Rapid Water Transport Research Articles

Phase‐Separated Polyzwitterionic Hydrogels with Tunable Sponge‐Like Structures for Stable Solar Steam Generation

AbstractSolar steam generation (SSG) through hydrogel‐based evaporators has shown great promise for freshwater production. However, developing hydrogel‐based evaporators with stable SSG performance in high‐salinity brines remains challenging. Herein, phase‐separated polyzwitterionic hydrogel‐based evaporators are presented with sponge‐like structures comprising interconnected pores for stable SSG performance, which are fabricated by photopolymerization of sulfobetaine methacrylate (SBMA) in water‐dimethyl sulfoxide (DMSO) mixed solvents. It is shown that driven by competitive adsorption, the structures of the resulting poly(sulfobetaine methacrylate) (PSBMA) hydrogels can be readily tuned by the volume ratio of DMSO to achieve phase separation. The optimized phase‐separated PSBMA hydrogels, combining the unique anti‐polyelectrolyte effects of polyzwitterionic hydrogels, demonstrate a rapid water transport capability in brines. After introducing photothermal polypyrrole particles on the surface of the phase‐separated PSBMA hydrogel evaporators, a stable water evaporation rate of ≈2.024 kg m−2 h−1 and high solar‐to‐vapor efficiency of ≈97.5% in a 3.5 wt.% brine are obtained under simulated solar light irradiation (1.0 kW m−2). Surprisingly, the evaporation rates remain stable even under high‐intensity solar irradiation (2.0 kW m−2). It is anticipated that the polyzwitterionic hydrogel evaporators with sponge‐like porous structures will contribute to developing SSG technology for high‐salinity seawater applications.

Ring- and diffuse-porous tree species from a cold temperate forest diverge in stem hydraulic traits, leaf photosynthetic traits, growth rate and altitudinal distribution.

In cold and humid temperate forests, low temperature, late frost and frequent freeze-thaw cycles are the main factors limiting tree growth and survival. Ring- and diffuse-porous tree species differing in xylem anatomy coexist in these forests, but their divergent adaptations to these factors have been poorly explored. To fill this knowledge gap, we compared four ring-porous and four diffuse-porous tree species from the same temperate forest in Northeast China by quantifying their leaf and stem functional traits, their stem growth rates using tree ring analysis and their resistance to cold represented by upper altitude species distribution borders from survey data. We found that the ring-porous trees were characterized by traits related to more rapid water transport, carbon gain and stem growth rates than those of the diffuse-porous species. Compared with the diffuse-porous species, the ring-porous species had a significantly higher shoot hydraulic conductance (Ks-shoot, 0.52 vs 1.03kgm-1s-1MPa-1), leaf photosynthetic rate (An, 11.28 vs 15.83μmolm-2s-1), relative basal area increment (BAIr, 2.28 vs 0.72cmyear-1) and stem biomass increment (M, 0.34 vs 0.09kgyear-1m-1). However, the observed upper elevational distribution limit of the diffuse-porous species was higher than that of the ring-porous species and was associated with higher values of conservative traits, such as longer leaf life span (R2=0.52). Correspondingly, BAIr and M showed significant positive correlations with acquisitive traits such as Ks-shoot (R2=0.77) and leaf photosynthetic rate (R2=0.73) across the eight species, with the ring-porous species occurring at the fast-acquisitive side of the spectrum and the diffuse-porous species located on the opposite side. The observed contrasts in functional traits between the two species groups improved our understanding of their differences in terms of growth strategies and adaptive capabilities in the cold, humid temperate forests.

Biomimetic vertically aligned aerogel with synergistic photothermal effect enables efficient solar-driven desalination

Taking sustainable solar energy for efficient rapid clean water production is eagerly desired to overcome the water shortage issue. However, great challenges remain in constructing short water transport channels and enhancing sunlight utilization efficiency. Herein, a biomimetic solar-driven interfacial evaporator with rapid water transport and high photothermal conversion efficiency inspired by natural-trees was successfully developed, via engineer vertically aligned hydrophilic sodium alginate (SA) aerogels while hierarchically assembled MXene interwoven carbon nanotube (CNT) networks as micro/nano light absorb layer. Due to the synergistic photothermal effect between 2D MXene nanosheets and 1D CNT with multiple reflective nanostructure and strong light-absorption over a broad spectrum, and super-hydrophilic SA with highly oriented water transport channels, which enables fast water/vapor transport while utilizing solar energy efficiently. Vertically aligned aerogel exhibits an excellent water evaporation performance which as high as 2.416 kg m−2 h−1 (deducting dark conditions) and remarkable solar energy utilizing efficiency of 90.56 %, which are extremely higher than that of most reported desalination devices. Furthermore, the solar-driven evaporator also exhibits strong antibacterial properties and long-term operation stability. The biomimetic vertically aligned aerogel with excellent water evaporation and light utilization efficiency holds great promise for high-performance water purification and desalination applications. Synopsis statementResearch on the rapid clean water production from wastewater/seawater with high solar energy utilization efficiency has become a hot topic, and solar-driven desalination offers a sustainable solution to meet water demands. This study reports a biomimetic solar-driven interfacial evaporator with oriented water transport nanochannel and multi-reflective solar absorber for efficient clean water production.

A highly efficient and sustainable photoabsorber in solar-driven seawater desalination and wastewater purification.

Producing freshwater from seawater and wastewater is of great importance through interfacial solar steam generation (ISSG). Herein, the three-dimensional (3D) carbonized pine cone, CPC1, was fabricated via a one-step carbonization process as a low-cost, robust, efficient, and scalable photoabsorber for the ISSG of seawater as well as a sorbent/photocatalyst for use in wastewater purification. Taking advantage of the large solar-light-harvesting ability of CPC1 due to the presence of carbon black layers on the 3D structure, its inherent porosity, rapid water transportation, large water/air interface, and low thermal conductivity, a conversion efficiency of 99.8% and evaporation flux of 1.65 kg m-2 h-1 under 1 sun (kW m-2) illumination were achieved. After carbonization of the pine cone, its surface becomes black and rough, which leads to an increase in its light absorption in the UV-Vis-NIR region. The photothermal conversion efficiency and evaporation flux of CPC1 did not change significantly during 10 evaporation-condensation cycles. CPC1 exhibited good stability under corrosive conditions without significant change in its evaporation flux. More importantly, CPC1 can be used to purify seawater or wastewater by the removal of organic dyes as well as by the reduction of polluting ions, like nitrate ions in sewage.

Janus aramid nanofiber aerogel incorporating plasmonic nanoparticles for high-efficiency interfacial solar steam generation

Interfacial solar steam generation (ISSG) is a novel and potential solution to global freshwater crisis. Here, based on a facile sol-gel fabrication process, we demonstrate a highly scalable Janus aramid nanofiber aerogel (JANA) as a high-efficiency ISSG device. JANA performs near-perfect broadband optical absorption, rapid photothermal conversion and effective water transportation. Owning to these features, efficient desalination of salty water and purification of municipal sewage are successfully demonstrated using JANA. In addition, benefiting from the mechanical property and chemical stability of constituent aramid nanofibers, JANA not only possess outstanding flexibility and fire-resistance properties, but its solar steaming efficiency is also free from the influences of elastic deformations and fire treatments. We envision JANA provides a promising platform for mass-production of high-efficiency ISSG devices with supplementary capabilities of convenient transportation and long-term storage, which could further promote the realistic applications of ISSG technology.

Boosting water evaporation via continuous formation of a 3D thin film through triple-level super-wicking routes.

Capillary-fed thin-film evaporation via micro/nanoscale structures has attracted increasing attention for its high evaporation flux and pumpless liquid replenishment. However, maximizing thin-film evaporation has been hindered by the intrinsic trade-off between the heat flux and liquid transport. Here, we designed and fabricated nanostructured micro-steam volcanoes on copper surfaces featuring triple-level super-wicking routes to overcome this trade-off and boost water evaporation. The triple-level super-wicking routes enable the continuous formation of a 3D thin film for highly efficient evaporation by continuous self-driven liquid replenishment and extending the thin-film region. The micro-steam volcanoes increased the surface area by 225%, improving the evaporation rate by 141%, with a rapid self-pumping water transport speed up to 80 mm s-1. A remarkable solar-driven water evaporation rate of 3.33 kg m-2 h-1 under one sun vertical incidence was achieved, which is among the highest reported values for metal-based evaporators. When attached to electric-heating plates, the evaporator realized an electrothermal evaporation rate of 12.13 kg m-2 h-1. Moreover, it can also be used for evaporative cooling with enhanced convective heat transfer, reaching a 36.2 °C temperature reduction on a heat source with a heat flux of 6 W cm-2. This study promises a general strategy for designing thin-film evaporators with high efficiencies, low costs, and multi-functional compatibilities.

Gradient heating induced better balance among water transportation, salt resistance and heat supply in a high performance multi-functional solar-thermal desalination device.

Solar-driven desalination (SDD) is a promising technology for addressing water scarcity. However, how to overcome the trade-off between water transportation and heat supply of the evaporator to achieve a high evaporation rate and good salt tolerance simultaneously remains a challenge. Here, a novel all-in-one multi-functional SDD evaporator undergoing gradient heating is used. This evaporator incorporates a hydrophilic PDA (polydopamine)@CNT(carbon nanotube)/PVA (polyvinyl alcohol) aerogel with vertically aligned structures as the water evaporation layer, enabling rapid water transportation. Surrounding the evaporation layer, there is a photothermal hydrophobic CCP (cotton/CNT/polydimethylsiloxane) film that serves as the heating layer, enhancing the heat supply to the evaporation layer. This innovative design strikes a favorable balance between water transportation and heat supply, facilitating high evaporation rates and good salt tolerance simultaneously, while also maximizing electricity generation. Due to the wettability difference between the evaporation layer (PVA aerogel) and heating layer (CCP film), a record stable temperature gradient of nearly 70 °C was formed between the CCP film and the PVA aerogel under 1 sun irradiation, so that heat on the high-temperature CCP film was continuously transferred to the low-temperature aerogel through its thermal conductive network, leading to a high evaporation rate of 6.96 kg m-2 h-1 under 1 sun irradiation in 5.0 wt% sodium chloride (NaCl) brine (higher than the world average seawater salinity (3.5 wt%)). Meanwhile, high flux directional flow of brine generated 130 mV stable voltage and 120 μA circuit current. Furthermore, the evaporator illustrates good stability for consecutive 7 days of testing and shows industry-leading comprehensive performance of SDD in actual use. More importantly, it was tested in real Bohai seawater under weak natural light, and fresh water generated can meet the recommended daily intake of water for 2.6 households and the simultaneously generated voltage reaches above 60 mV. In addition, the evaporator exhibits good adsorption capacity for heavy metals and dye molecules. This simple and universal solar evaporation structure is suitable for the assembly of gradient thermal structures for most solar thermal materials reported in the literature, which provides a new route for maximizing the use of solar energy for freshwater and electricity generation.

Covalent organic framework-immobilized wood membrane for efficient, durable, and high-flux nanofiltration

Covalent organic frameworks (COFs) are promising for the construction of nanofiltration membranes owing to their uniform, ordered channel structures and high chemical stability. However, developing a low-cost strategy for fabricating COF-based nanofiltration membranes and increasing the long-term stability of the membranes are challenging. Here, we developed a TpPa-wood membrane through the in-situ formation of massive imine COFs on the top surface of a wood block for the rapid and efficient nanofiltration-based separation of organic pollutants. The numerous hydroxyl groups of cellulose in wood provided nucleation sites for the growth of dense, defect-free COFs with a diameter of 1.8 nm. The nano porous COFs enabled efficient separation, while the long and low-tortuosity channels of wood with a diameter of 10–30 μm facilitated rapid water transport and augmented the mechanical robustness of the membrane. Therefore, the prepared TpPa-wood membrane showed an outstanding separation efficiency of ∼97.0% toward organic pollutants such as dyes and pharmaceutical molecules at a flux rate of 600 L m−2 h−1. In addition, the TpPa-wood membrane exhibited excellent stability at a wide pH range (3–11) and over continuous filtration for 48 h. The TpPa-wood membrane opens up a new avenue for rapid and efficient nanofiltration by combining the merits of nano porous COFs and biomass with numerous micro-channels and high hydrophilicity.

Building rapid water transport channels within thin-film nanocomposite membranes based on 2D mesoporous nanosheets

The fabrication of novel thin-film nanocomposite (TFN) membranes with superior flux, rejection as well as prolonged stability is being requested by membrane industries for saving energy and cost. In this regard, in the present research work we developed novel TFN membranes using amine-rich synthetic talc (NHST) nanosheets within diethylenetriamine (DETA) and trimesoyl chloride (TMC) monomers over a polydopamine (PDA) coating layer. Different concentrations (0.2–1 %) of NHST nanosheets are applied for the fabrication of TFN membranes and comparatively examined with a thin-film composite (TFC) membrane. In-situ synthesized NHST nanosheet phases are confirmed by several characterization techniques and results are explored in depth. All prepared membranes are well investigated to confirm the incorporation of NHST by several characterization techniques, like FE-SEM, ATR-FTIR, HR-TEM, XPS, PXRD, TGA, and contact angle. It is found that a small amount of NHST doping in the TFN layer considerably improved the performance in the form of permeability and rejection. The developed TFN membranes showed hydrophilic characteristics as confirmed by the contact angle. Water flux performance of TFN membranes was also observed comparatively higher than TFC membranes. Optimized NHST-PDT-TFN2 membrane with NHST concentration 0.5 % resulted in 98.96, 95.35, 93.83 and 21.66 % rejection for Na2SO4, MgSO4, CuSO4 and NaCl salts, respectively together with permeance up to 24.45, 22.72, 26.45 and 30.75 Lm−2h−1b−1. The present research finding concludes that the incorporation of a little quantity of NHST nanosheets in the TFN layer plays a unique potential role in the enhancement of flux and rejection of targeted mineral salts. Additionally, the NHST-PDT-TFN membranes revealed outstanding antibacterial properties signifying that contact with microorganisms does not affect the performance and sustains the fouling resistance. The antifouling study of the membranes concluded that the addition of nanomaterials has led to enhanced antifouling tendency and low irreversible fouling, improving the longevity of the membranes.

Sustainable Interfacial Evaporation System Based on Hierarchical MXene/Polydopamine/Magnetic Phase-Change Microcapsule Composites for Solar-Driven Seawater Desalination.

Solar photothermal-driven interfacial evaporation is a promising technology with great potential for wastewater purification and seawater desalination. However, intermittent solar illumination and salt accumulation are still the major roadblocks of interfacial evaporation in practical applications. Herein, we developed a novel interfacial evaporation system based on the hierarchical MXene/polydopamine (PDA)/magnetic phase-change microcapsule composites (hereafter named "MXene/PDA@TiO2/Fe3O4@C22-HMC") integrated with natural wood. The microcapsule composites were fabricated by microencapsulating n-docosane as a phase-change material (PCM) core in a TiO2/Fe3O4 composite shell and then coating a PDA layer, followed by surface-attaching with MXene nanosheets. The obtained MXene/PDA@TiO2/Fe3O4@C22-HMC exhibits a good optical absorption ability, high heat energy-storage capacity, and good hydrophilicity. This enables the MXene/PDA@TiO2/Fe3O4@C22-HMC-based evaporator to gain a high water evaporation rate of 2.09 kg m-2 h-1 under one-sun illumination. A combination of the microchannels in natural wood and the tiny gap between the microcapsules results in a rapid water transportation within the evaporation system, which effectively resists salt accumulation during the evaporating process. As a result, there was no salt crystal observed from the evaporator surface in a 10 wt % NaCl solution under three-sun illumination for 8 h. More importantly, the introduction of Fe3O4 nanoparticles into the TiO2 shell endows the MXene/PDA@TiO2/Fe3O4@C22-HMC with magnetism, greatly enhancing the reusability and separability of the developed evaporator to undertake multicycle salt accumulation and washing processes for long-term desalination use. The latent heat release of the n-docosane core offers the developed evaporator a large amount of heat energy for continuous evaporation on a semi-cloudy day, increasing the total water production by 1.17 kg m-2 compared to the conventional evaporator without a PCM. This study provides an effective solution for intermittent solar energy utilization and salt accumulation in the solar-driven interfacial evaporation systems of seawater desalination.

High‐Entropy‐Alloy‐Nanoparticles Enabled Wood Evaporator for Efficient Photothermal Conversion and Sustainable Solar Desalination

AbstractHigh‐entropy‐alloy (HEA) nanoparticles with excellent photothermal conversion performances have been proven effective for solar steam generation abilities, but it remains a challenge to fabricate a macroscale evaporator through them. Here, assisting by the unique anisotropic porous structures of balsawood matrixes, a sustainable HEA‐nanoparticles‐balsawood (HEA‐BW) composited evaporator, in which two compositions construct an asymmetric surface wettability that the top surface of HEA nanoparticles acts as a hydrophobic photothermal area, while the bottom hydrophilic surface of balsawood allows for rapid water transportation, is assembled. The most efficient 8‐HEA‐BW realized an average optical absorption greater than 97% over the entire solar spectrum (250–2500 nm) and an excellent evaporation rate of 2.58 kg m−2 h−1 with a surface temperature of 80 °C under one sun irradiation. Surprisingly, a stable solar desalination performance of such composited evaporator can be observed in a 10‐cycles long‐term evaluation of the hypersaline water (20 wt% salinity) with an average evaporation rate of 1.65 kg m−2 h−1.

Rapid transport of water and monovalent ions through ultrathin polyamide nanofilms for highly efficient mono/bivalent ions separation

Defect-free ultrathin polyamide nanofilms enable superior separation performance, which can be prepared by interfacial polymerization (IP) at free oil–water interface (also known as support-free IP). However, the current free IP methods usually suffer from complicated process, or complex equipment. Herein, an easily-manufactured plate-and-frame assembly for free IP was designed for more efficient fabrication of ultrathin membranes. Piperazine (PIP)-based negatively-charged NF membranes were fabricated by this method, combining with introduction of a rigidly-contorted spirobisindane monomer that simultaneously enhanced the mechanical strength, microporosity, and electronegativity of membrane. The resulting defect-free ultrathin membranes not only exhibit super-high Na2SO4 rejection (∼99.7 %), and allow rapid transport of water and monovalent ions, thus leading to a Cl-/SO42- selectivity of up to 240. Furthermore, the polymerization of acyl chloride and macromolecule polyethyleneimine (PEI) at free oil–water interface was also investigated. The resulting positively-charged ultrathin membranes show outstanding calculated monovalent/bivalent cation selectivity (54.8 for Li+/Mg2+, 43.2 for Na+/Mg2+), further demonstrating the effectiveness of ‘thickness reduction’ strategy to enhance ions selectivity. In addition, the cause of different surface charge properties for PIP and PEI membrane system was revealed by molecular simulation.

MOF-Derived nanoarchitectured carbons in wood sponge enable solar-driven pumping for high-efficiency soil water extraction

Soil-water extraction based on interfacial solar-thermal technology is a promising strategy to provide affordable freshwater in remote and poor inland areas. A double-layer solar evaporator is prepared on a wood sponge with a one-step brush-printing coating of zeolitic imidazolate framework-8 (ZIF-8)-derived nanostructured carbon. In this typical architecture, the ZIF-8-derived carbon coating inherits the original porous, dodecahedral framework, thus forming a chapped, rough morphology that synergistically promotes photothermal conversion. Wood sponges manufactured from raw wood offer privileged water-extraction advantages, including an abundance of super hydrophilic channels that ensure efficient bulk-water pumping and steam release. The double-layer solar evaporator shows high sunlight absorbance (∼97.8 %), low thermal conductivity (0.12 W m−1 K−1), stronger capillary force, and rapid water transport (30 cm min−1). Consequently, apparent pure water-evaporation and soil water-extraction rates reach 1.42 and 0.57 kg m-2h−1 under a one-sun light intensity, respectively. Therefore, the ZIF-8-based wood sponge can efficiently achieve interfacial evaporation and soil water extraction, providing a novel pathway for obtaining clean drinking water in arid inland areas.

Finely regulated polyamide membranes with rapid water transport for low-pressure precise nanofiltration

Low-pressure nanofiltration (NF) has evinced huge application prospects for ion/molecule separation. However, current polyamide-based membranes made by highly reactive monomers offer less control in precisely tuning of their pore apertures, leading to a permeability-selectivity trade-off limit. Herein, the usage of amino-piperidine (AP, 4-aminopiperidine: 4AP; 3-aminoapiperidine: 3AP) is proposed as new building block that interfacially polymerizes with trimesoyl chlorides (TMC) onto a nanofibrous hydrogel to fabricate high-performance thin film composite (TFC) membranes. The resultant amino-piperidine thin film composite (AP-TFC) membranes with nodular and bubble-like surface have high hydrophilicity, electronegativity, and moderate crosslinking degree. Introducing an alkane bond length based on the piperidine structure allows to finely augment the free-volume elements of polyamide-based membranes, combined with varying the monomer concentrations. Furthermore, the 4AP-TFC membranes showed an excellent water permeability of 35.0 L m−2 h−1 bar−1 with Na2SO4 rejection above 98.5% when the 4AP concentration was 0.05 w/v%. The 4AP-TFC membrane was also found having a superior sieving capability for antibiotics, attributed to the synergy of size exclusion by well-defined ultra-microporous structure (<0.7 nm) and electrostatic repulsion due to the abundance of surface negative charges. This work provides the guideline of using AP molecules for the fabrication of high-crosslinked TFC membranes with potential applications in low-pressure NF, organic solvent NF, and related water purification.

Molecular architecting of photothermal hydrogels reinforced by polar-porous C2NxO1-x for efficient solar water purification

Solar-powered interfacial evaporation provides a sustainable and effective means of harvesting green energy to relieve the global water scarcity issues. While hydrogel evaporators are effective for purifying the contaminated or saline water, the use of hydrophobic carbon-based light-absorbers that compromises the hydratability and local heat exchange poses an impediment to the evaporation rates. Herein, we propose a concept of using heteroatoms-rich and porous C2NxO1-x as the light absorber for molecular design of hydrogel-based evaporators for solar-powered water purification. The synergy of abundant polar groups within C2NxO1-x and hydratable skeleton (chitosan and polyvinyl alcohol) enables the decline of water evaporation enthalpy and thus facilitates vapor generation. The hydrophilic C2NxO1-x that penetrates hydrogel network enlarges the pore aperture with improved pore interconnectivity, which allows for rapid water transport and sufficient water supply. Importantly, the converted energy was localized to sufficiently power the evaporation of water molecules present in polar pores of C2NxO1-x due to adequate heat exchange. The resultant photothermal hydrogel attains a high evaporation rate of ca. 2.9 kg m−2 h−1 with an ultrahigh ion removal efficiency (99.9 %) in both simulated seawater and complex ionic contaminants under one sun irradiation. This study offers a useful guideline of utilizing hydrophilic porous light-absorber to develop high-performance hydrogel for efficient solar-powered water purification.

Janus Biopolymer Sponge with Porous Structure Based on Water Hyacinth Petiole for Efficient Solar Steam Generation.

Solar-driven steam generation for desalination is a facile, sustainable, and energy-saving approach to produce clean freshwater. However, the complicated fabrication process, high cost, potential environmental impact, and salt crystallization of conventional evaporators limit their large-scale application. Herein, we present a sustainable Janus evaporator based on a biopolymer sponge from the water hyacinth petiole (WHP) for high-performance solar steam generation. The freeze-dried WHP maintained its original porous structure and aligned channels well, and therefore holds the capability for rapid water transport due to strong capillary action. The WHP coated with carbon nanotubes/ethyl cellulose paste on its surface (WHP-C) gains a good photothermal property, thus achieving an efficient solar steam generation with a rate of 1.50 kg m−2 h−1 under 1 sun irradiation. Moreover, the WHP-C after hydrophobic modification by fluorocarbon (WHP-CH) is endowed with high water repellency and exhibits good salt resistance during long-term solar desalination. Additionally, we demonstrate that a stable wet surface that enables efficient water supply and vapor escape is also significant to the successive desalination of a solar evaporator. Our work provides new insights into the high-value utilization of biomass waste, i.e., water hyacinth, and the development of sustainable interfacial solar evaporators for the environmentally friendly production of freshwater.

Fast water transport and molecular sieving through ultrathin ordered conjugated-polymer-framework membranes

The development of membranes that block solutes while allowing rapid water transport is of great importance. The microstructure of the membrane needs to be rationally designed at the molecular level to achieve precise molecular sieving and high water flux simultaneously. We report the design and fabrication of ultrathin, ordered conjugated-polymer-framework (CPF) films with thicknesses down to 1 nm via chemical vapour deposition and their performance as separation membranes. Our CPF membranes inherently have regular rhombic sub-nanometre (10.3 × 3.7 Å) channels, unlike membranes made of carbon nanotubes or graphene, whose separation performance depends on the alignment or stacking of materials. The optimized membrane exhibited a high water/NaCl selectivity of ∼6,900 and water permeance of ∼112 mol m-2 h-1 bar-1, and salt rejection >99.5% in high-salinity mixed-ion separations driven by osmotic pressure. Molecular dynamics simulations revealed that water molecules quickly and collectively pass through the membrane by forming a continuous three-dimensional network within the hydrophobic channels. The advent of ordered CPF provides a route towards developing carbon-based membranes for precise molecular separation.

MXene-doped kapok fiber aerogels with oleophobicity for efficient interfacial solar steam generation

Although the evaporation efficiency of photothermal materials (PMs) in pure water and brine solutions has been extensively studied, there few research on the performance in complex oily wastewater. Herein, a new monolithic solar steam generator derived from kapok fiber-based MXene composite aerogel (named as KFs-MXene) was fabricated by dipping the aerogels (KFs) which composed of kapok fiber and sodium alginate (SA) as substrates in the suspension of MXene. Benefitting from the outstanding light absorption (about 97%), better thermal insulation (thermal conductivity, 0.05039 W m−1 K−1), abundant porosity (95.60%) and rapid water transportation. KFs-MXene show good interfacial solar steam generation (ISSG) performance, resulting in a high water evaporation rate of 1.47 kg m−2h−1 with an outstanding evaporation efficiency of 90.4% under 1 kW m−2 irradiation. To improve the antifouling performance of KFs-MXene, chemically hydrophilic and oleophobic modification was applied, making the KFs-MXene can also be widely used in oily wastewater. Under 1 kW m−2 illumination, the evaporation rate and energy conversion efficiency of KFs-MXene with hydrophilic and oleophobic modification (O-KFs-MXene) in 1 wt% oily water can reach to 1.40 kg m−2h−1 and 82.87%, and the evaporation efficiency and rate of O-KFs-MXene remain stable in the continuous 6 h solar driven interface evaporation process.

High‐Precision and High‐Flux Separation by Rationally Designing the Nanochannels and Surface Nanostructure of Polyamide Nanofiltration Membranes

High‐precision separation with increased water permeability is critical for efficient membrane‐based water treatment processes. To achieve high selectivity toward different targeted species while allowing rapid water transportation, the structure of the membrane polyamide selective layer requires delicate regulation. Herein, an effective approach to systematically expand the pore size of polyamide layers by incorporating ammonium ion‐modified carbon dots (CDs) into the polyamide network is developed. The ammonium ions with different alkyl chain lengths attached to the CDs create nanochannels of different sizes in the network to lower the energy barrier for water transportation while maintaining high selectivity to targeted species. When the alkyl chain length of the ammonium ions reaches eight carbon atoms (i.e., C8 ions), the amphiphilic C8‐CDs induce the formation of the ridged nanostructure on the membrane surface and hence the increased membrane filtration area. The resultant thin‐film nanocomposite (TFN) membrane, denoted as the TFN‐C8‐CDs membrane, demonstrates a higher Na2SO4 rejection of 98.9% and NaCl/Na2SO4 selectivity of 83.1 than the pristine polyamide membrane, together with a tripled pure water permeability of 29.0 L m−2 h−1 bar−1. Herein, a viable approach for ingeniously designing the nanochannels and surface nanostructure of polyamide membranes for more efficient filtration processes is provided.

Hygienic problems of interaction of artificial lighting and intercellular water (literature review)

The role of water and aquaporin system in artificial lighting conditions and their importance for vision and the human body as a whole is considered. The review used the databases Scopus, Web of Science, MedLine, The Cochrane Library, EMBASE, Global Health, CyberLeninka, and RSCI. The functionally necessary level of water exchange in the human eye was shown to largely depend on the efficiency of aquaporins exposed to aggressive environment. Such effects include an excessive dose of blue light, electromagnetic radiation, and excessive concentration of mercury, copper ions, and zinc ions in the human body. In the conditions of chemical pollution, excessive blue light, the violated efficiency of aquaporins leads to swelling in the functional structures of the eye, changes in their optical characteristics. So far the conditions for the development of diseases of the visual analyzer are created. The optical system of the eye is very sensitive to the geometric dimensions of the cornea, iris, lens and Muller cells. Edema of these cells is the primary causes of optical distortions of images on the retina. The positive effect of humoral regulators of aquaporin activity (vasopressin, estrogens, component of the renin-angiotensin system) on the lens transparency was shown. Aquaporin-0 plays a key role in the development of the refractive index gradient in the mammalian eye lens to prevent spherical aberration. Aquaporin system permeates all cells of the functional structures of the body. A number of researchers suggest structural disorders of water dynamics between and within cells to be the basis of many diseases. More recent data have shown that aquaporin may also be associated with tumor, proliferation and migration of tumor cells, as well as angiogenesis in solid and hematological tumors. The discovery of aquaporins, which provide rapid transport of water through the biological membranes of all living organisms (animals, plants and microorganisms) has disproved the traditional concept and was an outstanding achievement of General biology, botany, physiology, medicine and ophthalmology. Changing the properties of intercellular water in artificial lighting (and other negative factors) is a new physiological and hygienic problem.