar ones. Besides, the superstructure design also endows the resulting membranes with benign biofouling resistance, which can be crucial to their long‐term usage in converting osmotic energy. This study highlights the importance of membrane topographies and presents a general design concept that could be extended to other nanoporous membranes to develop high‐performance nanofluidic devices.

Two-Dimensional Nanofluidic Membranes with Intercalated In-Plane Shortcuts for High-Performance Blue Energy Harvesting.

Two-dimensional nanofluidic membranes offer great opportunities for developing efficient and robust devices for ionic/water-nexus energy harvesting. However, low counterion concentration and long pathway through limited ionic flux restrict their output performance. Herein, it is demonstrated that rapid diffusion kinetics can be realized in two-dimensional nanofluidic membranes by introducing in-plane holes across nanosheets, which not only increase counterion concentration but also shorten pathway length through the membranes. Thus, the holey membranes exhibited an enhanced performance relative to the pristine ones in terms of osmotic energy conversion. In particular, a biomimetic multilayered membrane sequentially assembled from pristine and holey sections offers an optimized combination of selectivity and permeability, therefore generating a power density up to 6.78Wm-2 by mixing seawater and river water, superior to the majority of the state-of-the-art lamellar nanofluidic membranes. This work highlights the importance of channel morphologies and presents a general strategy for effectively improving ion transport through lamellar membranes for high-performance nanofluidic devices.

Researching proton conduction behavior at subzero temperature of lamellar anhydrous proton exchange membranes

For proton exchange membranes (PEMs), many studies have been going into the anhydrous PEMs with the working temperature exceeding 110 °C and the humidified PEMs below 80 °C. However, the PEMs fracture can cause cold start failure while the fuel cell vehicles are exposed to a colder climate for a long-time parking. In this study, low temperature PEMs (LTPEMs) with the lamellar structure was constructed through the well-ordered dispersion of Kevlar nanofibers, thioglycollic acid capping cadmium telluride (CdTe) nanocrystals and polyurethane (PU) polymer, expecting to enhance the mechanical property and improve the proton conductivity at subzero temperature. The successful preparation of the LTPEMs with spin coating technique and layer by layer self-assembly technique was determined by the structure analysis and the property measurement. The compact microstructure was constructed owing to electrostatic attraction and intermolecular hydrogen bonding. In the prepared (Kevlar/CdTe)25/(PU/CdTe)100 membrane, Kevlar nanofibers provided the support and PU molecular chains guaranteed enough flexibility. Furthermore, a massive amount of CdTe nanocrystals could tolerate low temperature condition, which was derived from the high proton conductivity at subzero temperature. Specifically, the (Kevlar/CdTe)25/(PU/CdTe)100/PA membrane exhibited the proton conductivity values of (2.23 ± 0.39) × 10−2 S/cm at −30 °C, (6.59 ± 0.15) × 10−2 S/cm at 0 °C and (1.73 ± 0.04) × 10−1 S/cm at 30 °C. Most importantly, the fine proton conductivity stability was revealed from the proton conductivity values of 3.72 × 10−2 S/cm at −30 °C after a thirty-cycle heating/cooling process and 3.53 × 10−2 S/cm at −30 °C after a 1020 h non-stop test. Furthermore, there was a slight decrease on the tensile stress with PA molecules doping owing to the compact microstructure.

Fast hydrogen purification through graphitic carbon nitride nanosheet membranes

Two-dimensional graphitic carbon nitride (g-C3N4) nanosheets are ideal candidates for membranes because of their intrinsic in-plane nanopores. However, non-selective defects formed by traditional top-down preparation and the unfavorable re-stacking hinder the application of these nanosheets in gas separation. Herein, we report lamellar g-C3N4 nanosheets as gas separation membranes with a disordered layer-stacking structure based on high quality g-C3N4 nanosheets through bottom-up synthesis. Thanks to fast and highly selective transport through the high-density sieving channels and the interlayer paths, the membranes, superior to state-of-the-art ones, exhibit high H2 permeance of 1.3 × 10−6 mol m−2 s−1 Pa−1 with excellent selectivity for multiple gas mixtures. Notably, these membranes show excellent stability under harsh practice-relevant environments, such as temperature swings, wet atmosphere and long-term operation of more than 200 days. Therefore, such lamellar membranes with high quality g-C3N4 nanosheets hold great promise for gas separation applications.

Heterogeneous Two-dimensional lamellar Ti3C2Tx membrane for osmotic power harvesting

Osmotic energy generated from salinity gradients has been recognized as a novel blue energy source. Membrane-based reverse electrodialysis (RED) is a promising strategy for harvesting electric power from salinity difference. However, practical RED process often suffers from the low energetic efficiency due to the inherent ion concentration polarization phenomenon. Here, a heterogeneous two-dimensional lamellar Ti3C2Tx membrane with asymmetric geometry and charge properties was designed. The diode-like transport behavior with unidirectional ion conduction was observed, suggesting a preferential transport direction in the Ti3C2Tx hetero-nanochannel. When applied as the osmotic energy generators, the heterogeneous Ti3C2Tx membranes produced a maximum output power density of 16 W/m2 on mixing the natural brine and river water, higher than the commercialization benchmark (5 W/m2). Theoretical calculations confirmed that the asymmetric membrane architecture achieved a balance between effectively weakening the concentration polarization and maintaining the high ion selectivity. This study is a significant step forward in the field of designing artificial nanofluidic membranes and highly efficient osmotic energy conversion systems.

MOF lamellar membrane-derived LLTO solid state electrolyte for high lithium ion conduction

Inorganic superionic conductor has been widely studied for potential application in all-solid-state lithium battery due to its high bulk ionic conductivity. However, the large grain boundary resistance and large thickness resulted from the poor film-forming ability, restricting its actual ionic conductivity. Inspired by the excellent film-forming ability and ultrathin thickness of 2D lamellar membrane, we reported an 11 μm-thick MOF lamellar membrane derived LLTO electrolyte (MLLTO). The electrolyte is prepared by impregnating LLTO precursors into the pores and interlayer channels of MOF lamellar membrane, followed by in situ sintering. It is demonstrated that the confined effect of interlayer channel in MOF lamellar membrane regulates the growth and arrangement of LLTO crystal, affording reduced grain boundary resistance. The porous structure of MOF nanosheet permits the construction of vertical Li+ transfer pathways between adjacent layers. Finally, MLLTO achieves a high ionic conductivity of 1.19 × 10−4 S cm−1 and ionic conductance of 0.215 S at room temperature, much higher than those of conventional LLTO electrolytes. The Li/MLLTO/Li symmetrical cell can stably cycle for 1000 h from 0.1 to 0.4 mA cm−2 at 60 °C without obvious polarization. The LFP/Li battery displays discharge capacity of 149.6 mAh g−1 at 0.5C after 200 cycles with low capacity decay of 0.04% per cycle.

Facile Ionization of the Nanochannels of Lamellar Membranes for Stable Ionic Liquid Immobilization and Efficient CO2 Separation.

Two-dimensional (2D) lamellar membranes, with highly ordered nanochannels between the adjacent layers, have revealed potential application prospects in various fields. To separate gases with similar kinetic diameters, intercalation of a functional liquid, especially an ionic liquid (IL), into 2D lamellar membranes is proved to be an efficient method due to the capacity of imparting solubility-based separation and sealing undesired defects. Stable immobilization of a high content of liquid is challenging but extremely required to achieve and maintain high separation performance. Herein, we describe the intercalation of a typical IL, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]), into the ionized nanochannels of sulfonated MXene lamellar membranes, where the sulfonate groups are anchored onto MXene nanosheets through a facile method based on metal-catechol chelating chemistry. Thanks to the intrinsic benefits of MXene as building blocks and the decorated sulfonate groups, the optimal membrane possesses adequate interlayer spacing (∼1.8 nm) and high IL uptake (∼47 wt %) and therefore presents a CO2 permeance of 519 GPU and a CO2/N2 selectivity of 210, outperforming the previously reported liquid-immobilized lamellar membranes. Moreover, the IL loss rate of the membrane within 7 days at elevated pressure (5 bar) is measured to be significantly decreased (from 43.2 to 9.0 wt %) after growing sulfonate groups on the nanochannel walls, demonstrating the excellent IL storage stability.

Attapulgite Nanorods Incorporated MXene Lamellar Membranes for Enhanced Decontamination of Dye Wastewater.

Due to its unique physical and chemical properties, MXene has recently attracted much attention as a promising candidate for wastewater treatment. However, the low water permeation flux of MXene membrane remains a challenge that has not been fully solved. In this study, attapulgite was used to increase the flux of MXene membrane through a facile one-pot method, during which the MXene nanosheets were self-assembled while being intercalated by the attapulgite nanorods to finally form the composite membranes. Under optimal conditions, an increase of water permeation flux of 97.31% could be observed, which was attributed to the broadened nano-channel upon the adequate intercalation of attapulgite nanorods. Its permeation flux and rejection rate for methylene blue (MB) were further studied for diverse applications. In contrast to bare MXene, the permeation flux increased by 61.72% with a still high rejection rate of 90.67%, owing to the size rejection. Overcoming a key technique barrier, this work successfully improved the water permeability of MXene by inserting attapulgite nanorods, heralding the exciting prospects of MXene-based lamellar membrane in dye wastewater treatment.

Tuneable molecular selective boron nitride nanosheet ultrafiltration lamellar membrane for dye exclusion to remediate the environment.

Smart tuning of the membrane's porous nanostructures offers an effective strategy for creating state-of-the-art, high-performance separation membranes. In aqueous solution, polyethylene glycol (PEG) grafted boron nitride PEGX-g-(f-BN) nanosheets exhibit high permeance and excellent molecular sieving. The molecular selectivity of the PEGX-g-(f-BN) lamellar membrane is controlled by the nanopores, which can be tuned by modulating the interplanar spacing between the nanosheets. Herein, the interplanar spacing of h-BN nanosheets is enhanced in the range of 0.334-0.348nm through grafting different molecular weight PEG. Moreover, the grafted PEG instigates a synergistic effect on the nanosheets in two ways. Firstly, through PEG intercalation, the interlayer spacing of the (002) plane could be adjusted without significant deterioration to the hexagonal crystallographic structure. Secondly, intercalated PEG in BN nanosheets reflects in terms of improved h-BN wettability through transformation to hydrophilic surface characteristics (small contact angle of 36-39°). The fabricated PEGX-g-(f-BN) lamellar membrane acquires stable and interconnected nanopores and nanochannels with an average pore diameter of 1.36-2.19nm. Permeance-exclusion trade-off manipulation through methodical approaches of PEGX-g-(f-BN) decoration thickness and interplanar spacing is exploited to build a better understanding of water transport behavior. PEGX-g-(f-BN) lamellar membranes show unprecedented permeance of ∼1253Lm-2 h-1 bar-1 with a steady methyl blue (MB) exclusion of 98.9% even in different pH conditions.

Functionalized Graphene Oxide-Based Lamellar Membranes with Tunable Nanochannels for Ionic and Molecular Separation.

Graphene oxide (GO)-based membranes with tunable microstructure and controlled nanochannels have attracted an increasing interest for various applications in wastewater treatment, desalination, gas separation, organic nanofiltration, etc. However, they showed limited use in water desalination due to their lower stability and separation efficiency. In this work, a class of two-dimensional (2D) GO lamellar membranes have been prepared with controlled pores for efficient and fast separation of ions and dye molecules. The GO membranes are fucntionalized with a star-like 6-armed poly(ethylene oxide) using the simple amidation route under mild conditions. The as-prepared covalently cross-linked networks are chemically steady in aqueous medium and show remarkable selectivity (∼100%) for several probe molecules and 10–100 higher permeance than those of the reported GO-based membranes. Further, such membranes are also used for salt separation and show more than 80% rejection for Pb2+ and Ni2+ salts. Moreover, a 1360 nm-thick membrane shows >99% rejection for NaCl with a good water permeance of up to 120 L m–2 h–1 bar–1. Additionally, these membranes are stable for more than 20 days under different conditions.

Assembly of MXene/ZnO heterojunction onto electrospun poly(arylene ether nitrile) fibrous membrane for favorable oil/water separation with high permeability and synergetic antifouling performance

The two dimensional MXene nanosheets lamellar membranes have emerged as the promising candidates for oil/water separation. However, to deal with the large-scale discharge of complicated oily wastewater (including oils, organics, microorganism, etc), developing advanced membrane materials with high permeate flux and enhanced antifouling is still big challenge. Herein, the MXene/ZnO heterojunction was prepared by electrostatic attraction, which was modified by tannic acid (TA) and further self-assembled onto the poly (arylene ether nitrile) (PEN) fibrous mat to construct the multi-functional separation membrane (ZnO/M-TA@PEN fibrous composite membrane). In the hierarchical functional layer, the improved hydrophilicity of TA and the hierarchical micro-/nano-roughness build by ZnO NPs contributed to the super-hydrophilic/underwater super-oleophobic feature (WCA = 0°, UOCA>152°), leading to high separation efficiency and ultra-low oil adhesion. Uniquely, the decoration of ZnO NPs achieved the “intercalation effect” and effectively tuned the interlayer spacing between MXene nanosheets, which conquered the stacking problem of MXene nanosheets lamellar membrane and greatly enhanced the permeation flux of membrane. For separating various oil emulsions, the resulting ZnO/M-TA@PEN fibrous composite membrane displayed superior emulsion separation flux (1815.34 ± 44.73–2053.35 ± 42.62 L/m2·h) and separation efficiency (>99.4%), even in high-temperature and salty environments. More importantly, the heterojunction structure of MXene/ZnO hybrid endowed the fibrous composite membrane with enhanced antibacterial ability and photocatalytic self-cleaning performance toward the degradation of methylene blue, which realized the synergetic antifouling and favorable cycling ability of the fibrous composite membrane. This combination of anti-fouling and high permeability renders the membrane as attractive candidate for dealing with the oily wastewater containing multicomponent pollutants.

Study on Spacing Regulation and Separation Performance of Nanofiltration Membranes of GO.

Graphene oxide (GO) membranes have attracted significant attention in the field of water processing in recent years due to their unique characteristics. However, few reports focus on both membrane stability and the “trade-off” effect. In this study, a series of aliphatic diamines (1, 2-ethylenediamine, 1, 4-butanediamine, and 1, 6-hexamethylenediamine) of covalent crosslinked GO were used to prepare diamine-modified nanofiltration membranes, BPPO/AX-GO, with adjustable layer spacing using the vacuum extraction–filtration method. Moreover, Ax-GO-modified nanofiltration membranes modified with adipose diamine had higher layer spacing, lower mass-transfer resistance, and better stability. When the number of carbon atoms was 5, the best layer spacing was reached, and when the number of carbon atoms was greater than 4, the modified membrane nanosheets more easily accumulated. With the increase in layer spacing, the water flux of the composite film increased to 26.27 L/m2·h·bar. Meanwhile, adipose diamine crosslinking significantly improved the stability of GO films. The interception sequence of different valence salts in the composite membrane was NaCl > Na2SO4 > MgSO4, and the rejection rate of bivalent salts was higher than that of monovalent salts. The results can provide some experimental basis and research ideas for overcoming the “trade-off” effect of a lamellar GO membrane.

Two-dimensional MWW-type zeolite membranes for efficient dye separation and water purification

Two-dimensional (2D) zeolites provide inspiring opportunities for the exploitation of ultra-thin molecular sieve membranes, but it is rarely applied in water treatment membranes. Exfoliated 2D MWW-type nanosheets in liquid hydroxyl-terminated polybutadiene (HTPB) were assembled into the lamellar MH membranes by vacuum filtration. Various techniques were employed to characterize the surface chemical composition and morphology of the MH membranes. The typical ordered layer-like structure built by the stack of MWW nanosheets mainly contributed to the performance of the MH membrane, and the guest role of a small amount of residual HTPB has also been confirmed. The obtained MH membrane exhibited a water permeance of 11.3 L·m−2·h−1·bar−1 with above 99.5 % rejection for Evans Blue (EB). In particular, the rejection of negatively charged dyes with a molecular size greater than 1.5 nm essentially remained above 90.0 %. Moreover, the lamellar MH membrane possessed excellent physicochemical stability. Excellent rejection was guaranteed at different pressures, pH, and successive cross-flow operations. Although there is still a demand for improvement in terms of permeance, the successful preparation of 2D zeolite lamellar membranes fully demonstrates the promising potential of 2D zeolite nanosheets in water purification.

Two-Dimensional Membranes with Highly Charged Nanochannels for Osmotic Energy Conversion.

Inadequate mass transportation of semipermeable membranes causes poor osmotic energy conversion from salinity-gradient. Here, the lamellar graphene oxide membranes (GOMs) constructed with numerous fusiform-like nanochannels, that are pre-filled with negatively charged polyanion electrolytes, to both enhance the ion permeability and ion selectivity of the membrane for energy harvest from the salinty gradient, were developed. The as-prepared membrane achieved the maximum output power density of ∼4.94 W m-2 under a 50 fold salinity gradient, which is 3.5 fold higher than that of pristine GOM. The enhancement could be ascribed to the synergistic impact of the expanded nanochannels and the enhanced space charge density. Via feeding with the artificial salinity water and monovalent cation electrolytes, the system could realise the power output up to 14.7 W m-2 and 34.1 W m-2 , respectively. Overall, this material design strategy could provide an alternative concept to effectively enhance ion transport of other two-dimensional (2D) membranes for specific purposes.

Design lamellar GO membrane based on understanding the effect of functional groups distributed in the port on desalination

The lamellar membranes have been considered as one of the most promising candidates for seawater desalination owing to their well-defined 2D nanochannels for fast water permeation and excellent ions rejection. However, it was difficult to directly determine the influence of different functional groups on the desalination performance through experiments. In this work, the –COOH/–CH3 were introduced to the port of lamellar GO membranes, and the effect of functional group distributed in the port of membranes was investigated via non-equilibrium molecular dynamic simulation (NEMD). It was found that the water flux rate passing through the lamellar GOY-X membranes with –COOH/–CH3 group modified in their port was slightly higher than that in systems without port modification. Some lamellar membranes shown excellent water flux rate and ion rejection ions were designed by taking advantage of functional group distributed in the port of membranes and surfaces of pore channel.

Matrix free polymer nanocomposites from amphiphilic hairy nanoparticles: Solvent selectivity and mechanical properties

Matrix free polymer nanocomposite of spherical nanoparticles with shells made of amphiphilic homopolymer was studied in molecular dynamics experiments. The amphiphilic homopolymer was presented as sequence of identical monomer units, each containing two beads having different affinity to solvent. The self-assembly in solution of such hairy nanoparticles was studied depending on solvent quality and selectivity for different polymer concentrations. Two of the most characteristic morphologies were identified and described. The first one is a structure resembling a mixture of sea hedgehogs. There is a nanoparticle in the core of a hedgehog, and the spines consist of several grafted chains. Hedgehogs float freely, do not aggregate with other nanoparticles, their solutions have a low moduli of elasticity and viscosity up to a fairly high polymer concentration. The second morphology is thin membrane lamellae assembled from amphiphilic homopolymers. In this case, the nanoparticles are joined into a single network-like aggregate at very low polymer concentrations. Such networks possess a unique porous structure and demonstrate high elasticity and viscosity moduli. These findings could be useful for molecular design of smart materials, that are able to reversibly assemble, disintegrate on request and repair damage by self-healing mechanism. • Nanoparticles, coated with amphiphilic homopolymers, are studied. • Such nanoparticles can self-assemble either into gels or into “hedgehogs” mixture. • Gels have membrane-like, porous structure, and demonstrate elastic and viscous response. • Core-shell filaments preserve aggregation and favor uniform distribution of “hedgehogs”. • Structure type is determined by solvent quality and selectivity.

PNPLA1-Mediated Acylceramide Biosynthesis and Autosomal Recessive Congenital Ichthyosis.

The stratum corneum of the epidermis acts as a life-sustaining permeability barrier. Unique heterogeneous ceramides, especially ω-O-acylceramides, are key components for the formation of stable lamellar membrane structures in the stratum corneum and are essential for a vital epidermal permeability barrier. Several enzymes involved in acylceramide synthesis have been demonstrated to be associated with ichthyosis. The function of patatin-like phospholipase domain-containing protein 1 (PNPLA1) was a mystery until the finding that PNPLA1 gene mutations were involved in autosomal-recessive congenital ichthyosis (ARCI) patients, both humans and dogs. PNPLA1 plays an essential role in the biosynthesis of acylceramide as a CoA-independent transacylase. PNPLA1 gene mutations cause decreased acylceramide levels and impaired skin barrier function. More and more mutations in PNPLA1 genes have been identified in recent years. Herein, we describe the structural and functional specificity of PNPLA1, highlight its critical roles in acylceramide synthesis and skin barrier maintenance, and summarize the PNPLA1 mutations currently identified in ARCI patients.

2D lamellar membrane with nanochannels synthesized by bottom-up assembly approach for the superior photocatalytic hydrogen evolution

Designing nanoscale photocatalysts to improve photocatalytic efficiency is a popular research topic. However, for wide application and friendly environment, achieving good dispersion and multiple recycling of photocatalysts at the nanoscale remains challenging. Herein, a general bottom-up assembly method is proposed for designing a class of two-dimensional lamellar membranes (2DLMs) for photocatalytic applications. A bismuth oxychloride (BiOCl) nanosheet (BN) was used as a demo photocatalyst to construct a 2DLM via self-stacking. The designed BiOCl membrane (BM) exhibited excellent physical properties including flexibility, mechanical strength (tensile strength = 15.75 MPa, fracture strain = 0.056%), and translucence, as well as superior photocatalytic performance with excellent recycling stability and reusability. The photocatalytic hydrogen evolution performance of BM was 2.5-fold that of BN particles dispersed in an aqueous solution. Further theoretical calculations revealed that a BM with appropriately sized nanochannels can accelerate water transport, and the main horizontal channel size of the BM (3.13 nm) is very close to the size of the ideal water transport nanochannel. Furthermore, the confined internal space reduces the number of hydrogen bonds for water molecules within the nanochannels, thereby enhancing the interfacial reaction rate and photocatalytic efficiency. This study presents a simple bottom-up assembly method to design photocatalysts with further improved performance.