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Abstract: Graphene oxide (GO) dispersed polysulfone (PSf) mixed matrix membranes were prepared by wet phase inversion method. The morphology of membranes was studied using scanning electron microscope (SEM) images. The variation in hydrophilicity was studied by measuring surface wettability and water swelling experiments. The performance of membranes in terms of pure water flux and salt rejection was studied. SEM images depict enhanced macrovoids, while the contact angle data reveals that, GO incorporated membrane surface is moderately hydrophilic. Membranes exhibited improved salt rejection after GO doping. Membrane with 2000ppm GO loading has exhibited maximum of 72% Na2SO4 rejection at 4bar applied pressure. The salt rejection seems to depend on pH of the feed solution and it has been witnessed that the salt rejection showed an increasing trend with increase in the pH. [Copyright &y& Elsevier]

Abstract: Mixed matrix hollow fibers composed of multi-walled carbon nanotubes (MWCNTs) and polyetherimide (PEI) were fabricated. Pre-treatment of MWCNTs was carried out prior to the incorporation into the polymer matrix using a simple and feasible two stages approach that involved dry air oxidation and surfactant dispersion. The characterizations of the surface treated MWCNTs using TEM and Raman spectroscopy have evidenced the effectiveness of dry air oxidation in eliminating undesired amorphous carbon and metal catalyst while surfactant dispersion using Triton X100 has suppressed the agglomeration of MWCNTs. The resultant mixed matrix hollow fibers were applied for O2/N2 pure gas separation. Interestingly, it was found that removal of disordered amorphous carbons and metal particles has allowed the hollow structures to be more accessible for the fast and smooth transport of gas molecules, hence resulted in noticeable improvement in the gas separation properties. The composite hollow fibers embedded with the surface modified MWCNTs showed increase in permeability as much as 60% while maintaining the selectivity of the O2/N2 gas pair. This study highlights the necessity to establish an appropriate pre-treatment approach for MWCNTs in order to fully utilize the beneficial transport properties of this material in mixed matrix polymer nanocomposite for gas separation. [Copyright &y& Elsevier]

Abstract: Regenerated cellulose/montmorillonite (RC/MMT) nanocomposite films were successfully prepared in ionic liquid, 1-butyl-3-methylimidazolium chloride (BMIMCl) using solution casting method. The effect of MMT loading on the thermal, mechanical, gas permeability and water absorption properties of the nanocomposite films was investigated. X-ray diffraction analysis revealed a cellulose II crystalline structure and well dispersed MMT in RC/MMT nanocomposite films. Presence of MMT enhanced the thermal and thermal-oxidative stability and char yield of RC. The tensile strength and Young''s modulus of RC films improved by 12% and 40%, respectively with the addition of 6wt.% MMT. RC/MMT nanocomposite films exhibited improved gas barrier properties and water absorption resistance compared to RC. The results demonstrated that there is a possible interface interaction between cellulose and MMT which yielded better thermal and mechanical properties of the nanocomposite films as compared to pure cellulose. [Copyright &y& Elsevier]

Abstract: A more soluble polyaniline derivative, i.e. poly(o-anisidine), (POAn), was synthesized in-house for this study by using an ortho substituted aniline monomer. It was observed that the prepared dope solution was more homogeneous with less visible agglomerates as compared to previously prepared polyaniline (PAni) solution. Integrally skinned hollow fibre membranes were successfully prepared by dry-jet wet spinning from POAn with N-methyl-2-pyrrolidone as a solvent and a more volatile tetrahydrofuran as a co-solvent for gas separation. The spinning air-gap lengths were varied to promote the formation of the membrane skin layer. POAn membranes prepared at higher air gap were more orientated with packed structure and good gas separation characteristics. They showed selectivities of O2/N2, CO2/N2, H2/N2 and H2/CO2 of about 13, 89, 370 and 4.2, respectively with permeation rates of H2, CO2 and O2 about 10.4, 2.5 and 0.37×10−6 cm3 (STP)/cm2 scmHg, respectively. Presence of methoxy group in POAn showed substantial enhancement in gas permeation properties compared to previously developed PAni membranes. The H2/N2 and CO2/N2 selectivities were improved by 3 and 7 times, respectively as compared to PAni membranes. Development of hollow fibre membranes using polyaniline derivative with improved processability and excellent gas separation performance depicts their potential for industrial gas separation applications. [Copyright &y& Elsevier]

Abstract: Navigating novel biological routes to mitigate biofouling is of great worth inorder to allow sustainable performance of Membrane Bioreactors (MBRs) in wastewater treatment technology. Recently, it was confirmed that a number of natural compounds in plants have an anti-biofouling effect, reducing the formation of biofilm. This study addressed the feasibility of Piper betle extract (PBE) as anti-biofouling agent against the model organism Pseudomonas aeruginosa PAO1 and bacterial consortium. The anti-biofouling effects of PBE were evaluated via a microtiter plate assay; changes in the growth rate (μ) and EPS production. Scanning Electron Microscopy (SEM) was employed to qualitatively illustrate the biofilm formation. PBE revealed ≥80% reduction in biofilm formation, growth rate (87%) and reduced the EPS production. These results suggest that PBE could be a potential agent for the mitigation of membrane biofouling. However, the chemical stability, potential toxicity and consistent performance of PBE in the field will have to be further investigated for optimization of its use on a field scale. [Copyright &y& Elsevier]

Abstract: Since the breakthrough discovery made by Cadotte and his co-workers in the 1970s, thin-film composite (TFC) membrane prepared using interfacial polymerization (IP) technique has experienced significant progress in composite membrane development and emerged as one of the most advanced technologies in water and wastewater purification processes. Nowadays, the most promising technology to desalinate seawater is reverse osmosis (RO), which is driven by a pressure gradient across a semi-permeable membrane. This technology has drawn great attention mainly due to its relatively low energy usage during operation as well as easy of operation and maintenance compared to other conventional technologies such as thermal desalination. On the basis of the brief introduction on TFC membrane, this paper will highlight the recent developments of RO TFC membrane and its challenges in seawater desalination process with respect to fouling problem, boron rejection and chlorine attack. Future directions in SWRO membrane research are also discussed to further expand research and development related to seawater desalination process. [Copyright &y& Elsevier]

Abstract: Low molecular weight organic compounds were added to the spinning dope as phase inversion promoters and their effects on the structure of polyetherimide (PEI) hollow fibers as well as their performance as membrane contactor were investigated. Water, methanol, ethanol, glycerol and acetic acid were added individually to the solvent NMP to prepare a dope containing 15wt% PEI, 4wt% additive, 81wt% NMP and hollow fiber membranes were fabricated via wet spinning method. The solution containing water as the additive had the lowest thermodynamic stability and highest viscosity, which yielded hollow fiber with a thin skin layer of high porosity and a sublayer with sponge-like structure. The four other polymer solutions were more stable thermodynamically and less viscous. Fast solvent/coagulant exchange yielded thick skin layers of lower porosity and sublayers of finger-like macrovoids. Among all fabricated follow fibers, adding methanol resulted in the highest absorption flux, which was ascribed to its high porosity and low tortuosity. [Copyright &y& Elsevier]

Abstract: In this study, integrally skinned asymmetric hollow fiber membranes have been developed from emeraldine base form of polyaniline (PAni) for gas separation. High molecular weight PAni was synthesized in-house to provide the fresh supply of the polymer. The hollow fiber membranes were prepared using dry-jet wet spinning and the effects of air-gap distance on nascent fiber morphology, their gas permeation and mechanical properties were investigated. The spin-line stresses resulted in the molecular orientation of the polymer which had synergistic effect towards improving the gas performance of the PAni hollow fiber membranes. The induced molecular orientation also resulted in improvement in mechanical properties of the hollow fiber membrane. The use of volatile co-solvent, tetrahydrofuran (THF) assisted in the skin layer formation which showed a substantial improvement in the gas permeation performance of the hollow fiber as the time of evaporation was varied. Present PAni based hollow fibers showed a selectivity of 10.2 for O2/N2, 105.6 for H2/N2 and 7.9 for H2/CO2 with the H2 and O2 permeance of about 5.0 and 0.49×10−6 cm3 (STP)/cm2 scmHg, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Carbon nanotube based nanocomposite membranes have been fabricated through solution casting by embedding multi-walled carbon nanotubes (MWCNTs) within polyetherimide (PEI) polymer host matrix. In order to achieve fine dispersion of nanotubes and facilitate strong interfacial adhesion with the polymer matrix, the nanotubes were first treated with surfactants of different charges, namely anionic sodium dodecyl chloride, cationic cetyl trimethyl ammonium chloride and non-ionic Triton X100, prior to the dispersion in the PEI dope solution. Dispersion of MWCNTs in N-methyl-2-pyrrolidone solvent showed that the agglomeration and entanglement of the nanotubes were greatly reduced upon the addition of Triton X100. Scanning electron microscopy and atomic force microscopy examination has evidenced the compatibility of Triton X100 dispersed MWCNTs with the polymer matrix in which a promising dispersion and adhesion has been observed at the MWCNT-PEI interface. The increase in both thermal stability and mechanical strength of the resulting Triton X100 dispersed MWCNT/PEI nanocomposite indicated the improved interaction between MWCNTs and PEI. This study demonstrated the role of Triton X100 in facilitating the synergetic effects of MWCNTs and PEI where the resulting composite membrane is anticipated to have potential application in membrane based gas separation. [ABSTRACT FROM AUTHOR]

Abstract: This paper proposes a new multistage evacuated solar distillation system that was designed to increase the productivity and improve the efficiency of the simple solar still. The solar still works by virtue of the higher evaporation rate under vacuum conditions. A mathematical model for the system was developed and used to optimize the system design. Fluent software was used to simulate the simultaneous heat–mass processes of the still. NASTRAN software was used for the structural analysis. The system components were fabricated and the overall system was assembled. The preliminary results showed a significant improvement of the overall productivity. Indeed, the total productivity of the solar still is affected very much by changing the internal pressure. The productivity decreased as the pressure increased due to the lower evaporation rates at the higher pressure values. The influence of the characteristic height variation on the still''s estimated productivity was found to be very strong. As the height increases the productivity decreases significantly. [Copyright &y& Elsevier]

Abstract: Experimental and finite element analyses for hybrid and non-hybrid glass and carbon/epoxy composite tubes subjected to quasi static lateral indentation loading have been carried out. Four types of composite tubes, each of four layers and approximately 1.6mm wall thickness were fabricated by filament winding process. Tube length and inner diameter are, respectively, 350 and 100mm. Fiber orientation angles of +55°, −55°, +55°, −55° angle ply were considered for all the fabricated tubes. Hemispherical steel indenter of 50 mm diameter was used as an indenter. Load–displacement, circumferential and axial strain–displacement relations were plotted. Failure zone on the tubes surfaces was examined, drawn and discussed. On the other hand, finite element analysis for tubes of the same dimensions and materials was done. A comparison was done for the tested composite tubes between the finite element and the experimental results. Results obtained from this study show that carbon/epoxy tubes resists higher load with less deformation than the glass and hybrid glass-carbon tubes. Also, results show that the stacking sequence of hybrid composite tubes can be used to improve their strength and performance. For hybrid types tested, tubes with the external layer of carbon show higher strength than those of internal carbon fiber layers. It has been found that the load–displacement difference between the experimental and finite element results fell in the range of 1.2–18%. While the strain results fell in the range of 2–21%. [Copyright &y& Elsevier]

Abstract: Polymer electrolyte pore-filled membranes, for possible use in direct methanol fuel cells (DMFCs), have been prepared by radiochemical grafting of styrene into porous poly(vinylidene fluoride) (PVDF) films using simultaneous irradiation with an electron beam (EB) followed by a sulfonation reaction. The physico-chemical properties of the obtained polystyrene sulfonic acid pore-filled membranes are evaluated using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), ac impedance, and a methanol diffusion cell. The effects of variation of the grafting yield (Y%) on the ionic conductivity and the methanol permeability of the membranes are investigated. The ionic conductivity of the membranes increases with increase in Y% and exceeds that of the perfluorinated ionomer membrane, Nafion 117, at a grafting yield of 46%. The methanol permeability of 40 and 46% pore-filled membranes is lower than that of Nafion 117 by 53 and 71%, respectively. The performance characteristic factor suggests that these membranes are potential candidates for DMFC applications. [Copyright &y& Elsevier]

Abstract: Polystyrene sulfonic acid (PSSA) pore-filled poly(vinylidene fluoride) (PVDF) membranes have been prepared using simultaneous electron irradiation method. Porous PVDF films were grafted by pre-swelling in styrene solution and subsequent irradiation with an electron beam (EB) under nitrogen atmosphere and at ambient temperature. The grafted films i.e. polystyrene (PS) pore-filled PVDF were subsequently sulfonated with a diluted mixture of chlorosufonic acid. The effects of the reaction parameters on the content of PS grafted in the pores of PVDF films were investigated. The chemical and morphological properties of the membranes in comparison with their un-grafted and grafted counterparts were studied by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The transport properties of these membranes such as ionic conductivity and methanol permeability were evaluated and correlated with the content of PS grafted in the pores of the PVDF films. The PSSA pore-filled PVDF membranes with PS content in the pores of 40% and above showed superior performance characteristics compared to Nafion 117 membrane and therefore can be potential alternatives to improve the performance of direct methanol fuel cell (DMFC). [Copyright &y& Elsevier]

Local delivery of antibiotics utilising bone cement is a well-known approach for controlling postoperative infections related to implant. 1, 5 and 10 wt.% of clindamycin (Cli) was embedded into polymethylmethacrylate (PMMA)–based bone cement for inhibiting postsurgical infection. Clindamycin antibiotic drug was homogeneously embedded into the matrix of PMMA-based cement. The results revealed that the fabricated PMMA-based cement loaded with Cli presented a high compressive strength (~120 MPa). The PMMA-based cement loaded with low Cli presented better cytocompatibility compared with its counterpart loaded with high Cli owing to the better cell attachment on the surface of the cement with a lower release of Cli. The embedding of Cli into the cement improved its antibacterial performance, as implied by the considerably improved inhibition zone with amplifying Cli concentration. Taken together, PMMA-based cement loaded with 1–5 wt% Cli might be a promising antimicrobial bone cement to be employed in orthopaedic surgeries. [ABSTRACT FROM AUTHOR]

The effect of shear rate on the separation performance of reverse osmosis hollow fiber membrane is discussed. Experiments involving six different dope extrusion rates (DERs) (ranging 2.5–5 ml/min) are performed with the other process factors set at the optimum conditions determined by the Taguchi analysis. This will enable an assessment to be made on the relationship between the DER and the rejection rate. The regression method is used to analyse the experimental results and an empirical model has been developed. Simultaneously, it is found that there is a fairly strong correlation between extrusion shear rate and the rejection rate of the membranes, whereby as the shear rate increases, the rejection rate increases until a critical level of shear is achieved, beyond which reverse osmosis membrane performance deteriorates, suggesting that there exists an optimum shear rate which yields optimal membrane morphology for reverse osmosis hollow fiber membranes. [Copyright &y& Elsevier]

Water scarcity is a global issue that needs to be urgently addressed to alleviate its adverse impacts on social and economic development. Desalination has been touted as an attractive alternative that can sustainably provide freshwater, particularly when there is no better option to augment water supplies. Tremendous research innovations and evolutions have been made to improve desalination processes in various aspects. Hybridization of two of more desalination processes has been recognized as a promising approach to tackle the inherent disadvantages of conventional desalination processes in regards of energy consumption, water productivity and environmental impacts. While there remains a huge demand for thermal-based desalination particularly in the Middle East region, it is timely to provide a review to look into the progresses made in the hybridization of thermal-based desalination processes. The opportunities for further advancement in the hybridization of thermal-based desalination processes are also proposed. The driving forces for the hybridization of these processes include energy saving, increased freshwater production and improved flexibility in tapping renewable energy. The design and configurations, performances and optimizations have been made in the hybridizations of thermal-thermal or thermal-membrane desalination. Thermal-based hybrid desalination system represents the future trend of commercial scale desalination operations. • The hybridizations of thermal-based desalination processes are reviewed. • thermal-thermal and thermal-membrane based hybridizations demonstrate economic feasibilities and synergistic advantages. • Thermal-based hybrid system outperformed the standalone counterparts in various aspects. • Thermal-based hybrid system is the future trend of commercial scale desalination operations. [ABSTRACT FROM AUTHOR]

In this work, hybrid nanocomposites rice husk derived graphene (GRHA) and zeolitic imidazolate framework-8 (ZIF-8) were prepared for hydrogen adsorption. The main contribution of this study is the simplification of the synthesized GRHA/ZIF-8 hybrid nanocomposites. Besides that, the use of synthesized graphene from rice husk (RH) could help in overcoming environmental issue since disposal of RH is rather challenging. GRHA was obtained through calcining rice husk ash (RHA) at 900 °C for 2 h in a muffle furnace at atmospheric condition while the nanocomposite of GRHA/ZIF-8 was produced in free solvent condition using deionized water at room temperature for only 1 h. The N 2 adsorption-desorption indicated a type I isotherm. Interestingly, it was found that the BET specific surface area (BET SSA) of GRHA/ZIF-8 showed enhancement up to 3 times higher as compared to pristine GRHA with the addition of 0.2 g of GRHA. From the experimental data, the adsorption of H 2 by nanocomposite GRHA/ZIF-8 obeyed the pseudo-second order kinetic model and intraparticle diffusion model with R2 value up to 0.9890 and 0.8087 respectively at 12 bar. Moreover, the GRHA/ZIF-8 possessed highest hydrogen adsorption of 31.84 mmol/g at 12 bar. These impressive results are justified by the combination of ZIF-8's microporosity and GRHA's mesoporosity. • Rice husk derived graphene (GRHA) incorporated zeolitic imidazolate framework-8 (ZIF-8shows an enhanced hydrogen adsorption. • GRHA incorporated ZIF-8 (GRHA/ZIF-8) has a higher specific surface area as compared to pristine GRHA and ZIF-8. • KOH able to form porosity and increase the surface area of rice husk during the activation process. • Hydrogen adsorption capacity increases with time and specific surface area of the adsorbent. • The hydrogen adsorption at room temperature obey pseudo-second order model and intraparticle diffusion model. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) have been classified as promising membrane materials for ultimate and efficient water desalination attributed by its diversified structures, tunable chemical functionalities and pore structures that serve as additional water channels. MOF-integrated membranes have been successfully prepared and applied for desalination process via different membrane processes; namely reverse osmosis (RO), forward osmosis (FO), nanofiltration (NF) and membrane distillation (MD). While there are reviews on the applications of MOFs-based membranes for water purification, herein, we present a comprehensive review of recent progress of different types of MOFs-integrated membranes, with emphasis placed on water desalination. This review focuses on membrane requirements for different membrane processes, the development of suitable MOFs for water application, different approaches of designing MOFs-based membranes, prior of discussion on the recent progress of MOFs-integrated membranes for desalination using different types of membrane processes. Lastly, insights and perspectives are suggested in terms of future research directions and development challenges. • The tunable features making MOFs as promising materials for membrane fabrication/modification for desalination process. • Application of MOFs membranes is influenced by water stability, pore size, aperture window cage and dispersibility. • MOF-integrated membranes is the promising candidate to address the trade-off effects of membrane selectivity and permeability. • Different types of MOF-integrated membranes that can be applied in RO, NF, FO and MD for desalination process. • Some fundamental and technical aspects have to be addressed to realize the potential benefits of MOF-integrated membranes. [ABSTRACT FROM AUTHOR]

Introducing ZIF-8 into the PES-cSMM membranes played a pivotal role in the development of proton-conducting pathways and an effective methanol barrier. We employed dry-wet phase inversion techniques to fabricate PES-cSMM, finding that a 3 wt% cSMM content yielded optimal results. The resulting PES-cSMM exhibits impressive performance, with a 38% higher selectivity and a 95% greater methanol barrier compared to Nafion® 117. The imidazole-N-H linker in the terminal PES-cSMM/ZIF-8 promotes proton transport through a hydrogen bond chain, while the hydrophobic backbone acts as an effective methanol filter. As a result, PES-cSMM/ZIF-8 boasts a 13-fold higher water uptake than Nafion® 117 and achieves a 99% improvement in methanol sieving performance, a highly promising breakthrough for DMFC systems. Proton conductivity for the PES-cSMM/ZIF-8 immersion membrane reaches 19.5 × 10-3 Scm-1, comparable to Nafion® 117, which is 20.4 × 10-3 Scm-1. The structural flexibility of ZIF-8 within PES-cSMM facilitates efficient proton conduction, while the ZIF-8 cage acts as a robust methanol barrier. Computational analysis revealed covalent bonding within the PES-cSMM system. We characterized the chemical interactions in PES-cSMM/ZIF-8 using topology analysis, specifically the Atom in Molecules/Non-covalent analysis (AIM/NCI) technique. [Display omitted] • PES-cSMM made via dry-wet phase inversion; ZIF-8 added in-situ by growth immersion technique. • PES-cSMM/ZIF-8 shows promise in reducing methanol crossover, with good selectivity, stability, and proton conductivity for DMFC. • Proton transport occurs through non-covalent interactions with exposed sulfonic acid groups on the cSMMs within the membrane. • Computational findings suggest ZIF-8 interacts with methanol mainly via van der Waals forces. [ABSTRACT FROM AUTHOR]

• Review on new/modified IP techniques for defect-less TFN membrane fabrication. • Important characteristics of nanofillers to generate PA layer with high integrity. • Effects of nanomaterials on membrane physicochemical properties and performances. Thin film composite (TFC) reverse osmosis (RO) membrane has been dominating commercial desalination process for several decades since its inception in the 1970s. Despite the ability of generating high quality water at promising water permeability, the commercial TFC RO membrane is still susceptible to fouling and chlorine attack which lead to performance instability as a function of operation time. Over the past decade, the prowess of nanomaterials integration in overcoming the drawbacks of conventional TFC membrane has been proven by many research studies and this has led to the significant progress of thin film nanocomposite (TFN) membrane development. However, it remains a great challenge in integrating the inorganic nanomaterials with the polyamide (PA) selective layer of TFN membrane due to the incompatibility between organic and inorganic materials and the uneven distribution of nanomaterials. In view of this, this article intends to critically review various fabrication techniques that have been developed or modified to incorporate nanofillers within or atop PA layer for the development of TFN membranes. In addition, the essential characteristics of nanofillers in order to achieve good integration with PA layer as well as their impacts in improving membrane performance with respect to water flux, rejection, antifouling, antibacterial and chlorine stability are also reviewed. We hope this review article could provide insights to researchers in fabricating defect-free TFN RO membranes for enhanced water desalination. [ABSTRACT FROM AUTHOR]

• Current hydrophilic membrane materials used for oily wastewater treatment. • Membrane modification methods employed to minimize fouling. • Performance and properties review on the membrane for oily wastewater. • Hydrophilic and oleophobic membrane are favourable to enhance membrane performance. Oily wastewater has been recognised as the most dangerous form of environmental pollution since the pollutant comes from a variety of sources and may harm humans, animals, plants, as well as the environment. Membrane technology is one of the most effective methods to overcome this phenomenon owing to its high separation efficiency and relatively simple operational processes. However, the challenging part to obtain clean water from oily wastewater using this technology is the fabrication of membranes with hydrophilic and antifouling characteristics. Conventional polymeric membranes are susceptible to fouling, which is caused by the interaction of oil molecules with the surfaces of the membranes and can render the excellent rejection performance and water flux. Thus, the wettability and antifouling properties of this membrane play an important role in the management of this issue. This review provides insights into recent approaches of various types of materials and methods applied in oily wastewater treatment for hydrophilic membranes. The findings from various types of membranes and modification techniques have also been discussed. Furthermore, the methods used to reduce the fouling issues within the membrane for oil/water emulsion separation are elaborated. Finally, the challenges faced in the development of membranes for commercial applications are identified and the future outlook is presented. [ABSTRACT FROM AUTHOR]

Wound dressings based on nanofiber polymer scaffolds with good antimicrobial performance and skin reconstruction ability are promising options to thwart wound infection and accelerate wound healing. This paper reports on the synthesis via electrospinning of chitosan-alginate (CS-Alg) nanofiber dressings with various amounts of gentamicin (Gn; 0–10 wt%) as a drug delivery system. Smooth and continuous nanofibers with no obvious beads were created, with increases in the amount of Gn resulting in reduced fiber diameter. Antimicrobial tests showed the Gn-loaded nanofibers had good antibacterial performance as indicated by the inhibition of bacterial growth. CS-Alg nanofibers loaded with higher Gn concentrations exhibited greater antibacterial performance than those with lower Gn concentrations. In vitro cell culture studies demonstrated that CS-Alg wound dressings with 1–3% Gn improved L929 cell attachment and proliferation more than wound dressings with higher Gn concentrations. In vivo experiments revealed that Cs-Alg nanofibers loaded with 3% Gn significantly enhanced skin regeneration in a Balb/C mice model by stimulating the formation of a thicker dermis, increasing collagen deposition, and increasing the formation of new blood vessels and hair follicles. Collectively, Gn-loaded CS-Alg wound dressings can be considered a good candidate for drug delivery systems and skin regeneration applications. Image 1 • Chitosan-alginate/gentamicin wound dressing nanofibrous is fabricated via the electrospinning method. • CS-Alg/Gn fibrous exhibited greater antibacterial performance than those with lower Gn. • CS-Alg-(1–3)Gn mats showed higher cell attachment and proliferation than mats with higher Gn. • CS-Alg-3Gn wound dressing enhanced skin regeneration in a Balb/C mice model. • Antibacterial mechanism of the CS-Alg-Gn wound dressing nanofibrous is proposed. [ABSTRACT FROM AUTHOR]

Biofouling is a persistent and unmet challenge in reverse osmosis (RO) technology. The attachment of microorganisms on the membrane surface has severely deteriorated the performance of RO membranes hence significantly affected the overall productivity and energy consumption of the system. Different strategies have been established to mitigate the thorny issue in order to minimize the adverse impacts of biofouling. This contribution provides a comprehensive review on the contemporary strategies that are focused on RO membrane design and modification to address the biofouling issues. The strategies for the development of anti-biofouling RO membrane in terms of material characteristics and selections as well as the techniques established to render anti-biofouling properties are extensively discussed. The performance of RO membranes through approaches including coating, layer by layer, grafting immobilization and surface patterning are reviewed. Finally, this review is wrapped up with the technological issues and challenges as well as the future perspective of these strategies. • A review focuses on anti-biofouling modifications of RO membranes in recent 5 years. • Recent advances in materials development for antibiofouling modification of RO membrane • The advantages, limitation and performance of various antibiofouling modification approaches [ABSTRACT FROM AUTHOR]

The photoactivity of iron doped titania nanotubes (Fe-TNT) synthesized via facile hydrothermal technique was investigated using reactive black 5 (RB 5) as the model pollutant. The incorporation of iron (Fe) nanoparticles in titania nanotubes (TNT) structure was confirmed via x-ray diffraction while x-ray photoelectron spectroscopy analysis showed the presence of Fe3+ ions in the nanotube structure. Ultraviolet-visible spectrophotometer analysis confirmed the reduction in band gap energy, from 3.595 eV to 2.097 eV due to the interaction between Fe into TNT structure. The formation of tubular structure has also increased the specific surface area of the photocatalyst from 56.00 m2/g to between 246.23 m2/g to 142.01 m2/g for all Fe-TNT. Fe-TNT with Fe:Ti ratio of 1:3 demonstrated promising photodegradation efficiency of 90% within 120 min of visible light irradiation. The reduced band gap energy and improved visible light responsiveness imparted by incorporation of Fe nanoparticles into structure of TNT are the main factors for improved photocatalytic degradation. Unlabelled Image • Successful synthesis of hybrid Fe-doped TNT nanotubes via facile hydrothermal technique • Characterizations indicated successful incorporation of Fe particles into TNT lattice structure. • Dopant improved visible light sensitivity of TNT photocatalyst with degradation of more than 90% of model pollutant. • Developed a one-step for nanotube formation and metal doping [ABSTRACT FROM AUTHOR]

A ternary nanocomposite of Fe 3 O 4 @rGO@AgI was successfully synthesized by reflux method for photodegradation of phenol. The prepared nanocomposite was characterized for the physicochemical properties through XRD, FESEM, TEM, TGA, FTIR, and PL spectroscopy techniques. Fe 3 O 4 @rGO@AgI exhibited higher photocatalytic performance of 99% phenol degradation compared to 62, 75 and 78% using Fe 3 O 4 , Fe 3 O 4 @rGO and Fe 3 O 4 @AgI nanocomposites, respectively. The superior photocatalytic performance was mainly attributed to the rapid transportation of photogenerated electrons from GO nanosheets to AgI. The addition of H 2 O 2 has further enhanced the phenol degradation and was the optimized loading amount of 0.4 g/350 mL achieved the highest degradation efficiency. The findings revealed that basic conditions, initial phenol concentration and catalyst amounts have significant influence on the photocatalyst performance. The 81% recyclability after five continuous cycles implied the excellent stability of the photocatalyst for practical applications. Unlabelled Image • Fe 3 O 4 @GO@AgI was synthesized for phenol photodegradation. • Fe 3 O 4 @rGO@AgI showed improved photocatalytic activity of 99% phenol degradation. • Fe 3 O 4 @rGO@AgI exhibited excellent recyclability of 81% after five repeated cycles. • Effect of pollutant concentration, H 2 O 2 on Fe 3 O 4 @rGO@AgI also studied under batch mode. [ABSTRACT FROM AUTHOR]

• The NC-PtNPs/RGO was fabricated by novel one-step chemical reduction-assisted hydrothermal method. • NC-PtNPs were successfully formed and deposited on the basal plane and edge of RGO. • The NC-PtNPs/RGO catalysts exhibit excellent catalytic activity and durability towards MOR. Nanocluster-like Pt nanoparticles/reduced graphene oxide nanocomposite catalyst (NC-PtNPs/RGO) was synthesized through a novel one-step process of chemical reduction-assisted hydrothermal reaction by using formic acid as reducing agent. The crystallinity, morphology and composition of the NC-PtNPs/RGO catalysts were extensively characterized. The as-prepared NC-PtNPs/RGO catalysts exhibited higher electro-catalytic activity towards methanol oxidation than carbon black (CB)/PtNPs catalyst and could be ascribed to the high dispersion of NC-Pt NPs with large electrochemical surface area, release more exposure of active sites by NC-PtNPs structure and synergy effect of RGO. [ABSTRACT FROM AUTHOR]

• Mixed matrix composite membrane offers high separation performance. • PEBAX/Aminated partially reduced graphene oxide enhanced CO 2 selectivity. • A -prGO in active layer hindered the transportation of other gases than CO 2. In this study, the capability of a mixed matrix composite membrane (MMCM) fabricated using polyether block amide polymer PEBAX MH1657 from Arkema and in lab synthesized aminated partially reduced graphene oxide (A -prGO) nanofiller as a selective layer has been studied for gas separation. Moreover, the effects of nanofiller addition on membrane structure properties and performance were examined. The PEBAX/ A -prGO membrane was fabricated as a selective layer on top of a supporting substrate layer of polysulfone 1700. MMCM was prepared in five different loadings of A -prGO nanofiller (0, 0.05, 0.1, 0.2, 0.6 (w/w)%) of the used PEBAX amount. The synthesized nanofiller and fabricated MMCM were characterized using different characterization tests (XRD, FTIR, EDX, and SEM). The optimum separation of the membrane was found when the loading of A -prGO was 0.1%. The permeability of the membrane for CO 2 , N 2 and CH 4 gases were 47.5 Barrer for CO 2, 0.45 Barrer for N 2 & 2 Barrer for CH 4 while the selectivity of CO 2 /N 2 and CO 2 /CH 4 are 105.6 and 23.75, respectively. Surprisingly, the fabricated membrane performance found to be above the Robeson 2008 upper bound of permeability- selectivity relation for CO 2 /N 2 gases separation. [ABSTRACT FROM AUTHOR]

Recently, porous magnesium and its alloys are receiving great consideration as biocompatible and biodegradable scaffolds for bone tissue engineering application. However, they presented poor antibacterial performance and corrosion resistance which limited their clinical applications. In this study, Mg-Zn (MZ) scaffold containing different concentrations of tetracycline (MZ-xTC, x = 1, 5 and 10%) were fabricated by space holder technique to meet the desirable antibacterial activity and corrosion resistance properties. The MZ-TC contains total porosity of 63–65% with pore sizes in the range of 600–800 μm in order to accommodate bone cells. The MZ scaffold presented higher compressive strength and corrosion resistance compared to pure Mg scaffold. However, tetracycline incorporation has less significant effect on the mechanical and corrosion properties of the scaffolds. Moreover, MZ-xTC scaffolds drug release profiles show an initial immediate release which is followed by more stable release patterns. The bioactivity test reveals that the MZ-xTC scaffolds are capable of developing the formation of HA layers in simulated body fluid (SBF). Next, Staphylococcus aureus and Escherichia coli bacteria were utilized to assess the antimicrobial activity of the MZ-xTC scaffolds. The findings indicate that those scaffolds that incorporate a high level concentration of tetracycline are tougher against bacterial organization than MZ scaffolds. However, the MTT assay demonstrates that the MZ scaffolds containing 1 to 5% tetracycline are more effective to sustain cell viability, whereas MZ-10TC shows some toxicity. The alkaline phosphatase (ALP) activity of the MZ-(1-5)TC was considerably higher than that of MZ-10TC on the 3 and 7 days, implying higher osteoblastic differentiation. All the findings suggest that the MZ-xTC scaffolds containing 1 to 5% tetracycline is a promising candidate for bone tissue healing due to excellent antibacterial activity and biocompatibility. Unlabelled Image • Novel Mg-Zn scaffold loaded with tetracycline were prepared via space holder method. • MZ-TC scaffold possess compressive strength of 4.8 MPa with porosities of 65%. • The MZ-TC scaffolds showed desired drug release behavior during 20 h. • Antibacterial activity of MZ-TC scaffolds against S. aureus and E. coli were studied. • Cell viability and attachment of MZ and MZ-TC scaffolds were evaluated. [ABSTRACT FROM AUTHOR]

This study employed rotating bed plasma enhanced chemical vapor deposition technique to coat a thin polymeric film of polyaniline (PANI) onto titania nanotubes (TNT). The effect of plasma power on the growth of thin film polymer on the photocatalyst surface was investigated. Transmission electron microscope micrographs evidenced the formation of thin polymeric layers on TNT surface. Fourier-transform infrared spectra confirmed the presence of functional groups associated with PANI. The band gap of coated photocatalyst reduced from 3.23 eV to 2.54 eV, implying the photosensitivity of TNT-PANI in visible light range, while photoluminescence spectra showed that PANI coated TNT exhibited lower recombination rates. The photocatalytic performance of the resultant TNT-PANI titania were evaluated under both UV and visible light irradiation using reactive black 5 (RB 5) as the model pollutant. Unlike TNT which could only be activated under UV light, TNT-PANI coated using a plasma power of 50 W exhibited superior photoactivity under both ultraviolet (UV) and visible light irradiation. The incorporation of PANI enhanced UV light photodegradation performance, where reaction rate improved to 0.615 ppm min−1and three times higher compared to uncoated TNT. The best sample TNT-PANI 50 W exhibited promising photodegradation efficiency of 56.4% within 240 min of visible light irradiation. Unlabelled Image • Successful coating of polyaniline on surface of titania nanotubes via rotating bed-plasma enhanced chemical vapor deposition • Characterizations indicated successful growth of polyaniline thin film on TNT structure • PANI imparted visible light sensitivity, allowing photoactivation with visible light irradiation for degradation of model pollutant • Easy coating mechanism in controlled environment [ABSTRACT FROM AUTHOR]

The development of the clean synthesis of efficient bimetallic Pt-Pd alloy nanoparticles supported reduced graphene oxide (RGO) catalyst (RGO/Pt-Pd) through a facile, rapid, surfactant–free and novel one-pot process of chemical reduction-assisted hydrothermal reaction using formic acid as reducing agent have been introduced. The structural, elemental composition analysis and surface morphology of the as-prepared catalysts were extensively characterized by x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) and Raman spectroscopy, energy dispersive x-ray spectroscopy (EDX), high resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM), respectively. The electrochemical properties, catalytic activity and long-term stability performance of the RGO/Pt-Pd nanocomposite catalyst were employed by cyclic voltammogram and chronoamperometry. Furthermore, owing to the synergetic effects of Pt and Pd nanoparticles, the unique structure of Pt-Pd alloy nanoparticles and enhanced electron transfer by RGO, the as-synthesized RGO/Pt-Pd nanocomposite catalyst has demonstrated the enlarged electrochemical surface area (ECSA) (ECSA = 0.91 cm2), remarkably higher electro-catalytic activity (I f = 59.6 mA/cm2) and enhanced stability as compared to RGO/Pt (I f = 23.32 mA/cm2, ECSA = 0.18 cm2) and RGO/Pd (I f = 8.65 mA/cm2, ECSA = 0.11 cm2) nanocomposite catalysts toward methanol oxidation reaction (MOR). This superior catalytic activity of the as-prepared RGO/Pt-Pd nanocomposite catalyst with facile and simple preparation approach is promising a great opportunity for the development of direct methanol fuel cell. • RGO/Pt-Pd was produced by novel one-pot hydrothermal-assisted chemical reduction. • This one-pot hydrothermal-assisted chemical reduction method is effective, rapid and simple. • Formic acid was used as soft and non-metal reductant in the reaction process, without any surfactant or template. • Uniform Pt-Pd alloy nanoparticles supported on RGO formation were confirmed by HRTEM, XRD and XPS. • The as-synthesized nanocomposites exhibit superior catalytic activity and enhanced stability for methanol oxidation. [ABSTRACT FROM AUTHOR]

Novel polyphenylsulfone (PPSU)/nano tin oxide (SnO 2) mixed matrix hollow fiber membranes (HFMs) were fabricated by dry-wet spinning via phase separation method. In the current research, reported the contrast between neat PPSU membrane and nanocomposite membranes (PPSU/SnO 2), to determine the toxic reactive dyes namely, reactive black-5 (RB-5) and reactive orange-16 (RO-16) removal ability from the aqueous media. Scanning electron microscopy (SEM) was used to observe the HFMs cross-sectional morphological changes and surface roughness parameters of membranes were analyzed using atomic force microscopy (AFM). The surface wettability ability of HFMs was examined with a contact angle, water uptake, and porosity measurements. The cross-flow filter unit was engaged to quantify the water permeability, anti-fouling ability as well as the dye rejection ability of fabricated membranes. With increasing the SnO 2 NPs wt% in PPSU polymer matrix the membrane performance was enhanced continuously, it became evident that the incorporated SnO 2 NPs plays main role in membrane performance. Added, water-soluble poly (vinylpyrrolidone) (PVP) can also impact the pore morphology in membranes. At the end, PS-3 membrane exhibited lower contact angle (63.7 0), higher water uptake (74.8%), porosity (84.1%), pure water flux 362.9 L/m2 h, and high potential for dyes rejection application, of about >94% for RB-5, and >73% for RO-16 dye, respectively. From the preliminary results, it can be stated that the usage of SnO 2 NPs in membrane technology become effective towards wastewater treatment. Unlabelled Image • Novel PPSU/nano SnO 2 mixed hollow fiber membranes were fabricated by dry-wet spinning via phase separation process. • The cross-flow filter unit was engaged to check the permeability and rejection efficacy of the membranes. • The nanocomposite membranes showed better outcomes. • The PS-3 membrane displayed dyes rejection above 94% and 73% for RB-5 and RO-16 dyes, respectively. [ABSTRACT FROM AUTHOR]

Highlights • PMAPS incorporation onto TFC enhances its antifouling behaviour in oily separation. • PMAPS is super hydrophilic which greatly increases water flux. • Excessive loading of PMAPS creates non-uniform pores results in poor performance. • Hydrogen bonding formed from PMAPS and H 2 O prevents oil adherence onto membrane wall. Abstract The raising oil consumption in oil and gas industries has exacerbated the disposal of oil waste into various water streams. This phenomenon has called for treatments to prevent threats to the human and environment. With some great advantages such as lower membrane fouling rate, lower energy requirement and higher water recovery rate compared to the conventional pressure-driven membrane processes, forward osmosis (FO) has been recognized as a potential candidate for oily wastewater treatment. In this study, a poly[3-(N -2-methacryloylxyethyl- N,N -dimethyl)-ammonatopropanesulfonate] (PMAPS) incorporated thin film composite (TFC) membrane with excellent anti-fouling properties was fabricated for oily wastewater through forward osmosis process. PMAPS was blended with polyethersulfone (PES) dope solution and cast into PES support layer. Interfacial polymerization (IP) technique was applied to form a thin polyamide (PA) layer atop of the PES support layer. The PMAPS incorporated TFC membranes were characterized for their morphology and surface hydrophilicity. The resultant 1% PMAPS-TFC membrane exhibited high water flux of 15.79 ± 0.3 L/m2.h and oil flux of 12.54 ± 0.8 L/m2.h when tested in FO mode for oil removal from oily wastewater using 1000 ppm emulsified oily solution as feed solution and 2 M NaCl as draw solution. The oil rejection up to 99% was also obtained. Most significantly, PMAPS incorporated TFC membrane outperformed neat TFC membrane with lower fouling propensity for oily waste treatment. When treating 10000 ppm oil emulsion, PMAPS-TFC was able to achieve average flux recovery rate of 97% while neat TFC only able to achieve 70.8% of average flux recovery rate. [ABSTRACT FROM AUTHOR]

In the present study, porous magnesium-xzeolite (x= 0, 3, 5 and 7 wt.%) composite scaffolds containing different amounts of zeolite were synthesized through combination of powder metallurgy (PM) and space holder (SH) techniques. The findings demonstrated that incorporation of zeolite into Mg composite scaffolds leads to higher compressive strength and corrosion resistance than Mg scaffolds without Zeo. Moreover, the Mg/Zeo composite scaffold presented good bioactivity, high capability in MG63 cell attachment and viability whereas a smaller number of cells could attach to the Mg scaffold without Zeo. The antibacterial response of these Mg/Zeo-Ag composite scaffolds against Gram-positive Staphylococcus aureus (S. aureus) and Gram negative Escherichia coli (E. coli) indicates the positive role of silver-zeolite in suppressing the bacteria growth. The aforementioned tests indicated that the articulated magnesium composite scaffold containing 7 wt.% Zeo with suitable mechanical strength and excellent biological activity may be considered as a promising biomaterial for bone substitution. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • This work critically reviews the conventional and current methods for ammonia removal. • The capability of natural zeolite in adsorbing ammonia was also discussed. • The status of membrane technology in water treatment was discussed in detailed. • The technology of mixed matrix membrane for ammonia removal was thoroughly discussed. • The potential of natural zeolite adsorptive ceramic membrane for ammonia removal was proposed. Abstract The excessive amount of ammonia presents in water streams has led to a serious potable water scarceness worldwide. The application of conventional methods in removing ammonia suffers from many drawbacks. To this end, the shift towards adsorptive membrane application in eliminating ammonia has gained a great attention due to its outstanding performance attributable to the hybrid process, i.e., adsorption and filtration approaches, as a single step. Thus, this review critically discusses the current trend of ammonia removal means and the approach of fabricating adsorptive membrane. The future prospective on the utilisation of natural zeolite as adsorptive membrane is also conferred. [ABSTRACT FROM AUTHOR]

Highlights • Electro-spun polyethersulfone fibers possesses high surface area. • Nanoparticles (HMO) improved performance of ENMs for oil-in-water emulsion treatment. • Heat treatment effective in preventing delamination of the ENMs during UF processes. • ENMs showed high water flux with good rejection rate of 5000 and 10,000 ppm oily solution. • HMO-incorporated ENMs is efficient industrial oily effluents treatment. Abstract In this work, a new type of ultrafiltration (UF) electrospun nanofibrous membranes (ENMs) incorporating hydrous manganese dioxide (HMO) nanoparticles was fabricated with the objective of improving properties of polyethersulfone (PES)-based membrane for synthetic oily solution treatment. Two treatments were carried out to improve the mechanical property and hydrophilicity of the PES-based membrane without compromising its porosity and water permeance. The first treatment involved the use of mixed solvents – dimethylformamide and n-methyl-pyrrolidinone (DMF/NMP) in which NMP is a high vapor pressure component that could enhance the mechanical properties of the nanofibrous by improving solvent-induced fusion of inter-fiber junction points. The second treatment involved the incorporation of specific amount of HMO nanoparticles in PES dope solution to enhance membrane hydrophilicity. Heat treatment was also adopted as an effective approach to strengthen and prevent delamination of the nanofibrous mat during UF process. The HMO-incorporated ENMs exhibited an excellent oil rejection (97.98% and 94.04%) and a promising water flux recovery (89.29% and 71.10%) when used to treat a synthetic oily solution containing 5000 or 10,000 ppm oil, respectively. The best promising HMO-incorporated ENM exhibited much higher magnitude of water productivity (>7000 L/m2h) without sacrificing oil removal rate. Most importantly, this nanofillers-incorporated membrane showed significantly lower degree of flux decline as a result of improved surface resistance against oil fouling and is of potential for long-term operation with extended lifespan. The promising mechanical and anti-fouling properties of the ENMs is potentially applicable in the efficient industrial oily effluents treatment when challenged with oil-in-water emulsions. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Graphitic carbon nitride (GCN) photocatalyst was incorporated in nanofibers. • Photocatalytic nanofibers were electrospun on alumina hollow fiber membranes. • Cross-flow microfiltration demonstrated purification of oilfield produced water. • Hydrophilic, highly-porous nanofiber coating exhibited excellent fouling resistance. • Photodegradation ability of GCN offered cleaning performance of robust membranes. Abstract Cost-effective purification technology of oilfield produced water (OPW) is becoming a global challenge for future petroleum exploration and production industry. Energy-efficient operation of membrane separation is potentially promising. However, severe fouling problem of oil droplets demands new robust and fouling-resistant membranes with high permeability and rejection efficiency. Here, we propose a photocatalytic nanofiber-coated inorganic hollow fiber membrane suitable for OPW treatment. The membrane was fabricated by coating polyacrylonitrile (PAN) nanofiber incorporated with graphitic carbon nitride (GCN) photocatalyst on an alumina (Al 2 O 3) hollow fiber membrane. While the highly porous coating made of smooth hydrophilic nanofibers facilitated water permeation, the coating effectively captured oil droplets in its opening, resulting in a better rejection efficiency of oil contaminants. Its sparse mesh morphology prevented oil contaminants to form dense fouling film on the membrane surface and maintained high permeate flux even after 180 min filtration. The best permeate flux of 640 L·m−2·h−1 and oil rejection percentage of 99% were recorded for 180 min crossflow filtration of OPW at 2 bar along with the highest pure water flux of 816 L·m−2·h−1. The photocatalytic activity of GCN enabled the coating to degrade the captured oil contaminants under UV irradiation, demonstrating permeate flux of 577 L·m−2·h−1 and oil rejection of 97% after three cycles of 180 min filtration. The excellent fouling resistance and cleaning performances of the membrane are considerably beneficial for a long-term repeated filtration operation. This work will motivate researchers to develop nanofiber-coated hollow fiber membranes for future membrane separation technology. [ABSTRACT FROM AUTHOR]

• Fabrication of natural zeolite based ceramic membrane for ammonia removal. • Effect of sintering temperature on HFCM's properties and performance was studied. • Sintering temperature of 1050 °C has produced the best HFCM. • Ammonia removal using the fabricated HFCM gave nearly 90% rejection. • Synergism between adsorption and separation resulted to the high ammonia removal. The excessive presence of ammonia has led to serious potable water scarceness worldwide. This work aims to fabricate natural zeolite based hollow fibre ceramic membrane (HFCM) via phase inversion and sintering techniques for the ammonia removal in wastewater. The physical properties of the fabricated HFCM were investigated through morphologies, mechanical strength, dope suspension viscosity and pure water permeation also the performance test using synthetic wastewater. It was found that 5 cm, 15 mL/min and 1050 °C were the best fabrication conditions for the air – gap distance, bore fluid flow rate and sintering temperature, respectively. The membrane also revealed desired asymmetric structure, sufficient mechanical strength (50.92 MPa) and excellent pure water permeation flux (249.57 L/m2 h). Additionally, the ammonia removal gave an outstanding performance of 90% rejection. These findings show that natural zeolite based HFCM has a great potential to be developed as a single – step ammonia removal in wastewater. [ABSTRACT FROM AUTHOR]

Highlights • LSMM promoted surface migration of the O-g-C 3 N 4 to the topmost layer of the membrane. • 4 wt% is the optimum loading of LSMM that enhanced the properties of photocatalytic membrane. • Higher LSMM loading tend to form dense top layer with a smaller pore size on the membrane surface. • Incorporation of LSMM contribute to lower band gap energy about 2.75 eV. • Photocatalytic membrane achieved about 35.8% of phenol reduction. Abstract HydrophiLic surface modifying macromolecules (LSMM) modified polyethersulfone (PES) based photocatalytic membranes have been successfully prepared. This hybrid photocatalytic membrane applying oxygen-doped graphitic carbon nitride (g-C 3 N 4) as a photocatalyst was successfully fabricated via phase inversion technique in flat sheet form at ambient temperature. The potential of LSMM as membrane modifier was explored in detail under various loadings (1–5 wt%). The results show that the LSMM addition successfully increased the membrane hydrophilicity which may consequently prevent the membrane from comprehensive fouling. More appearance of g-C 3 N 4 on the membrane surface was observed by Scanning Electron Microscopy (SEM) and Atomic Force Microscope (AFM) analyses upon the LSMM addition. However, the trend tended to decline at the loading beyond 4 wt% of LSMM. At 4 wt% of LSMM, the PES/g-C 3 N 4 membrane successfully decreased phenol concentration up to 35.78% and rejected 14.73% of phenol. From the water flux result, the application of LSMM in water treatment application was hindered by the flux deterioration but a considerably high flux for an ultrafiltration membrane. The results indicate that the introduction of LSMM in the PES/g-C 3 N 4 hybrid photocatalytic membrane showed the great potential of LSMM as a membrane surface modifier for photocatalytic activities and membrane separation performance. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Reports of pharmaceuticals exist in surface water and drinking water around the world, indicate they are ineffectively remove from water and wastewater using conventional treatment technologies. The potential of adverse effect of these pharmaceuticals on public health and aquatic life, also their continuos accumulation have raised the development of water treatment technologies. Hybrid treatment processes like membrane filtration and advance oxidation processes (AOPs) are likely to give rise to efficient simultaneous degradation and separation mechanisms. Conventional membrane filtration techniques can remove the majority of contaminants, but the smallest, undegraded, and stabilized pharmaceutical wastes persist in the treated water. After some 20 years, researchers have recognized the important role of AOPs in the treatment of pharmaceutical wastewater because these technologies are capable of oxidizing recalcitrant, toxic, and non-biodigradable compounds into numerous by-products and finally, inert end-products via the intermediacy of hydroxyl and other radicals. Evidently, membranes are subjected to the fouling phenomenon by the contaminants in wastewater, hence resulting in a reduction of clean water flux and increase in energy demand. In such situations, these membrane hybrid AOPs exert a complementary effect in the elimination of membrane fouling, thus enhancing the performance of the membrane. Therefore, in this review, we describe the basic aspects of the removal and transformation of certain pharmaceuticals via membranes and AOPs. In addition, information and evidences on membrane hybrid AOPs in the field of pharmaceutical wastewater treatment is also presented. [ABSTRACT FROM AUTHOR]

A simple, scalable, novel polymer was synthesized by the aminolysis of poly(styrene-co-maleic anhydride) cumene terminated (PSMAC) using p- aminohippuric acid. The main objective was to perceive the effect of blend ratio of polysulfone (PSF) and poly[styrene-alt-(N-4-benzoylglycine-maleamic acid)] cumene terminated (PAH) on morphology and permeation properties of the membranes. The PSF/PAH blend membranes unveiled enriched hydrophilicity, porosity, zeta potential, water uptake and permeability owing to the existence of the hydrophilic PAH. However, the contact angle was not diminished over 20% of PAH ratio as there was an increase of hydrophobic alkyl group density. Differential scanning calorimetry (DSC) was employed for the determination of the glass transition temperature of the blends and the results revealed that the polymer blend is miscible in nature. Moreover, the M-3 membrane was screened for the heavy metal ion removal and achieved removal of 91.5% of Pb 2+ and 72.3% of Cd 2+ ions, respectively. The adsorption parameters indicated that the Langmuir isotherm model fits well for both Pb 2+ and Cd 2+ ions adsorption on M-3 membrane. The adsorption capacity attained from Langmuir isotherm model was 19.35 and 9.88 mg/g for Pb 2+ and Cd 2+ ions correspondingly. [ABSTRACT FROM AUTHOR]

Abstract In this study, thin film nanocomposite (TFN) membranes were fabricated by incorporating highly hydrophilic halloysite nanotubes (HNTs) and self-synthesized graphitic carbon nitride (g-C 3 N 4) nanoparticles into polysulfone-based substrate and interfacially polymerized polyamide top layer, respectively. The TFN membranes were evaluated for their performance in forward osmosis (FO) applications. The XRD, ATR-FTIR, FESEM and TEM results confirmed the successful synthesis of g-C 3 N 4 nanoparticles. The effects of nanomaterials incorporation were investigated in terms of membrane surface morphology, hydrophilicity and separation performance. When 0.05 wt/v% of g-C 3 N 4 was added to the polyamide layer, the membrane surface contact angle was significantly reduced from 68° in the control membrane (TFN0.0) to <10° in the TFN membrane (TFN0.05), leading to high water flux of 18.88 L/m2·h (approximately 270% higher than the TFN0.0 membrane). The results have proven the predominant effect of the polyamide layer modification compared to the support modification towards FO performance enhancement. The water flux decline for the TFN0.0 and TFN0.05 membranes after a prolonged time of 1200 min was only 12% for the TFN0.05 while TFN0.0 membrane experienced 24% reduction. In addition, fouling resistance of the membranes assessed by BSA revealed that the flux of TFN0.0 has reduced by 54% after 1200 min, meanwhile TFN0.05 recorded a reduction of approximately 30%. The findings confirmed the effectiveness of g-C 3 N 4 as a promising surface modifier for polyamide layer to simultaneously contribute to flux enhancement and increased anti-fouling properties. Highlights • HNT and g-C 3 N 4 were incorporated into the PSf substrate and PA layer of TFN FO membranes. • Superhydrophilic PA layer surface was attained with the incorporation of g-C 3 N 4. • Desalination performances of TFN FO membranes surpassed that of TFC and commercial membranes. • The anti-fouling property has been greatly enhanced. [ABSTRACT FROM AUTHOR]

In this work, green silica-based ceramic hollow fiber membranes (CHFMs) derived from rice husk ash waste were successfully prepared via phase inversion and sintering technique. Prior to the fabrication, rice husk waste was converted into amorphous and crystalline silica-based rice husk ash (ARHA and CRHA). The surface of CHFMs could be easily modified to become hydrophobic by grafting with a fluoroalkylsilane (FAS) agent. The CHFMs were characterized before and after grafting using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), measurement of contact angle and liquid entry pressure of water (LEPw), and three-point bending test. The pore size and the porosity of the membrane surface were also evaluated using mercury intrusion porosimetry (MIP). Lotus-leaf structure formed at the surface of HFMs by grafting, leading to a high contact angle of >150°. Direct contact membrane distillation (DCMD) performance of membrane after grafting was conducted for 200 h using the synthetic seawater of various NaCl concentrations at different feed temperatures. The experimental results show that the permeate flux decreased with the increasing feed concentration, whereas it was enhanced with the increasing feed temperature. A high water flux of 38.2 kg/m 2 h and salt rejection up to 99.9% were obtained by CHFM prepared from CRHA (CHFM/CRHA). [ABSTRACT FROM AUTHOR]

Adsorption is one of the most efficient ways to remove heavy metal from wastewater. In this study, the adsorptive removal of hexavalent chromium, Cr (VI) from aqueous solution was investigated using natural zeolite, clinoptilolite, in the form of hollow fibre ceramic membrane (HFCM). The HFCM sample was prepared using phase inversion-based extrusion technique and followed by sintering process at different sintering temperatures in the range of 900–1050 °C. The fabricated HFCM was characterised using scanning electron microscopy (SEM), contact angle, water permeability, and mechanical strength for all HFCMs sintered at different temperatures. The adsorption and filtration test of Cr (VI) were performed using an in-house water permeation set up with a dead-end cross-flow permeation test. An asymmetric structure with sponge- and finger-like structures across the cross-section of HFCM was observed using SEM. Based on the characterisation data, 1050 °C was chosen to be the best sintering temperature as the water permeability and mechanical strength of this HFCM were 29.14 L/m 2 ∙h and 50.92 MPa, respectively. The performance of the HFCM in adsorption/filtration was 44% of Cr (VI) removal at the Cr (VI) concentration of 40 mg/L and pH 4. In addition, the mathematical model was also performed in simulating the experimental data obtained from this study. All in all, the natural zeolite-based HFCM has a potential as a single-step Cr (VI) removal by membrane adsorption for the wastewater treatment. [ABSTRACT FROM AUTHOR]

• Increasing MPD and TMC concentrations enhance water vapor flux and membrane H 2 O/N 2 selectivity. • Increasing interfacial polymerization time controls the selectivity decline rate at high pressures. • Disregarding very low concentration of water vapor, it shows a great plasticizing impact on the gas permeance. • H 2 O-induced plasticization impact on nitrogen permeance is more intense than on water vapor. • Both the Henry and Langmuir models control the water adsorption while only the Henry controls N 2. Separation of moisture from gaseous mixtures, such as natural gas, humid air in food and goods storage warehouses or in sports halls and so on is of great importance. In this article, the separation of water from a wet gas stream is carried out by a TFC membrane made by interfacial polymerization on the sublayer of porous polyetherimide hollow fibers. Then the key-parameters affecting membrane efficiency is studied. The outcomes show that increasing the concentration of MPD has a substantial effect on enhancing the membrane water vapor flux. Moreover, it is disclose that increasing the concentration of TMC has the greatest effect on reducing nitrogen gas permeability and increasing the selectivity. Our findings reveals that disregarding the very low concentration of water vapor in the feed, shows a great impact on the permeance of each component compared to the pure state. Also, based on the modelling, it is obvious that for nitrogen gas in the entire pressure range, the adsorption mechanism is almost completely controlled by the Henry model, while the Langmuir adsorption mechanism is controlling for water vapor at low pressures, although at high pressures, the Henry mechanism has absolute superiority. Surprisingly, the H 2 O-induced plasticization impact on nitrogen permeance is more intense than on water vapor permeance. According to the modeling outputs, it is revealed that because D N2 is one to two order of magnitude lower than D H2O , water vapor permeance is much higher than that of nitrogen. [ABSTRACT FROM AUTHOR]

In this work, tailor-made graphene oxide (GO) incorporated thin film nanocomposite (TFN) membranes based on novel interfacial polymerization (IP) technique were presented. The embedment of GO nanosheets within ultrathin cross-linked polyamide (PA) layer was successfully achieved without forming particle agglomeration that could affect structural integrity. A total of five composite membranes with different GO loadings (0, 0.01, 0.02, 0.03 and 0.04 g/m 2 ) were fabricated and these membranes were characterized using TEM, FESEM, XPS, ATR-FTIR and contact angle goniometer to evaluate the impact of GO loading on the physicochemical properties of PA selective layer. It is found that with the presence of GO, the TFN membranes exhibited higher surface hydrophilicity due to increment in hydroxyl and carboxyl groups in PA layer, hence, improved the attraction between water molecules and membrane surface. Upon incorporation of 0.02 g/m 2 of GO, the resultant TFN membrane achieved 95.8% and 97.7% removal rate for Na 2 SO 4 and MgSO 4 , respectively along with 31.4% higher water flux than the membrane contained no GO. More importantly, this work demonstrated the broad applicability of novel IP technique in synthesizing TFN membranes with improved antifouling properties independent of the PA chemistry. [ABSTRACT FROM AUTHOR]

This paper presents a method for the separation of CO 2 /CH 4 and CO 2 /N 2 by the use of disk supported carbon membranes derived from polyimide. The supported polyimide membranes were carbonized under controlled gas flow (three different atmospheres: N 2 , Ar and He) at different carbonization temperatures from 600 to 900 °C. The carbon membrane fabricated at various carbonization temperatures and atmospheres, showed improvement in gas permeation performance. The gas permeability increased with the increase of carbonization temperature due to densification of the micropores in the carbon membranes, leading to enhanced gas permselectivity. All carbon membrane samples carbonized under three different atmospheres at 800 °C surpassed the polymeric CO 2 /CH 4 upper bound. Pure-gas permselectivity reached 98 for the carbon membrane carbonized at 800 °C under He gas flow, with CO 2 permeability of about 120 Barrer, becoming the most selective carbon membrane for CO 2 /CH 4 separation. [ABSTRACT FROM AUTHOR]

Thin film composite (TFC) reverse osmosis (RO) membrane, which has been widely applied for desalination, consists of an ultra-thin polyamide (PA) coating layer that supported on a porous support membrane. The main interest of this work is to perform facile acid modification on the polysulfone (PS) support of TFC and thin film nanocomposite (TFN) membranes. The PS support was acid treated with sulfuric acid (H 2 SO 4 ) at a concentration ranging from 1 to 2 M for 24–72 h. Response surface methodology (RSM) based on historical data design (HDD) was used to verify the optimum condition of support membrane with respect to NaCl rejection and water permeability. The highest water permeability was achieved at 1.13 L/m 2 .h.bar when nanoparticles loading of 0.03% was incorporated into the PA layer and PS support treated at 1.5 M H 2 SO 4 for 48 h. The NaCl rejection of all the synthesized membranes was found to be above 96%. [ABSTRACT FROM AUTHOR]

The application of low cost ceramic membrane from kaolin has attracted much interest due to its excellent mechanical stability, chemical and thermal resistivity and most importantly, because it is cost effective, in some cases, compared to polymeric membranes. The advantage of kaolin based ceramic membrane is its thermal properties that allow sintering at much lower temperature than alumina. Although many studies have been made on the application of kaolin based ceramic membranes, detailed discussions were scarcely made and the information on the fabrication of ceramic membrane from kaolin is very limited. This article is aimed to make a comprehensive review on ceramic membrane from kaolin for its fabrication methods and applications. An attempt is also made to show the future direction of the R and D on the kaolin based ceramic membrane. [ABSTRACT FROM AUTHOR]

The efficient removal of Endocrine Disruptive Chemicals (EDCs) namely oxybenzone and atrazine using polysulfone (PSf) composite membranes is reported in this article. A negatively charged hydrophilic mixed matrix membrane was prepared by using Polyaniline modified halloysite nanotubes (PANi-HNT) and polysulfone. The X-ray diffraction (XRD) and attenuated total reflectance infrared (ATR-IR) technique confirm the conversion of Halloysite nanotubes to Polyaniline modified halloysite nanotubes and their presence in membrane matrix. The microvoids observable in the SEM images depict the internal structure of the membrane. Further, increasing in the water uptake and decreasing in the contact angle with respect to increasing the concentration of Polyaniline modified halloysite nanotubes confirm the enhancement of the membrane hydrophilicity. This hydrophilicity increases for higher concentrations of PANi-HNT leads to a significant improvement of the water flux. The removal efficiency of prepared mixed matrix membranes was found to be 98% for oxybenzone and 50% for atrazine. The separation process was discussed in terms of adsorption coefficient, membrane charge and mean pore size. Considering the performances highlighted in this study, the proposed membranes appear usable for the removal of EDCs from contaminated solutions. [ABSTRACT FROM AUTHOR]