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This study presents the main method of in situ reduction for the preparation of Poly(vinyl chloride) coated membrane with silver nanoparticles by using cloves aromaticum extract as a reducing and stabilizing agent. Scanning Electron Microscopy (SEM), X-ray diffraction, and UV–Vis spectroscopy were used to analyze the structure and grain size of the produced particles. SEM study was appeared that no significant difference in the morphology of uncoated and coated membranes. However, some substance on the surface of the Poly(vinyl chloride) coated membranes was recognized as AgNPS. The antimicrobial activity of coated membrane and AgNP solution was investigated against Escherichia Coli (E. coli) by using disk diffusion and well diffusion test. As a result AgNP have high inhibition zones for each concentration.

Membrane distillation (MD) is a thermal technology for the desalination process that requires a hydrophobic microporous membrane to ensure that the membrane can maintain the liquid–vapor interface. This work aims to enhance the water permeation flux of the previously coated membrane by modifying the surface of the polytetrafluoroethylene hollow fiber (PTFE HF) membrane with a selected non-solvent such as acetone, cyclohexanone, and ethanol in low-density polyethylene as a polymeric coating solution. However, the modification using acetone and cyclohexanone solvents was unsuccessful because a reduction in membrane hydrophobicity was observed. The modified PTFE HF membrane with ethanol content exhibits high wetting resistance with a high water contact angle, which can withstand pore wetting during the direct contact MD process. Since MD operates under a lower operating temperature range (50–90 °C) compared to the conventional distillation, we herein demonstrated that higher flux could be obtained at 7.26 L m–2 h–1. Thus, the process is economically feasible because of lower energy consumption. Performance evaluation of the modified PTFE HF membrane showed a high rejection of 99.69% for sodium chloride (NaCl), indicating that the coated membrane preferentially allowed only water vapor to pass through.

The anammox process has been used for side-stream nitrogen removal. Mainstream anammox is challenging, however, as a result of low ammonium concentrations and retention times that wash out slow-growing anammox bacteria. To overcome these challenges, hollow fiber membranes with zeolite-coated surfaces were prepared to create near-surface microenvironments that mimic attributes of side-stream treatment systems. Results showed that in mainstream-type media, zeolite-coated membranes enhanced the growth of anammox bacteria on the membranes and in the bulk liquid of the reactor compared to reactors containing uncoated control membranes. The zeolite-coated membranes also improved the average total nitrogen (TN) removal to 73 ± 10% compared to 1 ± 49% in the control reactors. Additional experiments containing zeolite particles demonstrated that increasing zeolite mass increased the number of anammox gene copies present and improved TN removal, with effluent TN concentrations decreasing from 51.8 ± 5.9 to 7.78 ± 2.6 mg-N/L (P = 0.00085) as zeolite increased from 0.05 to 1.0 g/reactor, respectively. These results suggest that membranes/surfaces containing a greater quantity of zeolite should further improve retention of anammox bacteria and TN removal. Application of such membranes in an integrated fixed-film activated sludge (IFAS)-type system or membrane-aerated biofilm reactor (MABR) with intermittent aeration and low bulk DO concentrations should facilitate mainstream anammox.

In this work, a hollow glass fibre membrane was prepared and coated with a ZrO2 sol by dip coating. The ZrO2 sol coating adhered to the pristine membrane through interfacial interactions, as determined by FTIR spectroscopy and XPS analyses. The N2 adsorption-desorption curves indicated that the pores of the pristine and coated membranes formed by the accumulation of glass powder and ZrO2 sol layers, as determined from the H1 and H4 hysteresis loops, respectively. Thin and dense coating layers were observed on the surface of the coated membranes. Contact angle measurements showed that the hydrophilicity of the coated membranes remained almost constant. Furthermore, compared with the pristine membrane, the coated membranes exhibited higher rejection. The water flux and rejection varied within a narrow range even when separation was performed using the coated membrane for 12 h. The coated membrane with long-term stability demonstrates a good application prospect for highly efficient wastewater treatment.

2D Molybdenum disulfide (MoS2) nanoplatelets were synthesized via a green bottom-up strategy using non-toxic l -Cysteine as sulfur source. The hydrophobic MoS2 nanoplatelets assisted by hydrophilic 3-(3, 4-dihydroxyphenyl)-l-alanine ( l -DOPA) were coated on a thin film composite nanofiltration (TFC-NFG) membrane. The accelerated fouling experiments were conducted by using bovine serum albumin (BSA) as model organic foulant, and MoS2 coated membrane demonstrated excellent resistance with almost no flux decline within first hour of filtration, whereas the uncoated membrane showed flux decline immediately from the beginning of the experiment. After 5-hour filtration, the flux reduced by only 26% for MoS2 coated membrane with a higher flux recovery rate of 85.4% after washing by de-ionized (DI) water, whereas 45% flux decline was observed for uncoated membrane with lower flux recovery of 68%. These antifouling effects attributed by MoS2 coated membrane were underpinned by combined unique interfacial properties offered by 2D tri-atomic layered MoS2 morphology including dispersive surface tension, reduced surface roughness, weaker MoS2-foulant interactive forces, and negatively charged surface. This research positively confirms the role of 2D MoS2 nanoplatelets as an anti-fouling coating on membranes and brings up more possibility for applying other nanomaterials in 2D family in water applications such as desalination and water treatment.

Micro-porous layer (MPL) is the key component in proton exchange membrane fuel cell for water management. Electrospinning technique, providing a novel nanofiber structure, is recently used to fabricate MPL which gave improved fuel cell performance at normal temperature operation. However, underlying causes are not well understood, and no attempt has been made to study its effects on the cold start performance. In this work, electrospun MPL using non-toxic solvent was fabricated, and water management characteristics under both normal temperature and cold start conditions were compared with commercial MPL using the same catalyst coated membrane (CCM). Electrospun MPL outperformed the commercial MPL at 70 °C under high relative humilities due to marked reduction in mass transport losses. Under cold start conditions, fuel cell with electrospun MPL generated electricity for a longer time, possibly due to better interfacial connection, which facilitated water removal from catalyst layer.

The cell membrane-coated nanoparticles (MNPs) showed great potential in treating infectious disease due to their superior biofunctions in improving biocompatibility of nanoparticles and neutralization of pathogen or toxins. However, bone infection is accompanied with severe inflammation and bone loss, which also requires anti-inflammatory and osteoconductive treatment. The conventional membrane coating method has to undergo ultrasonication and extrusion procedures, which reduces the functionality of cell membrane and limits the choice of nanoparticles. In this study, we proposed an electroporation-based membrane coating strategy to facilitate the synthesis of MNPs to tackle those problems. Methods: Magnetic composite nanoparticles with osteoconductive Ca3(PO4)2 and bactericidal TiO2 were assembled into macrophages through phagocytosis and then collected to expose in electric field for obtaining macrophage membrane-coating nanoparticles. By using molecular dynamics simulation and materials characterizations, the cell membrane coating efficiency was confirmed. The in vitro anti-bacterial and anti-inflammatory abilities were tested by bacteria culturing and immune cells activation. Then drug-resistant bacteria induced bone infection model was established to verify its in vivo therapeutic effects. Results: The coated membrane prepared through electroporation reserved the integrality of membrane structure and right-sidedness, with more functional proteins. Those led to the superior properties of recognition and adsorption with bacteria, toxins and inflammatory cytokines. Owing to the benefits of electroporation, the MNPs exhibited significant better antibacterial and anti-inflammatory abilities for enhancing the tissue repair process. Conclusion: This study provides a novel self-assembly cell membrane coating strategy by electroporation to construct multifunctional membrane-coating nanoparticles for bone infection treatment. This strategy not only improves the functions of coated membrane, but is also proved to be universal for varies nanoparticles or cells, indicating a great potential for future applications in the bioengineering field.

The shuttle effect of polysulfides severely blocks the cycling performance and commercial application of lithium–sulfur (Li–S) batteries. Recently, metal–organic frameworks (MOFs) with abundant porosity, nanometer cavity size, and high specific surface areas have been considered to be an effective material in inhibiting polysulfide diffusion. However, the insulation properties of MOFs and the reuse of dissolved polysulfides are still challenging. Hence, in this study, a fluorine doped ZIF-8 derived porous carbon is designed and applied as a membrane modifier to mitigate the shuttle effect and maximize reuse of the dissolved polysulfides. A comparative study of a bare membrane, ZIF-8 carbonized material (N–C-1000) coated membrane and fluorine doped ZIF-8 derived porous carbon (F–N–C-1000) coated membrane was performed. The experimental results prove that a layer of ZIF-8 derived porous carbon coated membrane does improve the capacity and cycling stability. The results also show that the optimal candidate with enhanced capacity and cycling stability should be mainly ascribed to physical adsorption (abundant porosity), chemical adsorption (fluorine and nitrogen doping) and even reuse of dissolved polysulfides by the modified membrane.

In many works of literatures, the performance of carbon nanotubes as Pt support has been studied in the oxygen reduction reaction (ORR). Here we demonstrate the impact of these carbon nanotubes after modification by nitrogen groups to improve the performance of ORR in PEM fuel cell applications. In this regard, the characterization results of bare (MWCNTs), and functional groups of nitrogen by triethylenetetramine (MWCNTs-TETA), diethylenetriamine (MWCNTs-DETA) and malononitrile (MWCNTs-MN)precursor were presented and then the electrochemical analysis of Pt nanoparticles depositing on them are studied. The role of nitrogen functional groups on the activity and stability of Pt nanoparticles is investigated. These parameters are investigated using catalyst coated membrane electrode (CCME) which is placed inside a homemade cathodic half-cell. The CCME is prepared with a Nafion 117 membrane and gas diffusion layer (GDL) having an active area of 0.785 cm2. The half-cell test results show that Pt/MWCNTs-TETA electrode had the highest ORR performance of 64.48 mW cm−2, while showed the lower ECSA drop than Pt/MWCNTs.

In the present study, commercial PES, PVDF, PTFE ultrafilter membranes, and two different nanomaterial (TiO2 and TiO2/CNT composite)-covered PVDF ultrafilter membranes (MWCO = 100 kDa) were used for the purification of an industrial oil-contaminated (produced) wastewater, with and without ozone pretreatment to compare the achievable fouling mitigations by the mentioned surface modifications and/or pre-ozonation. Fluxes, filtration resistances, foulings, and purification efficiencies were compared in detail. Pre-ozonation was able to reduce the total filtration resistance in all cases (up to 50%), independently from the membrane material. During the application of nanomaterial-modified membranes were by far the lowest filtration resistances measured, and in these cases, pre-ozonation resulted in a slight further reduction (11–13%) of the total filtration resistance. The oil removal efficiency was 83–91% in the case of commercial membranes and > 98% in the case of modified membranes. Moreover, the highest fluxes (301–362 L m−2 h−1) were also measured in the case of modified membranes. Overall, the utilization of nanomaterial-modified membranes was more beneficial than pre-ozonation, but with the combination of these methods, slightly higher fluxes, lower filtration resistances, and better antifouling properties were achieved; however, pre-ozonation slightly decreased the oil removal efficiency.

A novel microextraction technique was developed for aromatic amines using gold nanoparticles coated membrane. The preparation of the extraction device involves with the synthesis of gold nanoparticles via the reduction of AuCl3 by hydroxyethyl cellulose followed by coating to the polyethersulfone membrane. The simple extraction procedures involved placing the extraction device in a stirred aqueous sample solution, followed by desorption in an organic solvent using ultrasonication. The extract was analyzed by high performance liquid chromatography. Optimal extraction conditions include 50 min extraction time, 20 min desorption time, 30 mL sample volume, sample pH 10, 5 % NaCl content and 17 mg sorbent mass coupled with 100 μL desorption solvent. The performance of the extraction device in the absence and presence of gold nanoparticles was investigated. Enrichment factors ranged from 148 (for 3-nitroaniline) to 200 (for 3,4- dichloroaniline). The calibration results exhibited good linearity (r2 = 0.9931-0.9988) within the range 0.5-20 μg/L. The limits of detection were 0.3-0.7 μg/L and RSDs (n = 6) 10-19%. Comparison was made with solid-phase extraction. The method was subsequently applied to municipal wastewater samples. The proposed microextraction method offers advantages such as easy operation, high recovery, faster extraction, minimal use of organic solvent and elimination of tedious solvent evaporation and reconstitution steps.

Controlling the shuttling of lithium polysulphides (LiPS) to enhance the utilization of elemental sulfur has been considered as an important issue to improve the energy density and coulombic efficiency of lithium–sulfur batteries. The present work is aimed at demonstrating a simple preparation of a bi-functional trilayer membrane by coating Li7La3Zr2O12 and activated carbon on either side of the commercial membrane (Celgard 2320). The coated membrane was characterized by ionic conductivity, thermogravimetric and contact angle analyses. In the trilayer membrane, each component acts for a particular purpose: the activated carbon not only acts as a barrier for the migration of polysulfide but also provides additional pathways for electron transport for the insulating sulphur cathode, while the porous Celgard separator facilitates the migration of lithium ion, and the Li7La3Zr2O12 not only promotes the lithium ion migration by percolation but also prevents polysulfide shuttling via the electrostatic repulsive force. The coated membrane offered higher ionic conductivity and thermal stability compared to the uncoated one. The lithium–sulfur battery with the coated separator delivered higher specific discharge capacity than the uncoated separator. XPS studies revealed the absence of polysulfide deposition on the lithium metal surface after the charge–discharge cycling, which further confirms the suppression of polysulfide shuttling by permselective membranes.

Advanced nanoporous membranes with outstanding permeance and exceptional molecular-separation efficiency are highly desirable for key industrial applications for alleviating the worldwide environmental/energy crisis. Herein, an ultra-thin trinity coating (∼33 nm) for unparalleled molecular separation is first built via covalent bond (CB)/coordination bond (COB) competitive reactions. The COBs generated among various polyphenols (PPhs), amino substances (ASs) and transition metal ions (TMIs) can limit Michael addition or Schiff base reactions for CB formation between PPhs and ASs during the mussel-inspired ternary coating process so as to elegantly engineer the trinity coating architecture on the porous substrate with ultra-thin thickness, excellent structural integration, high hydrophilicity and outstanding smoothness. Our molecular separation nanoporous membrane demonstrates ultra-high permeance (114 L m−2 h−1 bar−1 for Bromothymol Blue (BTB) and 104 L m−2 h−1 bar−1 for Congo Red (CR)) with complete rejection, which is much superior to that of state-of-the-art membranes and can realize the lower energy consumption of the membrane separation process. The CB/COB competitive reactions drastically enhanced the permeance of the trinity coated membrane by 533%, 238%, and 93% compared to that of the unary (pDA) and binary (pDA/PEI or pDA/Co2+) coated membranes. Meanwhile, the novel membrane with the perfectly tuned architecture by CB/COB competitive reactions possesses extraordinary dye/salt selectivity, tremendous acid/alkali–base stability and excellent anti-pollution capacity simultaneously. The new strategy for building an outstanding trinity coating via competitive reactions can pave a realistic way for fabricating unparalleled next-generation separation membranes.

Lithium–sulfur (Li–S) batteries are considered as futuristic energy storage systems owing to their high theoretical energy density, environmental benignity, and relatively low cost. However, their practical applications are still hampered by the insulating nature of elemental sulfur and the capacity degradation resulting from lithium polysulfide (LiPS) shuttling. Herein, we demonstrate the use of a porous organic polymer-coated Celgard 2320 (POP-CG) separator as the permselective membrane that is capable of not only delivering a higher discharge capacity but also preventing self-discharge of the Li–S cell up to 116 h which is superior compared to earlier reports. This coated membrane not only offers a higher discharge capacity but also exhibited superior wettability and thermal stability. The enhanced electrochemical properties of the lithium–sulfur cell are mainly attributed to the POP coated on the separator which effectively confines polysulfides via chemical interactions.

Objective: Currently, the foreign surfaces of extracorporeal circulation devices are coated with an acrylate-based copolymer that creates a hydrophilic blood-contacting layer to enhance biocompatibility. Several reports of acrylate-based copolymer with respect to biocompatibility have been published; however, the adsorption of peptide compounds on acrylate-based copolymer–coated membranes still requires clarity. In this study, we aimed to understand the adsorption of several peptide compounds of various molecular weights, including albumin, lysozyme, and vancomycin, on acrylate-based copolymer–coated membranes using in vitro studies. Methods: Six experimental circuits consisting of acrylate-based copolymer–coated tubes and membranes, and six comprising acrylate-based copolymer–coated tubes and non-coated membranes were prepared for comparison. An experimental solution, composed of albumin, lysozyme, vancomycin, and saline, was continuously stirred in a reservoir, recirculated in each experimental circuit, and then filtered. Concentrations of albumin, lysozyme, and vancomycin were measured after 0, 15, 30, 45, 60, 90, and 120 min of recirculation. Similar experiments were performed in all the prepared circuits. Results: The ratio of measured values at each time point to those at 0 min was not significantly different between acrylate-based copolymer–coated and non-coated membranes for albumin and lysozyme, but differed significantly for vancomycin; the ratios were higher in acrylate-based copolymer–coated than in non-coated membranes. Conclusion: This study suggests that albumin is not adsorbed on either acrylate-based copolymer–coated or non-coated membranes, that lysozyme is not adsorbed on either membrane or is adsorbed at a similar rate on both membranes, and that vancomycin is less adsorbed on acrylate-based copolymer–coated membranes. Thus, acrylate-based copolymer coating could inhibit the adsorption of various peptide compounds.

The membrane electrode assembly was prepared by a catalyst coated membrane (CCM) with an effective active area of 10 × 10 cm2 in this work. Porous titanium plates with different diameters were used as anode collectors to study the polarization curve and electrochemical impedance spectroscopy (EIS) of the electrolyzer. The results show that the pore size of a porous titanium plate on the anode side has a significant effect on the performance of the electrolyzer. The best cell performance was obtained when the median diameter of the anode titanium plate was 12.3 um. When the current density is 1 A/cm2, the battery voltage is 2.253 V.

Catalyst layers (CL), as an active component of the catalyst coated membrane (CCM), form the heart of the proton electrolyte membrane fuel cell (PEMFC). For optimum performance of the fuel cell, obtaining suitable structural and functional characteristics for the CL is crucial. Direct tuning of the microstructure and morphology of the CL is non-trivial; hence catalyst inks as CL precursors need to be modulated, which are then applied onto a membrane to form the CCM. Obtaining favorable dispersion characteristics forms an important prerequisite in engineering catalyst inks for large scale manufacturing. In order to facilitate a knowledge-based approach for developing fuel cell inks, this work introduces new tools and methods to study both the dispersion state and stability characteristics, simultaneously. Catalyst inks were prepared using different processing methods, which include stirring and ultrasonication. The proposed tools are used to characterize and elucidate the effects of the processing method. Structural characterization of the dispersed particles and their assemblages was carried out by means of transmission electron microscopy. Analytical centrifugation (AC) was used to study the state and stability of the inks. Herein, we introduce new concepts, S score, and stability trajectory, for a time-resolved assessment of inks in their native state using AC. The findings were validated and rationalized using transmittograms as a direct visualization technique. The flowability of inks was investigated by rheological measurements. It was found that probe sonication only up to an optimum amplitude leads to a highly stable colloidal ink.

The phosphatidylinositol-3-kinase (PI3K)-Akt signaling axis controls cell survival, proliferation and metabolism, and is activated by receptor tyrosine kinases (RTKs) such as the epidermal growth factor (EGF) receptor (EGFR). In addition to activation of PI3K-Akt signaling, the binding of EGF to its receptor results in rapid recruitment of EGFR to clathrin-coated pits (CCPs) followed by eventual EGFR internalization. Hence, receptor-proximal activation of signaling intermediates occurs while EGFR resides within CCPs; however, whether CCPs are required for EGFR signaling remains poorly understood. Using a combination of pharmacological inhibition and siRNA gene silencing of clathrin, we have examined how clathrin controls EGF-stimulated activation of Akt. We find that perturbation of clathrin, but not of EGFR endocytosis by perturbation of dynamin leads to disruption of EGF-stimulated Akt phosphorylation. This indicates that clathrin acts in a function separate from its role in endocytosis to regulate EGFR signaling at the plasma membrane. The EGF-stimulated phosphorylation of the signaling intermediate Gab1, but not that of EGFR itself, was also abrogated upon disruption of clathrin. We then utilized total internal reflection fluorescence microscopy (TIRF-M) to examine the hierarchy of recruitment of EGFR signaling components to CCPs. Collectively, these findings suggest a role for clathrin as a central regulator of EGFR signaling leading to Gab1 and Akt phosphorylation.

MMP20 cleaves cadherins and may facilitate cell movement, however MMP20 is not known to cleave tight junction or desmosome proteins. Ameloblasts had not previously been screened for membrane anchored proteases that could contribute to cell movement. Here we performed a PCR screen for proteolyticlly active A Disintegrin And Metalloproteinase (ADAM) family members. These proteinases are termed sheddases because they have a transmembrane domain and their catalytic domain on the cell surface can function to release anchored proteins. Significantly, ADAMs can be targeted to specific substrates on the cell membrane through their interaction with tetraspanins. Six ADAMs (ADAM8, 9, 10, 15, 17, 19) were expressed in mouse enamel organs. We show that Adam10 expression begins in the apical loop, continues through the secretory stage and abruptly ends at the transition stage when ameloblast migration ceases. ADAM10 cleaves cadherins and tight junction plus desmosome proteins and is well characterized for its role in cell movement. ADAM10 facilitated LS8 cell migration/invasion through a Matrigel coated membrane and we demonstrate that ADAM10, but not ADAM17 cleaves the RELT extracellular domain. This striking result is significant because RELT mutations cause amelogenesis imperfecta (AI) and this directly links ADAM10 to an important role in enamel development.

One promising option for storing surplus electricity from renewable energy sources is the conversion of electricity to hydrogen by polymer electrolyte membrane (PEM) electrolysis and the subsequent storage of the hydrogen produced. In order to obtain good contact, the components of an electrolysis cell are compressed at a certain clamping pressure. However, too high of a pressure can have a negative effect on cell performance. This work discusses how clamping pressure affects the cell performance of different PEM electrolysis cell designs. A special test cell is designed that makes it possible to apply pressure directly onto the active area of the cell. Polarization curves are measured at different clamping pressures, while electrochemical impedance spectroscopy (EIS) is used to show the effect of pressure on performance losses. Above a critical clamping pressure of 2.5 MPa ohmic losses are found to rise. In addition, it is tested as to whether the clamping pressure remains constant over time. The results show that stress relaxation of the catalyst coated membrane (CCM) leads to a pressure loss and thus to a decline in performance. Therefore, not only is it shown that pressure is crucial for cell performance but also, for the first time, a mechanical effect is described as an element of the cell's degradation.

Water pollution is becoming a crucial problem posing a serious threat for living organisms. Recently, photocatalytic membranes are used to purify drinking water and have shown a great potential in efficient for water and wastewater treatment. This study was conducted to remove bisphenol A (BPA) from water. Ag-doped TiO2 nanoparticles were deposited onto ceramic hollow fiber support by facile dip coating method to produce photocatalytic Ag-doped TiO2 ceramic membrane. The nanoparticles were firstly synthesized via liquid impregnation method, while kaolin support was fabricated using phase inversion and sintering method. BPA was used to evaluate the photocatalytic performance of the coated ceramic membrane. The effect of deposition time (0–120 s) of Ag-doped TiO2 photocatalyst over the ceramic membrane on the photocatalytic efficiency of the ceramic membrane was investigated. The structural analysis of Ag-doped TiO2 ceramic membranes was performed through X-ray diffraction (XRD), which confirmed the anatase crystal phase of Ag/TiO2 nanoparticles over the ceramic membrane. The surface morphology was explored via field-emission electron scanning electron microscope (FESEM), and a significant change was observed in the surface morphology of the coated membrane over deposition time. The energy-dispersive X-ray analysis (EDX) was used to find the elemental composition. UV–visible absorption spectra indicate that the Ag/TiO2 nanoparticles were extended to the visible region. The photocatalytic BPA removal efficiency of 88% was exhibited by Ag/TiO2-coated TM-120 ceramic membrane (the membrane coated for 120 s) in 270 min under visible light. This research is useful for purification of drinking water through nanoparticle-coated ceramic membrane.

The application of membranes for clove oil purification has the potential to improve the efficiency and effectiveness of processing. The main problem that occurs is the polymer-based membranes tend to change in properties such as weakening, dissolving, and swelling when contact with clove oil. In this study, cellulose acetate membrane was developed with TiO2 nano-particles to reduce swelling effect and coating with polyvinyl alcohol (PVA) to modify membrane surface. The membranes were prepared using dry-wet phase inversion method from dope solution with polymer concentration of 14–20 wt% and nano-particles of TiO2 with a concentration of 0–1.5 wt% in total solid. The formed membrane was coated with PVA with a concentration of 2–5 wt% crosslinked using glutaraldehyde. The SEM results show that prepared membrane are asymmetric membranes and show the coated layer of PVA on the surface. The FTIR spectra confirm that the PVA is successfully crosslinked and the addition of nano-particles TiO2 decreases the membrane swelling degree, significantly. In the addition of 0.5 wt% of nano-TiO2 can increase the flux from 0.54 to 0.66 L × m−2 × h−1 × bar−1. The coated membrane surface using PVA increases the selectivity of the membrane to produce clove oil permeates with eugenol content of 82.5 % from 68 %.

The core of this study is utilization of the facile one-side self-polymerization of dopamine (DA) on surface of the non-recoverable polyethersulfone (PES) membrane and its antifouling ability assessment during oil-in-water (O/W) emulsion separation. The pristine PES membrane was coated by DA solution for 2 and 4 h. The membranes were characterized using FESEM, AFM, FTIR, water contact angle (WCA) and underwater oil contact angle (UOCA) analysis. The results showed that hydrophilicity and underwater oleophobicity can be achieved successfully. Antifouling properties of the modified membranes were improved so that water flux of the 4 h polydopamine (PDA) coated membrane increased about 793% in comparison to the pristine PES membrane. Also, implementation of classical models showed that PDA coating changes the membrane fouling mechanism from standard blockage model to cake filtration model. The 4 h PDA modified membrane shows antifouling property and easy recovery capability during 30 h of operation. Also, the dependences of steady-state water flux were investigated via changing initial oil concentration, feed salinity, trans-membrane pressure and self-polymerization time of DA. Self-polymerization time of DA was found as the most influential factor on water flux. Also, during O/W emulsion separation, all the membranes exhibited high removal efficiency (above 98%) introducing a promising candidate for practical applications.

A stable, platinum-free catalyst-coated anion-exchange membrane with a promising performance for alkaline water electrolysis as an energy conversion technology was prepared and tested. A hot plate spraying technique used to deposit electrodes 35 or 120 μm thick on the surface of an anion-selective polymer electrolyte membrane. These thicknesses of 35 and 120 μm corresponding to the catalyst load of 2.5 and 10 mg cm−2. The platinum free catalysts based on NiCo2O4 for anode and NiFe2O4 for cathode were used together with anion selective polymer binder in the catalyst/binder ratio equal to 9:1. The performance of the prepared membrane-electrode assembly was verified under conditions of alkaline water electrolysis using different concentrations of liquid electrolyte ranging from 1 to 15 wt% KOH. The electrolyser performance was compared to a cell utilizing a catalyst-coated Ni foam as the electrodes. The prepared membrane-electrode assembly stability at a current load of 0.25 A cm−2 was verified by a 72-hour electrolysis test. The results of the experiments indicated the possibility of a significant reduction of the catalyst loading compared to a catalyst-coated substrate approach.

A hydrogen-selective and hydrothermally stable membrane composed of silica-zirconia layer deposited on a modified alumina sub layer was successfully prepared. The composite membrane was used for hydrogen purification from synthesis gas in steam methane reforming process. Silica-zirconia layer was synthesized using the CVD method at 923K and atmospheric pressure while the alumina base layer was prepared via sol-gel procedure. DLS, XRD, SEM/EDX, and BET characterization techniques were used to prove that γ-alumina base and silica-zirconia layer are fabricated successfully. Using the composite membrane, hydrogen selectivity toward other gases has improved significantly. Moreover, H2/CH4, H2/CO, and H2/CO2 selectivity have been increased from 700, 350 and 70 in 5 h CVD synthesized membrane to 1600, 750 and 570 for 12 h CVD synthesized membrane respectively. The synthesized Silica-Zirconia membrane successfully altered gases permeability tendency order from H2 > CH4 > CO2 > CO to H2 > CO2 > CO > CH4 which leads to better separation of the product from methane feed. Finally, hydrothermal stability test demonstrated that permeability loss in silica-zirconia CVD coated membrane for H2 is 45.7% after 48 h, while for silica CVD coated on the modified alumina approaches 92.5%.

Low-cost, environmentally friendly superwetting materials are urgently desired in industrial oily wastewater situations. In our work, egg shell powders (ESP)-coated polyvinylidene fluoride (PVDF) m...

Development of anion-exchange membranes (AEMs) with selectivities among anions may expand the applications of these membranes in salt separations. This work shows that layer-by-layer coating of aliphatic polyamide AEMs with poly(4-styrenesulfonate) (PSS)/protonated poly(allylamine) (PAH) films enhances Cl−/SO42− dialysis selectivities, and the extent of this enhancement depends on the source-phase salt concentrations. For a source phase containing 0.01 M NaCl and 0.01 M Na2SO4 and a receiving phase of 0.01 M Na2CO3, a (PSS/PAH)5PSS coating (5 PSS/PAH “bilayers” capped with a layer of PSS) increases the Cl−/SO42− selectivity from 1.7 to 5.3 in diffusion dialysis and from 1.3 to 7.4 in electrodialysis. Remarkably, the diffusion dialysis selectivity of a coated membrane increases to 140 when the salt concentrations in the source phase are 0.1 M. Even with bare membranes, selectivity increases to 13 with 0.1 M source-phase salt concentrations. Moreover, AEMs coated only on the receiving side show much higher selectivities but lower fluxes than those coated only on the source side. Partitioning experiments and modelling suggest that the increased Cl−/SO42− selectivities at high source-phase salt concentrations stem from enhanced Cl− partitioning and electromigration that disproportionately decreases SO42− flux in the AEM.

An effective permeation reduction of gaseous hydrogen isotopes into a metal wall by introducing a barrier is essential in two main fields: prevention of hydrogen-embrittlement in steels and control of the tritium inventory in future nuclear fusion reactors. By far the most important advances and relevant studies originate from the Nuclear Fusion Community where tritium retention is an important issue, influencing safety issues.Stable permeation barriers are searched among materials with the lowest bulk hydrogen solubility and diffusivity. Besides a few specific pure metals, like beryllium and tungsten, dense oxides, nitrides and carbides have been mostly investigated. Coating techniques for preparation of well adhered and perfect barriers are evidently of the same importance as the material selection itself. Most attractive are the techniques where an ad-layer is formed simply by oxidation. Other methods require specific gas environments with strong electric and magnetic fields, which may represent a limit for the ad-layers uniform coverage over large and uneven areas. Evaluation of the achieved barrier performances is another challenging task. Several new methods, which can trace hydrogen isotopes in bulk at very low concentrations, often miss in the determination of their mobility. Also, they do not reveal the role of barrier defects. The classical gas permeation rate method through coated membranes is still the most reliable option to determine the actual Hydrogen Permeation Barrier (HPB) efficiency. At elevated temperature, the hydrogen permeation rate is recorded at the downstream side of a coated membrane exposed to a substantially higher hydrogen upstream pressure. By using modern vacuum instrumentation techniques, even the most effective barriers can be well characterised. Keywords: Hydrogen permeation barrier, Nuclear fusion, Oxides, Nitrides, Carbides

Compared to conventional proton exchange membrane (PEM) fuel cell with thick membrane electrode assembly, today’s automotive PEM fuel cell adopts thin MEA with thin catalyst coated membrane (CCM). The objective of this modeling study is to shed light on PEM fuel cell with thin MEA under low humidity operation condition. The effects of cathode catalyst oxygen reduction reaction activity and local O2 transport resistance on automotive PEM fuel cell high current operation are elucidated. The local O2 transport resistance is found to have large impacts on limiting current density. The effects of cathode humidifier elimination, operating pressure, and stoichiometry ratio on PEM fuel cell performance are also discussed. The thin membrane in thin MEA has much lower ohmic resistance compared with thick membrane, and it is easy to be hydrated under low humidity condition. But H2 crossover is stronger for thin membrane and needs to be watched out when thinning the membrane. In addition, a 50 cm2 PEM fuel cell with counter-cross flow field is simulated for demonstration of medium scale PEM fuel cell modeling. Under 0.65 V and 50%/0% humidity operating conditions, the 50 cm2 PEM fuel cell is predicted to supply average current density of 2.51 A/cm2.

Interactions between catalyst layers and membrane are known to influence the mechanical properties of catalyst coated membrane (CCM) composites used in fuel cells, and can further affect their fatigue-driven mechanical fracture — an important lifetime-limiting failure mode in automotive applications. Here, the fracture propagation phenomenon in CCMs is characterized through a series of ex situ experiments and microstructural investigations conducted across a range of stress, temperature (23-70 °C), and relative humidity (50–90%) conditions relevant to low-temperature polymer electrolyte fuel cells. In comparison to pure membranes, the crack propagation rates are slightly arrested in CCMs through mechanical reinforcement offered by the catalyst layers; however, the membrane layer still controls the overall crack growth trends through its temperature and humidity dependent ductile fracture characterized by confined yielding around the fracture surface. Local interfacial delamination and severe electrode cracking are found to accompany the CCM crack propagation, which aids membrane fracture by loss of local reinforcement. A Paris law based fracture modelling framework, incorporating the elastic-viscoplastic mechanical response of CCMs, is developed to semi-analytically evaluate one-dimensional crack growth rate during cyclic loading, and provides reasonably accurate predictions for the present ex situ problem.

The membrane filtration technology is considered as one of the most important approach for removal of hazardous substances from wastewater. Herein, we report a facile surface modification method for preparing a novel membrane via the codepositing tannic acid (TA), polyetheylenimine (PEI), and halloysite nanotubes (HNTs) on the surface of polyvinylidene fluoride (PVDF) membrane. The morphologies and chemical compositions of membrane were characterized by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS), indicating that the membrane was successfully modified by TA/PEI/HNTs. Compared with pristine membrane, the coated membrane shows the improved hydrophilicity and pure water flux (PWF). The membrane modified by TA/PEI/HNTs achieves higher dyes rejection with 90.7%, 92.8% and 96.0% for direct yellow, direct red and direct blue, respectively. Moreover, the treated membrane exhibits excellent anti-fouling performance after several cycles. In addition, removal capacity for heavy metal ion can be enhanced by the as-prepared membrane with introducing the TA/PEI/HNTs coating. This work provides a facile strategy to carry out the hydrophilic modification of membranes. We hope the as-prepared membrane would have some practical applications for wastewater treatment.

The catalyst layer (CL) is the most important component in proton exchange membrane fuel cell (PEMFC) performance. Owing the properties of proton exchanging of Nafion, catalytic activity of Pt and electron transfer of carbon support, electrodes are prepared with different amounts of Nafion content, Pt loading and Pt% which are the catalyst layer composition parameters. Here we demonstrate the impact of these parameters to improve the performance of oxygen reduction reaction (ORR) in PEM fuel cell applications. Nafion content, Pt loading and Pt:MWCNTs percent are varied from 11 to 33 wt%, 0.1–0.5 mg cm−2 and 10 to 30 wt%, respectively. These parameters are investigated using a catalyst coated membrane electrode (CCME) assembling technique which is placed inside an in-house cathodic half-cell. Half-cell setup is used as an ex situ method in fuel cell studies, because it is the fastest and most cost-effective method for quick selection of electrode materials. The CCME composition conditions are investigated by design of experiment (DOE) proceeding which is performed with the response surface method (RSM) using the central composite design (CCD). The CCME is prepared with a Nafion 117 membrane and gas diffusion layer (GDL) having an active area of 0.785 cm2. The half-cell test results show that electrode with 0.50 mg cm−2 Pt loading, 28.78 wt% Pt% and 11.00 wt% Nafion in CL which predicted by mathematical model in the RSM, exhibits promoted behavior in ORR. The CCME with the predicted parameters shows the highest performance of 29.63 mW cm−2, which is confirmed experimentally.

Oil contamination is the most common pollution that is seriously harmful to ecological environments and human health. There is a huge demand to develop an effective and facile strategy for the separation of oily water. Here we report a universal self-assembly coating method via a one-step dopamine (DA) @γ-aminopropyl triethoxysilane (γ-APTS) Schiff base reaction for highly efficient separation of oil-water emulsions. The addition of γ-APTS not only accelerates the DA polymerization but also reduces the aggregation of polydopamine (PDA). Interestingly, the newly designed composite membrane possesses both high hydrophilicity and underwater superhydrophobicity. Under gravity-driven separation conditions, the membrane displays superior efficiency to separate oil-water emulsions with an ultrahigh water flux and splendid anti-oil-fouling ability. The coating layer also exhibits multiform robustness and stability owing to the formation of Schiff base covalent bonding. Importantly, the coated membrane has the ability to be used in a dry state without sacrificing its permeability ability. The desirable stability, simplicity of fabrication, and versatility of the DA@γ-APTS coating may open up new insights to molecularly design next-generation membranes with superior hydrophilicity and underwater superhydrophobic for oily water separation and purification.

The employment of copper-containing antibacterial agents for membrane modification can constrain undesirable bacterial adhesion and growth in an effective and economical way. However, copper ion may be leached out and cause further toxicity after applying those materials for membrane processes. Therefore, in this study, nano CuAl2O4 spinel was synthesized as a novel copper-containing material which was expected to have good antibacterial activity and simultaneously stabilize copper ions by its intrinsic structure. The obtained nano spinel was applied for membrane modification via both doping and coating methods. Results show that the addition of nano CuAl2O4 spinel during doping process can change polyvinylidene fluoride (PVDF) membrane properties (crystallization, tensile strength, porosity, pore size distribution, permeate flux and bovine serum albumin (BSA) rejection) obviously, but no obvious change was observed for the coated membrane except increased hydrophilicity and permeate flux. Most importantly, the amount of bacteria attachment was found to reduce significantly (˜68%) on the membrane coated with nano spinel, which indicates the successful application of nano CuAl2O4 spinel as a novel antibacterial agent for membrane modification without extra concern of copper toxicity.

Good oxygen permeability and stability of oxygen transport membrane are highly necessary for practical applications. Herein, through different theories, the oxygen transport limitation step through the Ruddlesden-Popper (Pr0.9La0.1)1.9Ni0.74Cu0.21Ga0.05O4+δ ((PL)1.9NCG) membrane was demonstrated firstly, which suggest surface modification can be an effective approach to improve the oxygen separation performance. After coating, various influences of different side surface modification on permeability and phase stability were observed. The sweep-side coated membrane exhibits largely enhanced permeation fluxes than feed-side coated membrane, and the feed-side coated membrane shows better phase stability under the same conditions (these results reveal that the sweep side is the permeability limitation side and the feed is the phase stability limitation side). The both side coated membrane combines abovementioned advantages which shows 57% enhanced and stable oxygen permeation flux at 800 °C. The observed various modification effects on the permeation performance are discussed based on the surface exchange properties and the mechanism of the oxygen transporting membrane in detail.

This work shows how to manufacture completely coated membrane electrode assemblies (CC-MEAs) for PEM water electrolysis by only using a slot die. Platinum, Nafion®, and IrO2 dispersions are successively coated to the respective dried layer. For comparison reasons, MEAs with the same Iridium loading of 2.1 mg cm−2 and Platinum loading of 0.4 mg cm−2, assembled with a commercial membrane of the same 20 μm thickness, were produced via decal method. Differences in polarization curves are attributed to the lower high frequency resistance of CC-MEAs determined by impedance spectroscopy. The easy-to-scale CC-MEA method presented here offers the advantages of direct membrane deposition (DMD) without the challenge of homogenously coating a porous transport layer (PTL). Therefore, it allows a free choice of different PTLs – regardless if in sintered form or as expanded metal. The comparability between the produced CC-MEAs and published DMD results is shown by means of cross-sectional and electrochemical measurements.

Catechol functionalized comb-shaped poly(N-vinylpyrrolidone) (CA-PLL-PVP) copolymer could be easily coated on the surface of a microporous polypropylene membrane for microfiltration. The copolymer (CA-PLL-PVP) was synthesized in one-pot by grafting PVP with terminal carboxyl moiety (PVP-COOH) and caffeic acid to the e-polylysine (PLL) backbone via carbodiimide/N-hydroxysuccinimide activated coupling. The coating significantly enhanced the water wettability of polypropylene (PP) membrane with contact angles dropped from 110° to near 0°. Excellent antifouling performance was achieved in the microfiltration using bovine serum albumin (BSA) and sodium alginate (SA) as model foulants that ~65% relative flux could be maintained by the coated membrane while only 35% for the pristine PP membrane. With simple physical cleaning the fouled membrane, approximately 90% of flux recovery was achieved for the coated membrane. In contrast, only less than 10% flux recovery was observed for the pristine membrane after 3 sequential cycles of microfiltration. PVP securely coated on PP microporous membrane via the conjugated catechol not only significantly reduced the fouling caused by BSA-SA mixture microfiltration but also facilitated the foulants on fouled membrane to be easily removed to recover the declined flux.

Polymeric microsphere coating through electrospraying utilizing a polymer mixture of polyvinylidene fluoride (PVDF) and poly(dimethylsiloxane) (PDMS) is a facile method for fabricating a superhydrophobic surface. This study describes another simple approach for improving polymeric microsphere coating by adding hydrophobic aerogel particles to the polymeric solution for electrospraying. The deformation of microspheres, such as the occurrence of broken microspheres and polymeric strings, became apparent as the concentration of aerogel particles was increased. Consequently, while the pure microsphere-coated membrane showed a 156.7° contact angle, that of the 30% aerogel-assisted microsphere-coated membrane was 162.1°, with a water droplet easily rolling on it. In addition, the 30% aerogel-assisted microsphere-coated membrane exhibited a high and stable repellency during continuous contact with a relatively low surface tension solution of 3.5% NaCl containing 0.1 mM sodium dodecyl sulfate (SDS). As a result, the coated membrane demonstrated highly stable vapor permeability according to direct contact membrane distillation (DCMD) testing using 3.5% NaCl solution including 0.1 mM SDS.

Oxygen enriched air (OEA) is widely applied in various areas such as chemical and medical applications. Currently, cryogenic distillation and pressure swing adsorption are the two common technologies that being commercially used for i the production of OEA. However, these two techniques are not economically favorable due to required intensive energy and large built-up area. With the advancement of membrane technology in separation process, it garners the interest from both industrial and academic to explore the feasibility of membrane in gas separation. In this study, polysulfone (PSF) hollow fiber membranes with poly(ether block amide) (PEBAX) coating were used for the separation of O2/N2 gas. The hollow fiber membranes used in this work were fabricated by phase inversion spinning process using PSF pellet, along with N,N-dimetyhlacetamide (DMAc) and ethanol (EtOH) as solvent and co-solvent, whereas tetrahydrofuran (THF) as additive. The fabricated membrane exhibited dense structure in the inner layer whereas finger like layer at the outer surface. The formation of this structure was attributed by rapid phase inversion of the solution arose from strong solvent used. The EDX surface mapping analysis confirmed the formation of PEBAX coating on the membrane surface. Gas permeation study in this work illustrated that the pristine PSF membrane exhibited better gas separation performance relative to the PEBAX coated membrane with 20% higher in terms of permeance. The results obtained from this work suggested that the PEBAX coating enhanced the membrane surface but not certain to improve the gas separation performance. Further study on the PEBAX materials for the membrane coating is essential to polish its potential in gas separation.

Many studies have been conducted on flow-electrode capacitive deionization (FCDI), by which the limited ion adsorption capacity per unit cell can be extended, and which can be applied to high-salinity water treatment. Especially, using low-cost ceramic filters as three-dimensional (3D) electrode structure for FCDI is possible, instead of stacking the unit cells for scale-up. However, using ceramic partition walls as spacer can affect water flow and ion transport due to their thickness and porosity. Furthermore, the integrated membrane-spacer-assembly (MSA) having a membrane-coated spacer is more suitable for 3D electrode structure than a separated MSA having a spacer sandwiched between membranes. Herein we investigated the effects of the thickness and porosity of plate-type porous ceramic spacers on the electrochemical properties of the cell and compared the electrochemical properties of separated MSA with those of integrated MSA. Spacer porosity was found to have a larger effect than spacer thickness. Integrated MSA had larger resistance and lower capacitance than separated MSA, leading to lower desalination performance. It was attributed to the change in physical properties of the spacer induced by coating and the difference in ion exchange capacity of the coated membrane itself.

In this work, the fabrication and characterization of a dual-purpose membrane is reported: (i) oil-water separation with high efficiency, and (ii) effective and rapid photocatalytic degradation of hazardous environmental pollutants. Nanoparticles of a rare-earth oxide, cerium (IV) oxide, synthesized by a simple co-precipitation technique, were spray-coated onto stainless steel membranes to obtain a uniform coating with superwetting characteristics. The as-synthesized cerium (IV) oxide nanoparticles and its spray-coated stainless steel membrane were characterized by advanced analytical techniques. X-ray diffraction, selected area electron diffraction, and electron microscopy results of the cerium oxide particles showed a high degree of crystallinity and uniform particle size of ∼50 nm. Elemental surface analysis using X-ray photoelectron spectroscopy showed the characteristic peaks for Ce4+, thereby confirming the presence of cerium oxide nanoparticles. Contact angle measurements showed the coated membranes to be superhydrophobic (∼150°) and superoleophilic (∼0°). When used in a simple laboratory setup, the membranes were able to separate oil and water with a high efficiency (∼99%). Furthermore, the coated membrane showed enhanced photocatalytic activity under UV light irradiation resulting in the rapid degradation of organic persistent pollutants like MB dye in water. To summarize, this work presents an innovative approach in the application of multifunctional membranes for effective water treatment.

Frequent oil spill accidents and industrial wastewater discharge result in severe health and ecological problems to human beings. Generally, industrial wastewater contains not only various kinds of oils, but also water-soluble dyes and heavy metal ions. Elimination of these contaminants in the process of oil/water separation is very important in industrial applications and still remains unsolved. Even though some membranes with underwater superoleophobicity have been extensively used toward oil-in-water emulsion separation, the bulk of them lack the capacity of removing the water-soluble pollutants from water during oil/water separation. Herein, a novel loess-coated polyvinylidene fluoride (PVDF) membrane was successfully fabricated through depositing the loess and sodium alginate suspension onto a PVDF membrane with a vacuum pump. The loess-coated PVDF membrane displayed extraordinary underwater superoleophobicity with oil contact angles larger than 150° and sliding angles smaller than 10° toward different oils, including crude oil with high viscosity. Besides, the loess-coated PVDF membrane can separate various oil-in-water emulsions with separation efficiencies up to 99.6% and flux as high as 910.4 L m−2 h−1 bar−1. Moreover, the coated membrane retained excellent separation performances even after 10 cycles. In addition, the coated membrane showed outstanding resistance to corrosive liquids, and could separate oil-in-water emulsions in corrosive solutions effectively. Furthermore, the as-prepared membrane displayed outstanding mechanical performance and flexibility. More importantly, the loess-coated PVDF membrane exhibited effective adsorption toward dyes and heavy metal ions. This cost-efficient, environmentally friendly and multifunctional loess-coated PVDF membrane not only allows natural loess resources to be used rationally, but also effectively solves the problems of water pollution.

We report on the employment of the electrochemical impedance spectroscopy (EIS) to characterize catalyst coated membrane (CCM) electrode assemblies (MEA) as a function of ionomer percentage versus relative humidity, in proton exchange membrane fuel cell (PEMFC). The catalyst layer was fabricated by spraying TKK catalyst containing Nafion ionomer directly onto Nafion membranes, sandwiched between two identical mesoporous layer coated gas diffusion layers (GDLMPL). Relative humidity was varied for the MEA's containing various Nafion contents (MEAM; M: Nafion wt. percentage per mass of Pt). The MEA20 had low charge transfer (RCT) and high ionic (Rion) resistances, while MEA60 showed high RCT and low Rion. Both generated inferior performances to MEA30, MEA40, and MEA50. These observations simply ruled out RCT or Rion to independently explain the fuel cell performance. However, the MEA30, MEA40, and MEA50 had a combination of low RCT and Rion, all producing power densities larger than 1.1 W cm−2. This indicates that both RCT and Rion would effectively contribute to the performance of the MEA's, where the maximum power density sharply dropped when sum of the normalized RCT and Rion (i.e. RT, total resistance) was ∼0.5 Ω or higher. It appears that the RT may be a reliable while simple parameter for assessing the ketjenblack-based TKK with Nafion as ionomer for PEMFC. Such diagnostic tool can be further evaluated and extended to other catalysts with different supports and ionomer compositions.