Antifouling Performance Research Articles

Zwitterionic nanospheres engineered co-polymer composite membrane for precise protein-protein separation via dynamic self-assembly micelle deposition

The accurate protein-protein separation is important but technically challenging. Achieving such a precise separation using membrane requires the selective channels with appropriate pore geometry structure and high anti-fouling property. In this study, polyethersulfone-b-poly(sulfobetaine methyl methacrylate) (PES-b-PSBMA) was synthesized and engineered onto polysulfone (PSF) ultrafiltration (UF) membrane to fabricate zwitterionic nanospheres engineered co-polymer (ZN-e-CoP) composite membrane via dynamic self-assembly micelle deposition. On the one hand, self-assembly zwitterionic nanospheres were used as blocks to construct hydrophilic layers with size-dependent sieving channels, endowing ZN-e-CoP composite membranes with enhanced permselectivity and protein-protein separation abilities, meanwhile zwitterionic groups from nanospheres reinforced the structure stability of nanospheres/nanospheres and nanospheres/membrane via multiple intermolecular interactions. On the other hand, zwitterionic nanospheres can induce to produce the hydration layer enveloping themselves by binding water molecules, where hydration layer acts as a protective barrier on the membrane surface, impeding the protein adhesion. Hence, ZN-e-CoP_1a composite membrane exhibited superior separation properties with Lysozyme/Bovine Serum Albumin (BSA) separation factor of 18.1 and 95.4 % rejection against BSA, 10.1 and 2.3 times, respectively, higher these of pristine PSF membrane (1.8 and 42.1 %), without obviously sacrificing water flux. Simultaneously, hydration layer enables the ZN-e-CoP_1a membrane with enhanced anti-fouling performance and durability during the long-term operations. The proposed approach opens new pathways to fabricate excellent anti-fouling membranes for precise protein-protein separation.

Enhancing anti-fouling performance of ceramic membranes through iron oxide modification for the separation of oil-containing fermentation broth

Ceramic membranes are increasingly recognized for their effectiveness in processing fermentation broths. However, developing ceramic membranes with superior anti-fouling properties remains a challenge for large-scale applications. Iron oxide nanomaterials have gained significant research interest as a cost-effective and readily available solution for mitigating membrane fouling, thanks to their excellent hydrophilicity. This study introduces ceramic membranes enhanced with iron oxide via a facile sol-gel technique. The membrane's resistance to fouling, hydrophilicity, adhesion force, and surface potential were assessed. Post-modification, a consistent distribution of iron elements on the membrane surface was achieved, with negligible alteration in pore size. Although the pure water permeance (450 ± 45 L m−2 h−1·bar−1) did not change significantly, the permeance of the modified membrane (225 L m−2 h−1·bar−1) was nearly 20 % higher than that of the original membrane when separating a 1000 ppm oil-in-water emulsion, with both membranes achieving 99 % oil droplet rejection. Moreover, the flux recovery rate of the modified membrane surpassed that of the original membrane by approximately 30 %, indicating a significant improvement in anti-fouling performance. Upscaling experiments further validated the modified membrane's anti-fouling performance and capability to rapidly process broths with high oil content. Overall, this study presents a novel anti-fouling ceramic membrane for the treatment of oil-containing fermentation systems.

A rationally designed polymer brush/lubricant coating system for effective static and dynamic marine antifouling

Bioinspired slippery surfaces have garnered significant attention as promising solutions to mitigate biofouling. Unlike traditional lubricant-infused porous surfaces, recent research has focused on the integration of lubricants within polymer brush-grafted surfaces. The combination of polydimethylsiloxane (PDMS) polymer brush and silicone oil has gradually become the most prevalent choice due to their outstanding chemical affinity. However, this conventional coating system also has the potential for improvement to meet the needs of long-lasting and efficient marine antifouling, including i) precisely designing the polymer brush’s chemical structure to match the polarity of a specific lubricant enhances their chemical affinity, and ii) appropriately reduce the coating system’s surface energy to improve the fouling desorption performance. Here, we introduce a systematically engineered polymer brush/lubricant coating system that incorporates fluorinated polysiloxane and perfluoropolyether fluid. This novel coating system exhibits enhanced adhesion strength coupled with reduced surface energy, resulting in superior stability and omniphobic properties. Additionally, it showcases excellent corrosion resistance and significantly deters marine microorganism adhesion, achieving reductions of 98.8 % for P. tricornutum and 99.8 % for Bacillus sp.. Marine field trials, conducted over a 90-day static immersion period, confirm the remarkable antifouling performance, which surpasses most existing slippery coatings. Moreover, under dynamic conditions, organisms adhering for 150 days are readily dislodged by shear force. These findings underscore the pivotal role of systematic design in polymer brush/lubricant coating systems for the advancement of high-performance slippery surfaces tailored for marine antifouling applications.

Low MWCO non-polyamide nanofiltration membranes synthesized in aqueous by coupling with catechol-amine chemistry and the oxidation-induced self-polymerization of m-phenylenediamine

Catechol-amine coatings offer versatile routes for surface modifications and nanofiltration (NF) membrane preparations. However, the formation of the selective layer is time-consuming and often deficient, rendering it unsuitable for large-scale applications. In this work, oxidation-induced self-polymerization and catechol-amine chemistry were combined to rapidly construct nanofiltration membranes in an aqueous medium. M-phenylenediamine (MPD) underwent oxidation and self-polymerized on a polysulfone (PSF) support. The addition of sodium periodate facilitated the subsequent tannic acid (TA) coating. The catechol-amine reaction between oxidized TA and poly-MPD forms crosslinked poly TA-MPD complexes, offering the resulting membrane a high selectivity. The role of NaIO4 in the selective layer formation and the influences of the synthesis parameters on the membrane performance were discussed. Utilizing the facile method enabled the achievement of a low molecular weight cut-off (MWCO) NF membrane (180 Da). The membrane exhibited a high water permeance (10.9 Lm−2h−1bar−1) and good salt rejections (93 % for Na2SO4). The filtration of the bovine serum acid (BSA) solution demonstrated the membrane has good antifouling performance with a flux recovery ratio (FRR) of 95.1 %. The proposed method offers a straightforward and rapid approach to fabricating low MWCO NF membranes in an aqueous medium, which has potential in large-scale applications.

Preparation of polysulfone-based nanofiber Janus membrane for membrane distillation containing organic pollutants

Membrane distillation is an emerging wastewater treatment technology that harnesses low-grade heat as an energy source and exhibits potential for complete desalination. Nonetheless, two notable challenges hinder the practical application of this technology: membrane wetting and fouling. To counter these challenges, an innovative anti-fouling Janus membrane with asymmetric wettability was developed through electrospinning. The hydrophobic layer was formed using tetraethyl orthosilicate/polysulfone (PSF), and the superhydrophilic layer was created using polyvinylpyrrolidone (PVP)/PSF. A sensitive adhesion probe was used to assess the anti-fouling performance of the Janus membrane against oil. Molecular dynamics simulation suggested that PVP reduced the adsorption tendency of the membrane for humic acid (HA). Under experimental conditions involving saline water with HA and a saline oil–water emulsion, the non-Janus membrane suffered severe fouling, resulting in rapid water permeate flux decline. However, the Janus membrane demonstrated consistent permeate flux (26.84 LMH and 24.92 LMH) and an impressive salt rejection rate (> 99.99%). This study suggests that the Janus membrane, with its high permeate fluxes and remarkable resistance to fouling and wetting, could be an effective solution for wastewater treatment, with considerable potential for future application.

Synergistic Effect of Multilayered Alginate/Poly(SBMA) Coatings on Marine Antifouling Property.

Alginate (Alg) coatings have attracted attention as protective layers on solid surfaces for marine antifouling applications due to their strong water binding capability and environmentally friendly characteristics. However, the effectiveness of Alg coatings in preventing marine fouling diminishes upon interaction with divalent cations present in seawater. To address this issue, post-modification of the Alg coating is conducted. The carboxyl groups of Alg, which are susceptible sites for interaction with divalent cations, are conjugated with polymerization initiators through metal-mediated coordination bond formation. Subsequently, poly(sulfobetaine methacrylate) (poly(SBMA)) brushes are grown from the initiator-immobilized Alg coatings, resulting in the formation of multilayered Alg/poly(SBMA) coatings. In marine diatom adhesion assays using Amphora Coffeaeformis, multilayered Alg/poly(SBMA) coatings exhibited superior antifouling performance compared to single-layered Alg or poly(SBMA) coating controls.

Charge-induced aggregation of emulsified oil droplets in water with the presence of functionalized stainless steel felt

Oil-water mixtures, especially the surfactant-stabilized oil-in-water emulsions with high stability, are causing great difficulties in effective separation. In this work, a modification strategy was established to prepare functionalized stainless steel felt for emulsion separation by coating the felt with 3-triethoxysilylpropylamine, followed by the introduction of silica nanoparticles using a sulfur-based three-component coupling reaction. To satisfy the pore size requirement for effective emulsion separation, the developed felt was processed using a compression molding. With special wettability, optimized pore size, and electrostatic demulsification mechanism, the positive charged felt delivered outstanding separation capabilities for oil-in-water emulsions stabilized by various surfactants. Specifically, the flux and COD removal efficiency for the anionic-stabilized emulsion were up to 3911 L m-2h−1 and 95.3 %, while for cationic-stabilized emulsions, which were 1305 L m-2h−1 and 93.1 %. Our comparative results indicated that surface charges played an essential role in governing the separation performance of the felt, and the demulsification arising from the electrostatic attraction demonstrated better separation capability than that caused by the electrostatic repulsion. In addition, the developed felt showed controlled surface charge and anti-fouling performance under cyclic operations. The findings of this study are beneficial for constructing separation material with high separation efficiency and long-term durability for practical applications.

Scalable multifunctional MOFs-textiles via diazonium chemistry

Cellulose fiber-based textiles are ubiquitous in daily life for their processability, biodegradability, and outstanding flexibility. Integrating cellulose textiles with functional coating materials can unlock their potential functionalities to engage diverse applications. Metal-organic frameworks (MOFs) are ideal candidate materials for such integration, thanks to their unique merits, such as large specific surface area, tunable pore size, and species diversity. However, achieving scalable fabrication of MOFs-textiles with high mechanical durability remains challenging. Here, we report a facile and scalable strategy for direct MOF growth on cotton fibers grafted via the diazonium chemistry. The as-prepared ZIF-67-Cotton textile (ZIF-67-CT) exhibits excellent ultraviolet (UV) resistance and organic contamination degradation via the peroxymonosulfate activation. The ZIF-67-CT is also used to encapsulate essential oils such as carvacrol to enable antibacterial activity against E. coli and S. aureus. Additionally, by directly tethering a hydrophobic molecular layer onto the MOF-coated surface, superhydrophobic ZIF-67-CT is achieved with excellent self-cleaning, antifouling, and oil-water separation performances. More importantly, the reported strategy is generic and applicable to other MOFs and cellulose fiber-based materials, and various large-scale multi-functional MOFs-textiles can be successfully manufactured, resulting in vast applications in wastewater purification, fragrance industry, and outdoor gears.

β-cyclodextrin modified GO ultrafiltration membranes with enhanced antifouling property for water purification

The study investigated the influence of additives on the fabrication of mixed matrix membranes comprising polyethersulfone (PES), with a specific focus on hydrophilicity, flux, morphology, and antifouling properties. Carboxymethyl modified β-cyclodextrin (CMβ-CD) was used to enhance the dispersion and hydrophilicity of graphene oxide (GO), leading to the formation of a hydrophilic and stable composite nanoparticle (CMCD@GO). The hydrophilicity (WCA <51.5°) and water flux (32.6 L m−2.h−1) of the modified PES membranes (MCDGO-x) were improved by the incorporation of CMCD@GO nanoparticles, while that of PES membrane was 79.7° and 10.6 L m−2.h−1. The rate of backscattered light intensity (ΔBS) of MCDGO-x suspensions remains stable, suggesting stable dispersion of CMCD@GO in organic solvents. Compared to the bare PES membrane, the MCDGO-x membrane exhibits a thinner active layer and a finger-like structure. The MCDGO-x membrane exhibited excellent naphthenic acids (NAs) rejection (>93.2%) due to reduced roughness and higher hydrophilicity, while the GO-modified PES membrane (MGO-5) exhibited lower NAs rejection (87.2%). Furthermore, the MCDGO-5 membrane showed higher flux recovery ratio (FRR) of 79.3% compared to MGO-5 membrane (68.5%) after three cycles, indicating the antifouling performance of MCDGO-x for NAs was significantly improved. The combination of CMβ-CD and GO enhance the flux and antifouling properties of PES ultrafiltration membranes, suggesting significant potential for applications in the purification of oil sands process water and the treatment of oily wastewater.

Impact of end groups of small molecules grafted to reverse osmosis membranes on their separation and antifouling performance

In this study, surface hydroxylation and methoxylation were employed to fabricate polyamide (PA) reverse osmosis (RO) membranes with enhanced permeability and antifouling performance. Diethanolamine (DEA) and bis(2-methoxyethyl) amine (BMEA) were grafted onto PA of RO membranes, and the impact of their end groups of hydroxyls and methoxyls on PAs were investigated. Benefiting from the increased surface hydrophilicity (particularly for the DEA-grafted RO) and the tailored cross-linking structure of PA layers, both DEA- and BMEA-grafted membranes showed high water permeance (1.58-fold than the pristine RO membrane) with highly competitive NaCl rejection of 99 %. The DEA-grafted membrane exhibited the enhanced antifouling performance against both positively and negatively charged foulants, while the BMEA-grafted membrane exhibited exceptional performance against small cationic foulants. Quantum chemistry simulations reveal that hydroxyl groups grafted on PA possess a relatively low binding energy with both positively and negatively charged small foulants, whereas methoxyl groups grafted on PA exhibited an exceptionally low binding energy with positively charged small foulants, which rendered them less likely to be adsorbed onto the corresponding grafted PA and to form a loose cake layer. Our study provides new insights into design of small molecules with different end groups used for the simple and effective modification of antifouling RO membranes.

In-situ grown ZnO-nanorods of slippery liquid-injected porous surface coating on Mg alloy with hydrophobic, durable, and anti-corrosion properties

In this work, an in-situ self-grown nano-ZnO/epoxy-based slippery lubricant liquid-injected porous surface (SLIPS) coating with a unique bilayer structure is reported to achieve robustness, hydrophobicity, and anti-corrosion properties. Dense epoxy coated ZnO nanoparticles are used as the anti-corrosion barrier layer. Self-grown ZnO nanorods provide a robust micro- and nano-rough porous structure. The lubricant perfluoropolyether (PFPE) is strongly locked into the porous structure via low surface energy material pretreatment and capillary effect. This SLIPS coating has a high water contact angle (WCA) value and has excellent repellency to various liquids. The SLIPS surface maintains a high contact angle of more than 115° even after 20 days of immersion in corrosive solutions and withstand the erosion of corrosive solutions with pH = 3. It also has a very low corrosion current density of 8.97 × 10−12 A/cm2 and the Rct (the charge transfer resistance) of optimum SLIPS remained 1.41 × 108 ohm cm2 after 70 days immersion in 3.5 wt% NaCl solution, which is in the same order of magnitude as the initial value. The SLIPS coating with excellent mechanical stability, super-hydrophobicity, anti-fouling, chemical stability, and long-term corrosion resistance performance possesses tremendous application potential in long-term corrosion protection of Mg alloys.

Enhanced permeability and antifouling properties of carboxylated polysulfone/quaternized polyimide blend ultrafiltration membrane

AbstractThe intricate interplay between chemical composition and the incorporation of functional fillers plays a pivotal role in shaping the structural attributes and separation efficacy of mixed matrix ultrafiltration membranes. In this work, we report the utilization of a novel organic filler of hydrophilic modified polyimide particles (PI‐SO3) for the first time in the preparation of mixed matrix ultrafiltration membranes. A series of ultrafiltration membranes were fabricated using polysulfone as the matrix material and PI‐SO3 as the additive. The addition of PI‐SO3 to the mixed matrix membrane effectively enhanced both water flux and antifouling ability. The ultrafiltration membrane with 0.2% particle content exhibited the highest pure water flux at 535.5 L h−1 m−2, owing to the synergistic regulation of pore structures and surface hydrophilicity. The ultrafiltration membrane with 0.5% PI‐SO3 particles demonstrated the highest flux recovery rate at 76.8%, attributed to the superior hydrophilicity displayed by the added particles within the ultrafiltration membrane. The increased particles content correlated with improved hydrophilicity on the membrane surface, resulting in enhanced antifouling performance. The hydrophilic modified particles effectively regulated pore structures, surface hydrophilicity, and surface charge, ultimately enhancing the performance of mixed matrix ultrafiltration membranes for wastewater purification. Therefore, the use of modified polyimide particles as fillers introduces an innovative method to economically enhance ultrafiltration membranes, providing a potential solution to mitigate the economic costs associated with trade‐off effects during the modification process.

NIR-Driven Self-Healing Phase-Change Solid Slippery Surface with Stability and Promising Antifouling and Anticorrosion Properties.

Slippery liquid-infused porous surfaces (SLIPSs) have great potential to replace traditional antifouling coatings due to their efficient, green, and broad-spectrum antifouling performance. However, the lubricant dissipation problem of SLIPS severely restricts its further development and application, and the robust SLIPS continues to be extremely challenging. Here, a composite phase-change lubricant layer consisting of paraffin, silicone oil, and MXene is designed to readily construct a stable and NIR-responsive self-healing phase-change solid slippery surface (PCSSS). Collective results showed that PCSSS could rapidly achieve phase-change transformation and complete self-healing under NIR irradiation and keep stable after high-speed water flushing, centrifugation, and ultrasonic treatment. The antifouling performance of PCSSS evaluated by protein, bacteria, and algae antiadhesion tests demonstrated the adhesion inhibition rate was as high as 99.99%. Moreover, the EIS and potentiodynamic polarization experiments indicated that PCSSS had stable and exceptional corrosion resistance (|Z|0.01Hz = 3.87 × 108 Ω·cm2) and could effectively inhibit microbiologically influenced corrosion. The 90 day actual marine test reveals that PCSSS has remarkable antifouling performance. Therefore, PCSSS presents a novel, facile, and effective strategy to construct a slippery surface with the prospect of facilitating its application in marine antifouling and corrosion protection.

Preparation of a novel LC@MWCNTs membrane and its application for enhanced phosphate removal and fouling control

To control the eutrophication originating from phosphate discharge, a novel adsorptive membrane was prepared by vacuum filtrating lanthanum carbonate modified multi-walled carbon nanotubes (LC@MWCNTs) on the UF membrane. The LC@MWCNTs were firstly made using an in-situ method by adding MWCNTs to LaCl3·7H2O solution and forming lanthanum carbonate under alkaline conditions. The adsorption experiments exhibited that the maximum adsorption capacity of LC@MWCNTs was 77.58 mg P/g at pH 5. And the phosphate adsorption by LC@MWCNTs was not predominantly reliant on electrostatic interaction, but rather achieved through chemical interactions. Then, the prepared LC@MWCNTs membrane was systematically evaluated for its phosphate removal efficiency and anti-fouling performance during filtration. With the initial phosphate concentration of 1 mg P/L and membrane flux of 378 L·m−2 h−1, the phosphate removal by LC@MWCNTs membrane approached almost 100 %. Moreover, the LC@MWCNTs membrane exhibited higher permeability (281.6 L·m−2h−1bar−1) and effectiveness for humic acid (HA) removal (75 %), and LC@MWCNTs membrane mitigated the fouling caused by HA. XPS, FTIR and XRD elucidated that phosphate removal by LC@MWCNTs membrane primarily through the formation of La-O-P inner-sphere complexes via ligand exchange, resulting in the formation of adsorption product LaPO4·0.5H2O. Under strong alkaline conditions, the LC@MWCNTs membrane rapidly restored its phosphate removal performance (30 min) with no significant detachment of the LC@MWCNTs layer, indicating its good recovery and reusability performance. Additionally, the LC@MWCNTs membrane could continuously remove phosphate from actual water, confirming its potential for future practical applications.

Fluorescent zinc acrylate resins containing coumarin structures with enhanced antifouling performance

The demand for non-toxic antifouling coatings has led to the development of multifunctional antifouling coatings. In this work, a series of coumarin acids with fluorescence were first prepared via the Knoevenagel condensation reaction. Then, multifunctional zinc acrylate resins were produced successfully by employing an acrylic acid monomer, ZnO, and coumarin acids by free radical polymerization and polycondensation processes. The self-polishing and antifouling properties of the resins were investigated by dynamic simulation experiments, E. coli growth inhibition experiments, algae adhesion inhibition experiments, and marine environment antifouling experiments. The results show that the zinc acrylate resins containing the coumarin structures not only have good self-polishing performance but also have better antifouling performances than the zinc acrylate resin containing benzoic acid. This work not only reveals the antifouling mechanism of the multifunctional resins, but also provides a new strategy for the development of environmentally friendly antifouling coatings.

Ethanol activation of polyester membrane for superior dye/salt separation performance

Dye wastewater poses a severe danger to the environment and human health. The purification of dye wastewater is the focus and hotspot of most researchers. In this work, ethylene glycol (EG) was selected as an aqueous phase monomer to fabricate polyester membranes through an interfacial polymerization reaction. Then the polyester membrane was activated by ethanol aqueous solution. By adjusting the activation time and concentration of the ethanol, the network of the polyester membrane can be reshaped to endow the membrane with excellent performance. The activation mechanism was also explored here. Compared to the membrane without activation (PE-0%), the permeability of the optimized membrane (PE-40%) was increased by 8.3 times, and a high rejection was maintained (CR: 99.2%). Importantly, the PE-40% membrane also presented good acid and alkali resistance, chlorine resistance, and excellent antifouling performance. Our work provides an effective and feasible strategy for the development of high-performance polyester membranes.

Green maltitol-based nanofiltration membranes featuring high permeance and excellent anti-fouling performance for dye desalination

Polyester loose nanofiltration (LNF) membranes are ideal for achieving dye resource recovery. However, the low permeance and insufficient selectivity of dye/salts for polyester membranes remained a significant challenge. This work employed a low reactivity, hydroxyl-rich, non-toxic, inexpensive and renewable, and larger volume green material maltitol (ML) as an aqueous monomer for preparing high-performance polyester membranes. The ML-based membranes had a smooth surface with a considerable negative charge and strong hydrophilicity. The optimized ML-based membranes (ML-1.0/TMC) possessed remarkable water permeance (104.9 L m−2 h−1 bar−1) and excellent dye/salt selectivity (selectivity for CR/NaCl was 340). Additionally, the ML-1.0/TMC membrane demonstrated outstanding stability and excellent anti-fouling performance. The results indicated that the ML-based membranes had excellent performance in dye filtration tests, demonstrating the great potential of ML-based membranes for dye wastewater resource recycling.

Synergistic photocatalytic-photothermal contribution induced by Pd-TiO2/PEDOT immobilized in PVDF membrane for enhanced water purification

The photocatalytic membrane systems show great potential for water purification and wastewater treatment with efficient energy utilization. Herein, we develop a synergistic photocatalytic-photothermal route, based on Pd-TiO2/PEDOT composite immobilized in PVDF membrane, for effective water permeability and reutilization property. Novel Pd-TiO2/PEDOT/PVDF ultrafiltration membrane is prepared by the phase inversion method with immobilizing Pd-TiO2/PEDOT obtained by ultrasonic irradiation. During the removal of HA under light irradiation, Pd-TiO2/PEDOT/PVDF membrane presents an unexpected increasing in water flux, when compared to pristine PVDF, Pd-TiO2/PVDF and PEDOT/PVDF membranes, with the highest normalized flux reaches up to 2.1 and remains as 1.3 even after 300 min of irradiation. This significantly enhances the water transport, along with the achieved high rejection and anti-fouling performance. It can be attributed to synergistic photocatalytic-photothermal effect of Pd-TiO2/PEDOT, which is realized by their strong interaction and uniform distribution. The addition of PEDOT promotes photocatalytic effect of Pd-TiO2 by enhancing separation of photo-induced charges. High photothermal conversion efficiency of Pd-TiO2/PEDOT and low temperature difference in Pd-TiO2/PEDOT/PVDF membrane facilitate effective thermal storage, beneficial for water transport. Meanwhile, thermal energy promotes generation of more ∙OH and ∙O2– radicals to remove pollutants. Synergistic photocatalytic-photothermal contribution in Pd-TiO2/PEDOT/PVDF membrane shows significant potential for practical application.

Cross-flow photocatalytic membrane reactor (PMR) based on TiO2–AgBr–Ag–NH2-MIL-88B (Fe) /poly (ethersulfone) for enhanced removal of cefixime, anti-fouling performance and permeability

The organic-metallic framework NH2-MIL-88B (Fe) was initially synthesized using a hydrothermal process., then the TiO2–AgBr–Ag–NH2-MIL-88B (Fe) photocatalytic nanoparticles was successfully ready and used as a filler for mixed matrix membrane (MMM) poly Ether sulfone (PES) was added. A photocatalytic membrane reactor (PMR) for the degradation of cefixime aqueous solution (CFX) was fabricated using a PES-TiO2-AgBr-Ag–NH2–MIL-88B (Fe) flat sheet membrane module. FTIR, XRD, FESEM, and DRS analyses were performed to look into the produced nanoparticles' structural characteristics. Hydrophilicity and membrane surface roughness were investigated using the surface contact angle and AFM pictures test. Additionally, Cross-FESEM analysis was used to examine modifications in membrane morphology. By increasing the TiO2–AgBr–Ag–NH2-MIL-88B (Fe) nanoparticles in the polymer matrix, significant improvements were made to the membrane's hydrophilicity, porosity, pure water flux, and CFX degradation. Furthermore, the nanocomposite membranes' antifouling characteristic was assessed while the CFX solution was being filtered. The obtained results show that the flux and removal of CFX solution is improved by adding TiO2–AgBr–Ag–NH2-MIL-88B (Fe) nanoparticles to PES polymer solution up to 1 % by weight. In addition, the obtained results showed that the addition of TiO2–AgBr–Ag–NH2-MIL-88B (Fe) photocatalytic nanoparticles in the PES membrane significantly improves the antifouling properties.

Combined antibacterial and antifouling properties of polyethersulfone mixed matrix membranes with zwitterionic graphene oxide nanostructures

AbstractThe impact of zwitterionic graphene oxide (GO‐Arg) nanostructures into polyethersulfone (PES) membranes was studied, aiming to perform mixed matrix membranes (MMMs) with combined antibacterial and antifouling properties. For this purpose, 0.25, 0.50, and 1.0 wt% of GO‐Arg were incorporated through the phase inversion method. The chemical composition reveals that the electrostatic interactions of PES, polyvinylpyrrolidone, and GO‐Arg occur by enhancing the CH/NH vibrations associated with the intrinsic MMMs and their combined antibacterial and antifouling performance. Well‐defined finger‐like morphology was observed, performing the pore distribution and the finger‐cavity inclination induced by the electrostatic charge of GO‐Arg. As a result, GO‐Arg MMM's hydrophobic properties decreased from 77.8° to 52.3°, inducing a partially hydrophilic surface and improved water flux. The isoelectric point of nanostructured membranes slightly changes by the charge modulation produced by zwitterionic GO‐Arg. The antibacterial activity against Gram (−) Escherichia coli was improved, closing the complete bacterial inhibition after 24 h. As a result, antifouling performance was improved, avoiding bacterial adhesion into the membrane surface and the possibility of promoting biofilm formation. Our results demonstrate that zwitterionic nanomaterials in MMMs perform the multifunctional capacity of materials, emerging as an effective alternative with potential application in wastewater treatment.Highlights The incorporation of zwitterionic GO‐Arg improves the mechanical properties of MMMs. GO‐Arg‐enhanced well‐defined porous finger‐like morphology in MMMs. GO‐Arg improves the antibacterial/antifouling performance of PES‐based MMMs.