Excellent Antifouling Properties Research Articles

Polyoxometalates decoration combining with solvent activation for enhanced separation performance of nanofiltration membrane

Nanofiltraion (NF) membranes are promising candidates for overcoming critical global issues of access to clean water. However, current NF membranes are hampered by the trade-off between the water permeability and selectivity as well as the fouling propensity. In this work, a facile surface decoration simultaneously combined with solvent activation strategy was adopted for the NF membrane modification via simply immersing membrane into the polyoxometalates (POMs) ethanol solution. The introduction of POMs by coordination assembly increases the membrane hydrophilic and electronegativity, and the ethanol loosens the membrane selective layer, leading to the enhanced membrane perm-selectivity and anti-organic fouling property. The permeance and Na2SO4 rejection of the optimized modified NF membrane are 14.90 ± 0.21 LMH/bar and 99.20 ± 0.38 %, which are ∼20 % and more than 3 % increments compared with those of the control membrane, respectively. The modified NF also reveals a lower permeance decline as well as a higher flux recovery toward both positive and negative charged foulants. In addition, benefiting from the biocidal activity of the POMs, the membrane anti-biofouling property is also significantly improved under an extremely low loading of POMs. More importantly, the chemical stability of the modified NF membrane is reinforced due to the protection from the introduced POMs. Our work contributes to revitalizing the prospect of developing NF membranes with excellent filtration performance and antifouling property.

Surface Reconstruction of Silicone-Based Amphiphilic Polymers for Mitigating Marine Biofouling.

Poly(dimethylsiloxane) (PDMS) coatings are considered to be environmentally friendly antifouling coatings. However, the presence of hydrophobic surfaces can enhance the adhesion rate of proteins, bacteria and microalgae, posing a challenge for biofouling removal. In this study, hydrophilic polymer chains were synthesised from methyl methacrylate (MMA), Poly(ethylene glycol) methyl ether methacrylate (PEG-MA) and 3-(trimethoxysilyl) propyl methacrylate (TPMA). The crosslinking reaction between TPMA and PDMS results in the formation of a silicone-based amphiphilic co-network with surface reconstruction properties. The hydrophilic and hydrophobic domains are covalently bonded by condensation reactions, while the hydrophilic polymers migrate under water to induce surface reconstruction and form hydrogen bonds with water molecules to form a dense hydrated layer. This design effectively mitigates the adhesion of proteins, bacteria, algae and other marine organisms to the coating. The antifouling performance of the coatings was evaluated by assessing their adhesion rates to proteins (BSA-FITC), bacteria (B. subtilis and P. ruthenica) and algae (P. tricornutum). The results show that the amphiphilic co-network coating (e.g., P-AM-15) exhibits excellent antifouling properties against protein, bacterial and microalgal fouling. Furthermore, an overall assessment of its antifouling performance and stability was conducted in the East China Sea from 16 May to 12 September 2023, which showed that this silicon-based amphiphilic co-network coating remained intact with almost no marine organisms adhering to it. This study provides a novel approach for the development of high-performance silicone-based antifouling coatings.

Prussian Blue Encapsulated with Brush-like Polyorganosiloxane Nanospheres with Tunable Functionality

Faced with higher demands of pigments in various applications, the performance of pigments in a specific system is in urgent need of optimization and improvement. Polyorganosiloxane (POS) stands out among various encapsulating polymeric materials for pigment modification due to its superior thermal stability and alkali resistance. However, the inherent hydrophobicity of POS causes poor stability in aqueous systems, which is usually applied in environmentally friendly applications. Grafting hydrophilic polymer chains on the surface of POS could improve water dispersity. In addition, the encapsulated pigment can also be endowed with various functionalities by selecting or combining grafted polymers. Herein, we reported a strategy to encapsulate Prussian blue (PB27) with POS grafted with poly(acrylic acid) (PAA) or poly(N-(2-hydroxyethyl) acrylamide) (PHEAA) to allow better stability and functionality of the composite pigment particles, denoted as PB27@POS@PAA or PB27@POS@PHEAA, respectively. The effect of the number of monomers and the amount of initiator potassium persulfate (KPS) on the brush thickness of the grafted polymers was studied, along with various performance properties and the functionality of PB27@POS@PAA and PB27@POS@PHEAA. The dispersity, alkali resistance, and high-temperature stability are studied. The brush-like composite pigment performs better after centrifugation (5000 rpm, 30 min) or treatment under 90 °C when the dosage of grafting monomer AA or HEAA reaches 400 wt%. Optimal alkali resistance was obtained for PB27@POS@PAA (AA, 200 wt%) with a particle size variation of only 31 nm after 8 h. Comparably, PB27@POS@PHEAA behaved worse under similar conditions. Moreover, PB27@POS grafted with PAA was responsive to pH and that with PHEAA showed excellent antifouling properties, which could also be replaced by other functional monomers if needed.

Fabrication of novel polyethersulfone (PES) photocatalytic membranes with excellent permeability and antifouling properties using TiO2–AgBr–Ag–SBA-15 nanofillers for cefixime removal

Fabrication of novel polyethersulfone (PES) photocatalytic membranes with excellent permeability and antifouling properties using TiO2–AgBr–Ag–SBA-15 nanofillers for cefixime removal

Photothermal Superhydrophobic Surfaces with Dual Self-healing Capabilities

In this study, superhydrophobic coatings with dual self-healing functions were constructed by spraying fluorosilane-modified SiO2 aerogel powders and multi-walled carbon nanotubes on composite films composed of polycaprolactone and epoxy resin. The synergy between the thermally healable polycaprolactone/epoxy resin layer and the photothermal effect of the multi-walled carbon nanotubes allows the coating to repair scratches on the coated surface under light. The porous surface, composed of fluorinated SiO2 aerogel powders and multi-walled carbon nanotubes, provides surface roughness while acting as a storage site for low surface energy healing agents, creating the conditions for surface chemical energy repair. After oxygen plasma etching, the samples were exposed to a solar intensity for 30 min to restore the superhydrophilic state to the superhydrophobic state. The scratches on the sample surface of about 80 μm can be repaired after 20 min of light exposure. The dual healing of chemical energy and the rough structure of the material surface is expected to solve the problem that superhydrophobic surfaces are prone to damage and fail in practical applications. In addition, the material has excellent antifouling and self-cleaning properties. In synergy with the self-healing properties, the material is expected to be recyclable in the long term.

Photoactivatable poly(2-oxazoline)s enable antifouling hydrogel membrane coatings

In recent years, hydrophilic poly(2-oxazoline)s have been examined as an alternative polymer to poly(ethylene glycol) (PEG) with added stability and chemical versatility. They show excellent anti-fouling properties and, like PEG, are of interest in many fields where bio-inertness or anti-adhesiveness are important such as for medical devices, tissue engineering, biosensors, or drug delivery carriers. Surprisingly few studies have utilized this polymer class for the preparation of anti-fouling membranes. Here we describe a new termination reaction of the living cationic ring-opening polymerization of 2-oxazolines in which a benzophenone group is introduced as a photoactivatable terminal head group of poly(2-oxazoline)s. Using 4-vinylbenzyl chloride as initiator, heterotelechelic poly(2-methyl-2-oxazoline) (PMOXA) macromonomers were synthesized and copolymerized with hydroxyl-functional PMOXA macromonomers to yield photoactivatable PMOXA-based prepolymer bottle brushes. Likewise, star-PMOXAs were synthesized by using a trifunctional initiator. Photoactivatable PMOXA prepolymers allowed us to readily form anti-fouling hydrogels by a simple and versatile CH-insertion cross-linking (CHic) process. Hydrogels were applied to poly(ether sulfone) ultrafiltration membranes as pore coating and the pure water permeance (PWP) was investigated as a function of hydrogel architecture and cross-link density. Anti-fouling hydrogel pore-coated membranes having PWPs on the order of hundred kg·m−2·h−1·bar−1 were obtained.

Scalable fabrication of multifunctional polylactic acid fibrous membranes with enhanced superhydrophobicity and radiative cooling performance

The disadvantages of traditional bio-based materials melt centrifugal spinning, such as low efficiency, long cycle and poor performance, limit its industrialization process. Herein, a scalable strategy was proposed for the fast and scale fabrication of bio-based melt centrifugal spinning fiber. The polymer melt was continuously transported to the high-speed rotating centrifugal disk, where it was rapidly conveyed and separated. The separated melt was then drawn and cooled by the synergistic supergravity and high-pressure cyclone field, resulting in formatting a nonwoven fabric by self-bonding alone with a diameter of ∼3 μm. Compared to conventional white CVC fabrics, the fabricated polylactic acid fibrous membranes demonstrated exceptional biocompatibility (cell viability of 98.7%), radiative cooling properties and favorable emissivity (94.1%), which can reduce the covered object temperature by 4.6 °C during hot summer. Furthermore, the water vapor transmission rate, moisture regain, water absorption, and boiling water shrinkage rate of PP20/8-F are 39.98 g m−2 h−1, 2.31%, 2.09%, and 8.11%, respectively, meeting the comfort requirements of wearable fabrics. The robust superhydrophobicity with a water contact angle of 153 ± 1° provides excellent antifouling and self-cleaning properties. This novel bio-based material melt centrifugal spinning method provides a viable strategy for the industrial preparation of high-performance and functionalized fibrous.

Rational design and application of superhydrophobic fluorine-free coating based on double-decker silsesquioxane for oil-water separation

A superhydrophobic coating of methoxysilane-functionalized double-decker silsesquioxane (M-DDSQ) on cotton fabric was synthesized using the dip-coating method. Characterizations using FT-IR, XPS, SEM, and AFM demonstrated that M-DDSQ-fabric has chemically covalently grafted M-DDSQ on the fabric surface and exhibits excellent chemical stability and antifouling properties compared to the pristine fabric. Interestingly, the novel fluorine-free fabric has a superhydrophobicity property with a water contact angle (WCA) of 150°, which efficiently and quickly separates oil from water. The maximum flux reaches 88,420 L m−2 h−1, and the separation efficiency is greater than 99 %. Furthermore, its outstanding superhydrophobic durability against tape-peeling, abrasion, and chemicals such as strong acidic and alkaline solutions is attributed to the strong chemical bonding between M-DDSQ and the fabric surface. This simple and efficient method enables the preparation of a durable superhydrophobic fluorine-free coating, which can be applied to synthesize other superhydrophobic materials for self-cleaning, especially for oil-water separation applications.

Antifouling and antimicrobial 3D printed small household appliances with incorporation of zwitterions and quaternary ammonium compounds

Nowadays, small household appliances had revolutionized the way we live and work with unparalleled innovation and performance, but the bacterial colonization of the appliance surfaces was a widespread phenomenon with consequences on human health and well-being. In this work, a spectrum of composite resins with addition of different ratios of sulfobetaine methacrylate (SBMA) and 12-methacryloyloxydodecylpyridinium bromide (MDPB) were prepared by photocuring 3D printing technology for improving their antifouling and antimicrobial properties. A remarkable improvement in mechanical property was observed as a result of the electrostatic attraction between SBMA, MDPB and polyurethane. The composite resins exhibited a relatively hydrophilic surface because of the high hydration capacity of zwitterionic SBMA, which enabled effective suppression of protein adsorption and bacterial adhesion, resulting in excellent antifouling property. Meanwhile, the antimicrobial property of the composite resins against both S. aureus (Gram-positive bacteria) and E. coli (Gram-negative bacteria) was significantly improved in the presence of MDPB, and the resins with 20% MDPB showed the best antimicrobial property, with a reduction rate of 98.3% and 97.1% against S. aureus and E. coli, respectively. Not only that, all composite resins persevered low cytotoxicity and good biocompatibility. More importantly, a series of children's nebulizers with enhanced protein adsorption resistance, reduced bacterial fouling and sustained biocompatibility were fabricated by photocuring 3D printing technology using the composite resins, confirming the success of antifouling and antimicrobial composite resin strategy in small household appliances.

PEG-functionalized aliphatic polycarbonate brushes with self-polishing dynamic antifouling properties

Hydrophilic antifouling polymers provide excellent antifouling effects under usual short-term use conditions, but the long-term accumulation of contaminants causes them to lose their antifouling properties. To overcome this drawback, surface-initiated ring-opening graft polymerization (SI-ROP) was performed on the surface of the material by applying the cyclic carbide monomer 4′-(fluorosulfonyl)benzyl-5-methyl-2-oxo-1,3-dioxane-5-carboxylate (FMC), which contains a sulfonylfluoride group on the side chain, followed by a “sulfur(IV)-fluorine exchange” (SuFEx) post click modification reaction to link the hydrophilic polyethylene glycol (PEG) to the polyFMC (PFMC) brush, and a novel antifouling strategy for self-polishing dynamic antifouling surfaces was developed. The experimental results showed that the antifouling surface could effectively prevent the adsorption of proteins such as bovine serum albumin (BSA, ∼96.4%), fibrinogen (Fg, ∼87.8%) and lysozyme (Lyz ∼69.4%) as well as the adhesion of microorganisms such as the bacteria Staphylococcus aureus (S. aureus) (∼87.5%) and HeLa cells (∼67.2%). Moreover, the enzymatically self-polished surface still has excellent antifouling properties. Therefore, this modification method has potential applications in the field of biosensors and novel antifouling materials.

Scalable, flexible, ultra-strong, free-standing papery all carbon nanotube membrane with excellent separation and antifouling properties

Carbon nanotube (CNT) based membranes have shown tremendous promise for water purification. However, fabricating free-standing all CNT membranes with excellent separation and antifouling properties remains challenging. Here, a densified flexible, ultra-strong, free-standing papery all CNT membrane with excellent separation and antifouling properties is reported. The chemically densified free-standing CNT membrane has an extremely high tensile strength up to 330 MPa, four times higher than the original CNT membrane and one order of magnitude higher than most polymeric membranes. The negatively charged surface of the densified CNT membrane enables efficient separation of two dyes even with similar molecular sizes. Meanwhile, the densified CNT membrane exhibits superior antifouling performance during the filtration of dyes, humic acid and bovine serum albumin solutions, and oil-in-water emulsions due to its reinforced hydration layer induced by the hydrophilic functional groups resulting from chemical densification. The chemically densified CNT membrane shows not only excellent separation and antifouling performance, but also superior long-term stability and regeneration performance in the filtration of foulant-containing solutions. This study may pave the way for large-scale application of densified free-standing all CNT membranes in the realm of water treatment.

Improved Protein Removal Performance of PES Hollow-Fiber Ultrafiltration Membrane with Sponge-like Structure.

The research used polyethersulfone (PES) as a membrane material, polyvinylpyrrolidone (PVP) k30 and polyethylene glycol 400 (PEG 400) as water-soluble additives, and dimethylacetamide (DMAc) as a solvent to prepare hollow-fiber ultrafiltration membranes through a nonsolvent-induced phase separation (NIPS) process. The hydrophilic nature of PVP-k30 and PEG caused them to accumulate on the membrane surface during phase separation. The morphology, chemical composition, surface charge, and pore size of the PES membranes were evaluated by SEM, FTIR, zeta potential, and dextran filtration experiments. The paper also investigated how different spinning solution compositions affected membrane morphology and performance. The separation efficiency of membranes with four different morphologies was tested in single-protein and double-protein mixed solutions. The protein separation effectiveness of the membrane was studied through molecular weight cutoff, zeta potential, and static protein adsorption tests. In addition, the operating pressure and pH value were adjusted to improve ultrafiltration process conditions. The PES membrane with an intact sponge-like structure showed the highest separation factor of 11, making it a prime candidate membrane for the separation of bovine serum albumin (BSA) and lysozyme (LYS). The membrane had a minimal static protein adsorption capacity of 48 mg/cm2 and had excellent anti-fouling properties. When pH = 4, the BSA retention rate was 93% and the LYS retention rate was 23%. Furthermore, it exhibited excellent stability over a pH range of 1-13, confirming its suitability for protein separation applications.

Antifouling macrocyclic-engineered PVDF membrane for the low-pressure separation of surfactant-stabilized oily wastewater

Fouling is a common phenomenon which affects the long-term efficacy of membranes in the practical treatment of oily wastewater. It often results in a dramatic decline in flux, and a consequent increase in maintenance and operational cost. To address this, various substrates have been incorporated during membrane fabrication to enhance the fouling resistance, and improve the separation efficiency. Herein, we report the fabrication of a novel symmetrical ball-copper phthalocyanine incorporated PVDF membrane (CuPc@PVDF) for the effective separation of surfactant-stabilized oil-in-water emulsions. The symmetrical ball-Cu phthalocyanine with four non-peripheral substituents synthesized ab-initio and characterized using UV–vis, FT-IR, 1H NMR, and MALDI-TOF spectroscopies was added to the casting solution during membrane fabrication resulting in the formation of highly hydrophilic and anti-fouling CuPc@PVDF membrane. In contrast to the PVDF membrane, having a water contact angle of 82.3° ± 0.7°, the CuPc@PVDF membrane demonstrated high hydrophilicity with a contact angle of 55.5° ± 0.5°, and pure water permeance up to 768 LMH at 3 bar. It further achieved 99.9 % rejection of oil with size in the range of 50–450 nm at 1 bar, and demonstrated high stability and excellent anti-fouling property during 10 cycles of continuous demulsification, with a flux recovery ratio (FRR) of 98.5 %, and extremely low irreversible flux of 1.5 %. Similarly, the CuPc@PVDF membrane exhibited high resistance to accelerated organic fouling, maintaining a steady flux and an FRR of 93.0 % during 1 hour of continuous operation with 10 ppm sodium alginate and Ca2+ ions. This study reports a novel strategy to enhance the fouling resistance of demulsification membranes, and could be further explored in the design of next generation of advanced membranes for the purification of oily wastewater.

Highly efficient antifouling and toughening hydrogel for ship coatings

Hydrogels possess characteristics of anti-protein adsorption, which have attracted significant attention in the field of ship antifouling. Traditional hydrogels often exhibit poor mechanical properties and lack long-term application value. Herein, a PEGp hydrogel for underwater antifouling applications was prepared. PEGp hydrogel demonstrates excellent water retention, elasticity, and antifouling properties. It can effectively resist the adsorption of proteins and bacteria. The long-term antifouling test shows that PEGp hydrogel has application prospects in the marine environment. Additionally, molecular dynamics (MD) simulations show that water molecules interact with the PEGp to form a hydration layer, endowing PEGp hydrogel with hydrophilicity. These studies offer a novel approach to developing ship antifouling materials and exploring new directions for environmental protection and antifouling.

Biomimetic anti-fouling interface engineering based on thorn-vine-like structure for electrochemical sensing

Electrochemical sensing interfaces face an enormous obstacle posed by the non-specific adsorption in complex matrixes. This will decrease the current and sensitivity of electrochemical sensors. Since most biomarkers, especially those associated with diseases such as cancer, exist in trace amounts, sensitive detection is essential for them. However, it is a considerable challenge to develop anti-fouling interface strategies that can achieve highly sensitive electrochemical sensing in complex matrixes. Herein, a novel biomimetic anti-fouling interface engineering strategy was constructed based on thorn-vine-like structure for electrochemical biosensing. Bovine serum albumin (BSA) and sulfobetaine methacrylate (SBMA) underwent a thiol-ene click reaction, followed by electrostatic interaction with multi-walled carbon nanotubes (MWCNT), resulting in the thorn-vine-like structure BSA-PSBMA-MWCNT (BPSMC), with a highly three-dimensional network structure. The BPSMC not only significantly reduced non-specific adsorption, but also effectively enhanced the ability of the sensing interface to transfer electrons to the electrode surface. The impedance change ratio of the BPSMC-modified glassy carbon electrodes (GCE) was only 5.30% compared to the bare GCE when treated in undiluted serum samples for 2 h. As a proof of concept, the tumor biomarker ferritin (FER) was applied as a model analyte. By functionalizing the interface with specific antibodies, it enables quantification of FER in undiluted serum samples with ultra-high sensitivity. This biomimetic anti-fouling interface engineering strategy possesses excellent anti-fouling property, sensitivity, and universality and offers great potential for anti-fouling interfaces in complex matrices for medical and non-medical applications.

Fast-polymerized lubricant and antibacterial hydrogel coatings for medical catheters

Medical catheters are highly susceptible to friction and infection when intervening or implanting in the body, and to thrombosis when in contact with blood. Coating medical catheters with lubricant and antibacterial hydrogel is an effective strategy but struggle to achieve. Here, hydrogel coating on the catheter surface with lubrication and antibacterial properties was constructed by the rapid polymerization of acrylamide (AAM) and sulfobetaine methacrylate (SBMA) in the presence of quaternary ammonium chitosan (QCS) based on the redox-based cross-linking method. First, the medical catheter surface was decorated with a polyethyleneimine (PEI) adhesive layer. The pre-gel solution was then applied to the catheter surface, followed by immersion in an aqueous FeSO4·7H2O solution, where a large amount of SO4-• was generated by a redox reaction between ammonium persulfate (APS) and Fe2+, which rapidly triggered the monomer to cross-link to form the coating. Polyelectrolyte PEI as the adhesive layer could bind the coating to the substrate through hydrogen bonding interactions and confer antimicrobial properties to the coating with the assistance of QCS (antibacterial rate of 95.88 % against E. coli and 97.11 % against B. subtilis). The hydrogel coatings exhibited outstanding lubricity with a low coefficient of friction (COF ≈ 0.053) and excellent antifouling properties (resists non-specific protein adsorption, inhibits platelet adhesion and prevents thrombosis (The clotting time was extended from 25.6 s to 74.7 s)) based on the integration of SBMA. This work shed new light on the design of hydrogel coatings to achieve modification of the substrate surface.

Cysteine-based antifouling superhydrophilic membranes prepared via facile thiol-ene click chemistry for efficient oil-water separation

Superhydrophilic membranes with underwater superoleophobicity for oil-water separation have been attracted widely attention. Nevertheless, oil contamination of such membranes represents a pressing challenge in this field. Superhydrophilic/underwater superoleophobic membranes with surface zwitterionic moieties are proved to show excellent antifouling properties; however, such zwitterionic surface modifiers adopted previously usually face the problem of cumbersome synthesis relying on expensive reagents and complicated procedures, accompanied with poor acid/alkali resistance due to the unstable linkers, restricting their practical applications. Herein, we describe an alternative strategy for fabricating antifouling superhydrophilic/underwater superoleophobic membranes from a natural amino acid. Sand particle-based sintered glass membranes were firstly coated with silicone nanofilaments using vinyltrichlorosilane as a precursor through chemical vapor deposition; and then the surfaces of silicone nanofilaments were further functionalized with cysteine via thiol-ene click chemistry. The resulting membranes exhibited high separation flux and efficiency for gravity-driven separation of various oil-water mixtures and surfactant-stabilized oil-in-water emulsions. Moreover, such membranes displayed excellent antifouling properties and were reusable for the separation of oil-water mixtures and surfactant-stabilized oil-in-water emulsions. With the advantages of facile fabrication, low-cost, fouling resistance and high separation performance, we believe that cysteine-based glass membranes without any hydrolytic bonds will arouse tremendous attentions for oil-water separation.

Exceptional self-cleaning MXene-based membrane for highly efficient oil/water separation

Two-dimensional (2D) MXene-based separation membranes exhibit significant promise for oily wastewater treatment. The intercalation of TiO2 nanoparticles between MXene nanosheets can not only enlarge their interlayer distance for faster transportation of water molecules, but also promote their photocatalytic oxidation for removal of membrane fouling by oil droplets. However, the uniform loading of ultra-small TiO2 nanomaterials between MXene layers without aggregation is challenging. Herein, taking advantages of inherent Ti elements of MXene, we grew ultra-small TiO2 by in-situ one-step oxidation of MXene nanosheets to prepare 2D MXene@TiO2 heterojunctions. They were then loaded on polyethersulfone (PES) support by vacuum filtration for the PES-MXene@TiO2 composite membrane (MXTM) with exceptional water permeance and anti-fouling and self-cleaning properties. It achieves a remarkably high flux of 3045 L m−2 h−1·bar−1 and oil/water emulsion separation efficiency over 99.8%. Moreover, the MXTM membrane exhibits remarkable hydrophilicity, evidenced by an abrupt reduction in water contact angle from 43.8 to less than 5° within 10 s, which could retard the progress of oil adhesion on the membrane surfaces. The extended Derjaguin-Landau-Verwey-Overbeek theory confirmed high interaction energy between the membrane and pollutants. Furthermore, the MXTM membrane excels in self-cleaning and anti-fouling properties, retaining a flux recovery rate of >98% in 10 cycles by visible light driven photodegradation of foulants irradiation. This innovative 2D self-cleaning membrane offers excellent anti-fouling properties for efficient oil/water separation.

Reverse osmosis membrane with crown ethers decoration for enhanced radionuclides sieving

Reverse osmosis (RO) membranes have been widely applied in the increasingly discharged radioactive wastewater treatment. However, conventional RO membranes suffer from the issues of the limited nuclides rejections and the relatively low water permeance. In this work, a new type of RO membrane with decoration of crown ethers (15C5 and 18C6) was prepared via an interfacial polymerization process to remove the radionuclide-contaminated components. Due to the special hollow structure of crown ethers (CEs) and the hydrogen bonding within the amidogen, the obtained MPD@15C5-TMC and MPD@18C6-TMC membranes exhibited smoother surfaces and thinner polyamide active layers than the pristine MPD-TMC membrane. The optimized MPD@15C5-TMC and MPD@18C6-TMC RO membranes presented excellent pure water permeances up to 2.16 and 2.91 L m−2 h−1 bar−1, and maintained high rejections towards Cs+, Sr2+ and Co2+, respectively. Furthermore, the membrane possessed a remarkable operational stability and an excellent anti-fouling property. These results confirmed the possibility of adopting crown ethers for RO membrane fabrication and verified their great potential for the practical application in removing radioactive elements from wastewater.

Multifunctional polyurethane coatings with excellent antifouling and self-healing properties

Multifunctional polyurethane coatings with excellent antifouling and self-healing properties