Multifunctional Membrane Research Articles

Three birds with one stone: Preparation of multifunctional Fe-MOF/PAN nanofiber membranes for wastewater treatment

In this research, a new NH2-MIL-88B(Fe)/polyacrylonitrile nanofiber membrane (NPNFM) was synthesized utilizing a straightforward electrospinning technique. The morphological characteristics and performance of nanofiber membranes were finely tuned via adjusting the dosage of NH2-MIL-88B(Fe) (NM88B, the “stone”). The prepared NPNFM exhibits superhydrophilicity/underwater superoleophobicity, coupled with outstanding photo-Fenton self-cleaning ability (the first two “birds”). This membrane efficiently and swiftly facilitated the separation of various surfactant-stabilized emulsions under gravitational force, achieving a separation efficiency and flux of up to 99.5 % and 350.3 L m-2h−1, respectively. The fouling on the membrane surface can be rapidly decomposed, attributing to the superior photo-Fenton activity of NM88B. Furthermore, the organic dye methylene blue (MB) was degraded by 97.4 % within 40 min under the catalytic influence of the membrane. The nanofiber membrane has good mechanical properties and its tensile strength is about 2.3 times that of the original membrane attributing to the good compatibility between NM88B and the membrane matrix (the third “bird”). This study proposed new Fe-MOF-based photo-Fenton multifunctional membranes with the characteristics of environmental stability and high efficiency in wastewater treatment fields.

Guanidinium‐Based Covalent Organic Framework Membranes for Superior Mono‐ and Divalent Cations Separation

Biological membranes exhibit extraordinary efficiency in processing ion permeability and selectivity. However, creating artificial membranes for an ideal ion separation is still challenging due to the subtle distinctions in valence and size among different ions. In the realm of biological recognition, the ultimate selectivity of ion channels is considered to stem from the specific binding interactions and appropriate charge density. Designing artificial membranes to achieve similar performance not only helps the understanding of complex ion transport in bioprocesses but also facilitates critical industrial separations. Inspiring by the remarkable performance in biological systems, a guanidinium‐based covalent organic framework membrane is designed, which exhibits an excellent capability to recognize mono‐/divalent cations, achieving K+/Mg2+ selectivity up to 202 in a mixed salt solution. Furthermore, the membrane displays rapid ion transport owing to the uniform sub‐2 nm channels. The experimental results and molecular dynamics simulations illustrate that the charge‐assisted hydrogen bonding sites and the Cl− counter ions within 1D channels play critical roles in cations sieving. Specifically, divalent ions passing through the positively charged channels need to overcome higher energy barriers than monovalent ions. These findings offer promising avenues for the development of advanced multifunctional membranes for efficient ion separation and sustainable water‐related separations.

Interfacial Engineering of Polymer Membranes with Intrinsic Microporosity for Dendrite-Free Zinc Metal Batteries.

Metallic zinc has emerged as a promising anode material for high-energy battery systems due to its high theoretical capacity (820 mAh g-1), low redox potential for two-electron reactions, cost-effectiveness and inherent safety. However, current zinc metal batteries face challenges in low coulombic efficiency and limited longevity due to uncontrollable dendrite growth, the corrosive hydrogen evolution reaction (HER) and decomposition of the aqueous ZnSO4 electrolyte. Here, we report an interfacial-engineering approach to mitigate dendrite growth and reduce corrosive reactions through the design of ultrathin selective membranes coated on the zinc anodes. The submicron-thick membranes derived from polymers of intrinsic microporosity (PIMs), featuring pores with tunable interconnectivity, facilitate regulated transport of Zn2+-ions, thereby promoting a uniform plating/stripping process. Benefiting from the protection by PIM membranes, zinc symmetric cells deliver a stable cycling performance over 1500 h at 1 mA/cm2 with a capacity of 0.5 mAh while full cells with NaMnO2 cathode operate stably at 1 A g-1 over 300 cycles without capacity decay. Our work represents a new strategy of preparing multi-functional membranes that can advance the development of safe and stable zinc metal batteries.

Hybrid Planar Copolymer Membranes with Dual Functionality against Bacteria Growth.

Antibacterial surfaces can be classified into two categories: passive surfaces, which repel bacteria by affecting surface wettability, and active surfaces, which have bactericidal properties that disrupt cell membranes upon contact. With the increasing demand for effective antibacterial solutions that combine these properties, advanced strategies are concentrating on developing surfaces with dual antimicrobial functionalities. Here, we present surfaces with nanotexture resulting from the phase separation of two different amphiphilic block copolymers displaying efficient dual functionality against bacteria growth. This approach combines the inherent antifouling properties of poly(ethylene oxide) as the hydrophilic domain of one copolymer with the antimicrobial effect of a peptide covalently attached to the hydrophilic domain of the second copolymer. The planar membranes are generated by self-assembly of the amphiphilic copolymer mixture deposited by Langmuir-Blodgett and Langmuir-Schaffer methods on a solid support, followed by covalent attachment of the antimicrobial peptides to one of the copolymers, specifically functionalized. Combining both copolymers, in terms of their properties and functionalities on the same surface, significantly limitsEscherichia colibiofilm formation and effectively eradicates bacteria during short-term incubation. While such multifunctional antimicrobial planar polymer membranes show promising potential in the design of fine coatings for small surgical or implantable devices, they are not limited to this application. Their use can be completely changed by attaching other active molecules or assemblies to induce specific multifunctionality for the targeted application.

Multifunctional Janus nanofibrous membrane with unidirectional water transport and pH-responsive color-changing for wound dressing

Chronic wounds often produce a significant volume of exudate, posing a substantial obstacle to healing. Consequently, there is a pressing demand for a versatile dressing capable of effectively managing exudate in chronic wounds. In this context, a Janus smart dressing is proposed, featuring unidirectional water transport and a pH-responsive color-changing for exudate management and wound monitoring. The dressing’s mechanisms for unidirectional water transport and color changing are elucidated. The Janus dressing consists of a polyacrylonitrile (PAN)/sodium polyacrylate (SPA)/anthocyanin (An) hydrophilic layer with antioxidant and pH-sensitive functions and a poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) hydrophobic layer, enabling unidirectional exudate drainage without reverse osmosis. Studies indicate that the Janus dressing exhibits excellent air permeability, moisture permeability, mechanical properties, cytocompatibility, and antioxidant performance while promptly responding to color variations in solutions of varying pH levels. In vivo studies demonstrated the excellent wound healing ability of Janus PHBV-PAN/SPA/An membrane. Consequently, this study provides a promising solution to develop wound dressings that can effectively manage excessive wound exudate and dressing changes.

Efficient synthesis of highly hydrophobic lignin nanoparticles and their application as nano fillers for multifunctional composite membranes

Controlling the hydrophobic behaviors of lignin nanoparticles (LNPs) is crucial and advantageous for their application as film Nano Fillers, yet it poses a significant challenge. Herein, we successfully developed a novel method for the preparation of LNPs with highly hydrophobic behaviors using ternary deep eutectic solution (DES)-H2O systems. The resulting LNPs exhibit a significantly reduced content of hydrophilic groups on their outer surface, leading to a zeta potential value of only −4.9 mV, and up to 140.0° of water contact angle (WCA). Afterwards, a “Dissolution-Restructuration” mechanism was proposed to explain the formation of the prepared LNPs. Firstly, DES demonstrates superior H-bonding capabilities, facilitating the complete disruption of inter- and intramolecular H-bonding in lignin, and resulting in the formation of a highly homogenized lignin network. Subsequently, the DES system undergoes compromise after adding water, triggering the reformation of both inter- and intramolecular H-bonding and π-π interactions. Consequently, lignin orderly self-assembles into LNPs with highly hydrophobic characteristics. Especially, using the as-prepared LNPs as Nano fillers, a series of LNPs-containing polyvinyl alcohol (PVA) films were successfully fabricated, exhibiting exceptional hydrophobic behaviors (with contact angles reaching up to 124.0°). Furthermore, the mechanical strength, UV-shielding capabilities, and biodegradability of the PVA films are significantly enhanced. This study introduces a sustainable and efficient approach for the synthesis of hydrophobic LNPs, thereby facilitating the broadening of applications for lignin-based functional composite film materials.

Bio-inspired fabrication of Ag-ZnO nanoparticle decorated Nylon 11 nanofibers: Multifunctional membrane for environmental remediation

Traditional wastewater treatment methods using nanoparticles (NPs) encounter challenges with catalyst recovery. In this study, we fabricated a Nylon 11 nanofibrous membrane (NFM) via electrospinning and functionalized it with polydopamine (PDA) to immobilize Ag-ZnO NPs for photocatalytic degradation of organic pollutants. The Nylon 11 NFM was treated with a dopamine tris buffer solution for PDA coating, which facilitated mussel-inspired attachment of the ZnO NPs. These NPs served as a nucleation site for the biomimetic nucleation of Ag-ZnO NPs during the hydrothermal process. The synthesized composite membrane was characterized by various microscopic and spectroscopic techniques. The water contact angle decreased from 135° (Nylon 11 NFM) to 41° (PDA/Nylon 11 NFM) and the filtration efficiency improved 10 folds (from 15.92 Lm-2h−1 to 170.60 Lm−2 h−1) at ambient conditions. The Ag-ZnO/PDA/Nylon 11 NFM showed strong antimicrobial activity against different bacterial strains and excellent photocatalytic degradation for methyl orange with a rate constant of 0.0431 min−1, significantly surpassing other configurations. The membrane exhibited excellent stability, reusability and consistent photocatalytic efficiency over multiple cycles. It is easily recoverable from the reaction mixture, and suitable for repeated use, making it a promising candidate for environmental remediation due to its antibacterial properties, photocatalytic activity, enhanced filtration efficiency, and reusability.

A novel multifunctional photocatalytic membrane based on β-FeOOH for oily wastewater purification

In order to deal with the environmental pollution caused by complex oily wastewater, it is necessary to develop filtration membrane materials. However, significant challenges such as poor effect of emulsion separation, limited functionality, and susceptibility to membrane fouling require urgent resolution. Here, we successfully prepared a β-hydroxyl iron oxide/polydopamine-polyethylenimine/polyacrylonitrile (β-FeOOH/PDA-PEI/PAN) nanofiber membrane for treatment of complex wastewater by growing PDA-PEI on a blow-spinning PAN nanofiber membrane and decorating the membrane with β-FeOOH. The porous structure and the large number of hydrophilic groups greatly increase the hydrophilicity of the membrane and give the membrane high permeation fluxes (11531.26 L m−2 h−1) for surfactant-free kerosene-in-water emulsion. The loaded β-FeOOH nanorods increase the roughness of the membrane surface, which enhances the underwater superoleophobic ability of the membrane, and promotes the demulsification of the emulsion and makes it have high separation efficiency of 99.48 % for surfactant-stabilized kerosene-in-water emulsion. In addition, the β-FeOOH/PDA-PEI/PAN also exhibited high organic dye removal efficiency (99.38 %) due to the presence of β-FeOOH. The synergistic effect of low oil adhesion and photocatalysis enhances the antifouling and self-cleaning performances of the material. Significantly, the multifunctional membrane also shows exceptional oil/water separation ability and good stability. The presented synergistic strategy of β-FeOOH/PDA-PEI/PAN membrane materials represents a prospective candidate for the treatment of complex wastewater.

Optimization of Reactive Ink Formulation for Controlled Additive Manufacturing of Copolymer Membrane Functionalization.

Multifunctional, nanostructured membranes hold immense promise for overcoming permeability-selectivity trade-offs and enhancing membrane durability in challenging molecule separations. Following the fabrication of copolymer membranes, additive manufacturing technologies can introduce reactive inks onto substrates to modify pore wall chemistries. However, large-scale implementation is hindered by a lack of systematic optimization. This study addresses this challenge by elucidating the membrane functionalization mechanisms and optimal manufacturing conditions using a copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) "click" reaction. Leveraging a data science toolkit (e.g., nonlinear regression, uncertainty quantification, identifiability analyses, model selection, and design of experiments), we developed two mathematical models: (1) algebraic equations to predict equilibrium concentrations after preparing reactive inks by mixing copper sulfate, ascorbic acid (AA), and an alkynyl-terminated reactant; and (2) reaction-diffusion partial differential equations (PDEs) to describe the functionalization process. The ink preparation chemistry with side reactions was validated through pH and UV-vis measurements, while the diffusion and kinetic parameters in the PDE model were calibrated using time-series conversion of the azide moieties inferred from Fourier-transform infrared spectroscopy. This modeling framework avoids redundant experimental efforts and offers a functionalization protocol for scaling up designs. Ink optimization problems were proposed to reduce the use of expensive and environmentally insulting ink materials, i.e., Cu(II), while ensuring the desired chemical distributions. With optimal ink formulation Cu(II)/AA/alkyne = 1:1:2 identified, we uncovered trade-offs between Cu(II) usage and functionalization time; for example, in continuous roll-to-roll manufacturing with a conserved functionalization bath setup, our optimal operational conditions to achieve ≥90% functionalization enable at least a 20% reduction in total copper investment compared to previous experimental results. The data science-enabled ink optimization framework is extendable for on-demand multifunctional membranes in numerous future applications such as metal recovery from wastewater and brine.

Bifunctional TiO2-Coated SSM for Efficient Emulsion Separation and Photocatalytic Degradation of Soluble Organic Pollutants.

The oily wastewater containing complex organic pollutants poses a great threat to the environment and human beings. At present, the membrane used to treat oily wastewater has some problems, such as complicated preparation and serious membrane pollution. Superhydrophilic/underwater superoleophobic membranes overcome the problems of the surface of the membrane being easily polluted or even blocked by oil, so they have been widely studied by many researchers. In this work, we used an electrochemical deposition method to uniformly load titanium dioxide (TiO2) nanoparticles onto pretreated stainless-steel mesh for efficient oil-in-water (O/W) emulsion separation (TiO2@SSM). The membrane of TiO2@SSM exhibited superior superhydrophilicity and underwater superoleophobicity, ensuring high O/W separation efficiency, reaching 99.8%, and fast water flux of up to 208.0 L·m-2·h-1 for various O/W emulsions. Meanwhile, the membrane possessed a desirable photocatalytic degradation property under visible light irradiation and a degradation efficiency of 98.1% for RhB pollutant. Specially, the as-prepared membrane had long-lasting robustness, sustainability, and recyclability through the cyclic experiments of emulsion separation and photocatalytic degradation. Our results provide a simple and universally applicable route to construct a multifunctional membrane for simultaneously achieving water purification in complex oily wastewater.

Flower-like ZnO/BiOI p–n heterojunction composite membrane composed of nanosheets for enhanced photodegradation of water-soluble pollutant and high efficiency oil–water emulsion separation

The emulsified oil wastewater produced from the petrochemical industries and people’s daily life would cause severe harm to the ecological environment if improperly treated. Thus, the development of membranes with efficient oil–water separation and self-cleaning property remains a key global research direction. In this study, p-n heterojunctions membrane with BiOI@ZnO hierarchical flower-like-nanosheets structures (BiOI@ZnO@SSM) has been successfully fabricated through two-step electrodeposition method. The BiOI@ZnO@SSM is capable of separating water and oil from emulsified oil wastewater and performing efficient adsorption and photocatalytic degradation of organic pollutants in water. The separation efficiency of BiOI@ZnO@SSM for numerous oil-in-water (O/W) emulsions exceeded 99.3 % as well as a fast permission flux up to 299.8 L·m−2·h−1. And the degradation efficiency of BiOI@ZnO@SSM for Rhodamine B (RhB) can reach to 99.0 % in 80 min under visible-light irradiation, which is 1.5 times as high as that of ZnO@SSM. The obviously enhanced photocatalytic activity of BiOI@ZnO@SSM is due to the formation of p-n heterojunction between p-type BiOI and n-type ZnO, which broadens the light absorption range, promotes the effective separation and prolongs the lifetime of electron and hole pair and realizes efficient degradation of organic pollutants. Meanwhile, multidimensional and hierarchical nanoflowers structure is not only helpful to improve the utilization of light, but also can increase more catalytic active sites. After ten cycles, this membrane maintained high emulsion separation efficiency of 99.6 % and the photodegradation efficiency remained above 94.5 %, demonstrating its good recyclability and stability. This durable and multifunctional heterojunction composite membrane with a flower-like structure is of great application potential in dealing with practically emulsified wastewater.

Enhanced synergistic catalysis of bisphenol A in river water using an anti-aging photocatalytic membrane

Bisphenol A (BPA), as an endocrine disruptor, poses a potential threat to ecosystems and human health in aquatic environments. Membrane catalytic systems can accelerate the degradation of BPA and facilitate its conversion into harmless compounds. Nevertheless, the complex nature of the water environments and the limited stability of catalysts often result in challenges such as catalyst aging and deactivation. Herein, an anti-aging multifunctional AgFeO2 catalytic material with electron transfer membrane support was prepared for synergistic catalysis of low-energy LED light (12 W) excitation and peroxydisulfate (PDS) activation. The anti-aging photocatalytic membrane completely degraded 10 ppm of BPA within 30 min, and did not show significant aging after the long-term synergistic catalytic process. In addition, actual river water was employed to assess the aging process and catalytic efficiency in a practical environment. A 60.79 cm2 photocatalytic membrane completely purified 10 L of BPA polluted river water, while the total organic carbon content decreased by 50 %. This was mainly due to the synergistic catalytic effect of the membrane, which boosted photoelectron transfer through electron transfer shortcuts, thereby enhancing persulfate activation. Overall, the multifunctional membrane provides an effective strategy for achieving a long-lasting catalytic effect and controlling photocatalyst aging in practice.

Fabrication and characterization of low-cost ceramic membranes from coal fly ash and natural sand

Coal fly ash, an industrial solid waste product, and natural sand, a commonly available and inexpensive natural material, were used to fabricate ceramic membranes that are both affordable and sustainable. These ceramic membranes were fabricated by the uniaxial compaction technique using a manual hydraulic pressing machine. The effects of various fabrication parameters such as the sintering temperature and the amount of natural sand utilized, on the properties of the resulting ceramic membranes were extensively evaluated. X-ray fluorescence (XRF) analysis of the starting materials confirmed the presence of SiO2 and Al2O3, two key inorganic materials required for the fabrication of ceramic membranes. Heavy metals present in the raw coal fly ash were leached out prior to the fabrication process. The coal fly ash and natural sand were mixed in different proportions and the fabricated ceramic membranes were characterized using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM), X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDS), and Thermogravimetric analysis (TGA). The properties of the optimized membranes were further studied to ascertain their mechanical strength, chemical stability, porosity, water absorption, water permeability, and shrinkage behaviour. The membrane fabricated with 20 wt% sand content and at 1000 °C sintering temperature had pore size of 0.64 µm and 34.7 % porosity, exhibited good mechanical strength (7.71 MPa), and exceptional chemical stability. The membrane also showed a remarkable water permeability of 32.23 L/m2/h. This study showed that natural sand and coal fly ash can be efficiently employed to develop a multifunctional filtration membrane with adjustable properties that can be utilized in water purification.

Enhanced X-ray shielding efficiency and visible light degradation performance of a multilayer composite protective material

To mitigate the adverse effects of high-energy radiation, such as X-rays, on patients during medical procedures, a multifunctional composite nanofibrous membrane has been engineered to shield against low-energy X-rays. This study involves integrating processed oil-tea camellia shells (OCS) powder into molten polylactic acid (PLA) for modification. Concurrently, metallic Bi is introduced to enhance Bi2WO6, which is subsequently combined with modified PLA and electrospun into nanofibrous membranes for photocatalytic antimicrobial and organic pollutant degradation. Additionally, sodium hyaluronate (NaHA) and a silver nanoparticle solution are electrospun with PLA to form a skin-friendly protective layer. Following this, a chitosan (CS) solution containing WO3 and B4C is used as a coating on the multilayered membranes. The membranes are then freeze-dried to create sandwich-structured multilayer composite protective material. This method addresses challenges associated with polylactic acid (PLA) in electrospinning and alleviates limitations such as low light absorption and slow charge transfer in Bi2WO6. Compared to similar materials, this composite material is lightweight, flexible for cutting, and exhibits strong X-ray shielding capabilities. The composite nanofibrous membrane demonstrates a shielding efficiency of 97.75 ± 2.05 % at low X-ray energy (46 kVp). Moreover, under visible light, the membrane generates reactive oxygen species, resulting in the efficient removal of 98.03 % of methylene blue (MB), 96.35 % of rhodamine B (Rh.B), and 91.51 % of methyl orange (MO) within 180 minutes. Furthermore, it displays bactericidal activity against E. coli and S. aureus under both dark and light conditions. In natural settings, the composite membrane undergoes gradual degradation in soil, completely decomposing within 28 days due to the influence of rainfall and microorganisms. Consequently, this composite membrane holds significant promise for specialized medical protective applications.

Fabrication of flexible multifunctional graphene-based composite membrane with improved hydrophobicity and thermal conductivity characters for thermal management

The lifetime of electronic devices in complex environments is affected by the impact of high temperature water vapor on their performance. Equipping electronic devices with superhydrophobic properties and improved thermal conductivity will be the strategy of the future. In this paper, a surface material with high thermal conductivity and superhydrophobic properties is explored to address the problem of electronic device failure caused by heat and water vapor. To solve this problem, anti-temperature superhydrophobicity can be obtained by spraying alumina/nano-silicon carbide/thermoplastic elastomer composite powder (Al2O3/nano-SiC/SEBS) modified with 1 H,1 H,2 H,2H-perfluorooctyltriethoxysilane (POTS) on graphene membranes. A spherical Al2O3/nano-SiC composite superhydrophobic coating (ASS-GM) was formed on the surface of graphene-based composite membranes by spraying method. The results showed that the optimal ratio was m(Al2O3): m(SiC) = 8:1, and the static water contact angle of the coating was 162 ± 2.5°, and the surface energy was reduced. The ASS-GM significantly improves the thermal conductivity and superhydrophobicity of graphene-based composite membranes, achieving a double improvement in performance. The coating also offers excellent self-cleaning and antifouling properties compared to other materials. The ASS-GM is able to maintain a certain hydrophobicity angle (156 ± 1.5°) in harsh environments. This work provides practical applications for electronic coatings, which are important for improving the overall reliability and durability of electronic products.

Multifunctional Wearable Conductive Nanofiber Membrane with Antibacterial and Breathable Ability for Superior Sensing, Electromagnetic Interference Shielding, and Thermal Management

Multifunctional Wearable Conductive Nanofiber Membrane with Antibacterial and Breathable Ability for Superior Sensing, Electromagnetic Interference Shielding, and Thermal Management

Biocompatible chitin-based Janus hydrogel membranes for periodontal repair

Periodontal defects caused by severe periodontitis are a widespread issue globally. Guided tissue regeneration (GTR) using barrier membranes for alveolar bone repair is a common clinical treatment. However, most commercially available collagen barrier membranes are expensive and lack the antibacterial properties essential for effective bone regeneration. Herein, we report a natural polysaccharide chitin hydrogel barrier membrane with a Janus structure (ChT-PDA-p-HAP), featuring high antibacterial and protein-repelling activity on the outer side and good osteogenesis ability on the inner side. This multifunctional membrane is fabricated though a three-step process: (i) dissolution and regeneration of chitin, (ii) co-deposition with polydopamine (PDA) and poly(sulfobetaine methacrylate) (pSBMA), and (iii) coating with gelatin-hydroxyapatite (gelatin-HAP). In vitro cell experiments demonstrated the membrane's high biocompatibility and significant osteogenic activity. In vivo implantation in rats with periodontal defects revealed that the cemento-enamel junction index of the ChT-PDA-p-HAP membrane (1.165 mm) was superior to that of the commercial Bio-Gide® membrane (1.350 mm). This work presents a method for fabricating a chitin-based Janus barrier membrane, potentially expanding the use of chitin in tissue engineering. Statement of significanceThis study introduces a Janus hydrogel membrane based on chitin, tailored for guided tissue regeneration in periodontal defects. By combining antibacterial properties and osteogenic capabilities in a single membrane, the ChT-PDA-p-HAP membrane represents a significant advancement over traditional collagen barriers. Its outer surface, enhanced by Cu2+ and PDA-pSBMA coatings, resists bacterial colonization and protein adhesion effectively, while the inner side, coated with gelatin-HAP, promotes robust bone formation. In vitro experiments demonstrate high biocompatibility and substantial osteogenic differentiation, while in vivo testing in rat models confirms good therapeutic efficacy compared to commercial membranes. This multifunctional approach not only utilizes chitin's abundant natural resource but also integrates simple coating techniques to enhance therapeutic outcomes in periodontal tissue engineering, offering promising avenues for broader biomedical applications.

Application and Development of Hydrogel in Soilless Culture

AbstractSoilless culture refers to the method of cultivating plants without soil as a growing medium, and the use of hydrogel in soilless culture overcomes many technical difficulties, but there are many applications that just stay at the experimental level, with fewer applications in fields. Although many new functionalized hydrogels may help to overcome the shortcomings of traditional media and give them more functionality, little research on hydrogels over the past decades has been reflected in soilless culture techniques. This paper details the concept and development of soilless culture, as well as several applications of hydrogels in soilless culture, including the use of hydrogels as soilless culture substrates and the application of hydrogel membranes. The important roles of different types of hydrogels in soilless culture, such as antimicrobial properties, salt tolerance and high water absorption, are highlighted, and these excellent properties largely overcome a series of drawbacks of traditional cultivation methods. The application of hydrogels in pest control is also discussed. Hydrogel applications to soilless culture have better prospects for the creation of more promising multifunctional composite hydrogel membranes and hydrogel substrates capable of supporting plants throughout their growth cycle.

All-electrochemical-prepared, efficient and robust superhydrophilic/underwater superoleophobic meshes for synchronously achieving oil-water separation and water-soluble pollutant photodegradation

Superhydrophilic/underwater superoleophobic “water-removing” type membranes can overcome the issue of surface themselves easily fouled or even blocked by oils that seriously affects the oil-water separation capacity and limits the recycle use, and thus attract a great deal of research attention. In this work, we employed the electrochemical deposition method to fabricate Cu3(PO4)2 nanosheets (NSs) vertically grown on a copper mesh (COM) to achieve efficient oil-water separation, followed by the deposition of titanium dioxide (TiO2) nanoparticles and graphitic carbon nitride (g-C3N4) nanosheets on the surface of Cu3(PO4)2 nanosheets-wrapped mesh (Cu3(PO4)2@COM), respectively. The composited meshes of TiO2@Cu3(PO4)2@COM and g-C3N4@Cu3(PO4)2@COM not only showed the considerable superhydrophilic/underwater superoleophobic property in the application of oil-water separation, but also simultaneously exhibited the desirable photocatalytic activity for the degradation of water-soluble pollutants as the water passed through the meshes. The oil-water separation efficiency of TiO2@Cu3(PO4)2@COM and g-C3N4@Cu3(PO4)2@COM can reach as high as 97 % and 96 % that both of meshes have the water flux of various water-oil mixtures above 3250 L/m2h, along with their degradation efficiency of 79 % and 90 % for RhB pollutant under full spectrum light irradiation, respectively. In addition, the as-prepared meshes have the robust, sustainable and stable properties through ten-cycles test of oil-water separation and photocatalytic degradation without significant performance decay. Our primary results provide a potential and simple route to construct multifunctional membrane materials for synchronously achieving water purification in oily wastewater.

Mechanobiological mechanisms in the remediation of soil lead pollution using two-dimensional carbon materials and Morchella: A molecular-level study

Graphene-based 2D carbon composites and Morchella mushrooms are used in the paper to study the mechanobiological mechanisms of soil lead remediation. Soil is contaminated with lead, which threatens ecosystems and human health, making it even more important to find remedies. To fully comprehend these processes, present-day materials, and organic compounds are needed to improve soil nutrition and eradicate lead. To deal with the challenge of finding effective means of lead removal; limitations associated with traditional soil pollution remediation methods; and merging biology and material sciences. Multifunctional graphene wettability-patterned nanocoated membranes (MGW-PNM) is a novel technique developed to overcome these challenges. Such processes result in membranes with different wettability patterns that take advantage of the properties of graphene. This facilitates better interaction between the membrane itself and the surrounding soil as well as lead contaminants by modifying its hydrophobicity or hydrophilicity characteristics. For effective removal of lead, extensive simulation studies were done using MGW-PNM. In line with this, it can be inferred that MGW-PNM also remediates highly capable soils at high-efficiency levels. This was established when comparing modern techniques to past ones where considerable improvements were made on how much lead is extracted from them. The study suggests new ways of addressing environmental contamination resulting from microbial activities in soils by combining advanced materials with biological substances such as Morchella spp. For this purpose, it investigates various molecular interactions occurring among carbonaceous species called Morchella microbes and environmental pollutants like those including Pb.