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Incorporating nanoparticles into polymer matrices for enhanced antimicrobial properties is particularly interesting. This study examines how the interlayer distribution of zinc oxide (ZnO) decorated with silver nanoparticles (AgNPs) within poly(methyl methacrylate) (PMMA) films impacts their antimicrobial activity. Various PMMA multilayer films were prepared, with the antimicrobial additive intentionally placed in the outer, core, bottom, or throughout all layers. Their efficacy was tested against gram‐negative (Escherichia coli) and gram‐positive (Staphylococcus aureus) bacteria. Results indicate that E. coli was the strain with the highest sensitivity to the system because it is a gram (−) bacterium, which could generate a lower resistance to AgNPs. On the other hand, S. aureus, being gram (+), presents a thicker lipid membrane, and peptidoglycan wall, which makes it difficult for AgNPs to enter. Films with uniform distribution throughout thickness exhibited the most sustained antimicrobial activity due to high antimicrobial concentration. This study demonstrated that the distribution of the AgNPs/ZnO system in different layers of a PMMA film influences its antimicrobial capacity. Finally, a mechanism for migrating silver ions released from the AgNPs/ZnO system in PMMA films is proposed, highlighting their interactions with bacterial cells and the subsequent antimicrobial effects. Highlights: Interlayer distribution influences antimicrobial activity.Outer placement leads to rapid silver ion release.Core distribution controls antimicrobial kinetics.Uniform distribution ensures sustained activity. [ABSTRACT FROM AUTHOR]

AbstractThe treatment of industrial wastewater is crucial for recovering water of high purity, especially considering its significance in mitigating environmental pollution and ensuring sustainable water resources. This study focuses on the purification of industrial wastewater, emphasizing the separation of tetrahydrofuran (THF) from aqueous solutions using membrane-based techniques. Composite membranes incorporating magnetic nanomaterial (magnetite) within a sodium alginate matrix were synthesized and evaluated for their effectiveness in purifying water from THF mixtures. Both Pervaporation (PV) and Vapor Permeation (VP) processes were employed, with thorough analysis conducted on the impact of magnetite content on permeate purity. The study identified optimal magnetite content for industrial wastewater treatment and developed a new membrane composition based on these findings. The VP process’s performance was evaluated by determining the permeation flux and separation factor. The highest separation factor of 460 was obtained for an 80% wt. THF-water solution in the VP process. Using these findings, the optimal magnetite content for industrial wastewater treatment was identified, and a new membrane composition was developed. The activation energies for the permeation of THF through the NaAlg-Fe20 membrane were found to be 10.50 kcal/mol and 7 kcal/mol for the VP and PV processes, respectively. [ABSTRACT FROM AUTHOR]

Efficient incorporation of macrocycles in polymeric membranes can impart the overall matrix with new properties for a range of cutting‐edge applications. Here, we introduce a Supramolecular Interfacial Assembly (SIA) method for the fabrication of polymeric membranes featuring embedded macrocycles. Through harnessing the quasi‐liquid nature of the concentrated polymer solution, SIA orchestrates the homogeneous spreading of macrocycles in an aqueous layer on its surface, leading to the creation of an interface between “water/water” phases, subsequently forming a cross‐linked membrane driven by supramolecular electrostatic interactions. Remarkably, compared to the traditional interfacial polymerization, SIA adheres to a “green” paradigm without the need for organic solvents. The resultant composite membrane exhibits superior performance in organic solvent nanofiltration (OSN), owing to the precise molecular sieving property provided by the macrocycles with well‐defined permanent cavities. This fabrication method holds great promise for the innovative design and production of composite membranes that seamlessly integrates macrocycles with conventional polymers, which can greatly impact the design and preparation of advanced membrane materials in the future. [ABSTRACT FROM AUTHOR]

Gas separation is the process of separating primary gaseous components from the composition of air. The separated primary gaseous components are essential for many industrial purposes such as chemical, medical, aeronautical, food processing industries. Oxygen enriched air plays a crucial role in the fuel combustion process and medical applications. Membrane technology emerges in the field of gas separation due to its inherent multidirectional characteristics. The multilayer composite polymeric membrane has been developed using electrospun web, nonwoven substrate and casting polymer solution to improve the permeability and selectivity of oxygen gas molecule from the gas mixture. This membrane also consists of polyethylene glycol (PEG) and SiO2 nanoparticles which are used to improve the permeability and selectivity of oxygen molecules. Box- Behnken design has been wielded for the membrane construction by three independent variables such as volume of electrospinning solution (mL), Casting Solution (mL) and PEG concentration (%). Oxygen separation is carried out using the gas separation unit and it is constructed based on the principle of air separation. To analyze the performance of the developed membrane, the purity of oxygen from the composite membrane is estimated by a GC-MS. Mass per unit area and thickness of all membrane samples has been tested. From the results, the electrospun web thickness and casting solution concentration directly influence the oxygen purity and air separation rate. SiO2 nanoparticles are added to the casting solution and the electrospun web. The presence of SiO2 in the top and bottom layer of the membrane is used to attract the O2 molecules. Maximum oxygen purity was obtained from the membrane which has an electrospun web with 6mL and 30% casting solution with 2% PEG. From this flat sheet composite membrane, the purity range of oxygen is 42.2% with moderate permeability flux. [ABSTRACT FROM AUTHOR]

AbstractThe membrane, a core element in pervaporation technology, is of utmost importance for its advancement. Membrane modification is one of the most effective means of achieving an efficient membrane, which is crucial for the progress of this technology. High selectivity and flux can be achieved by modifying the membrane or membrane polymer by changing properties such as the surface energy, surface roughness, arrangement of polymer chains, and polymer network. Hence, recent publications on various methods for modifying polymeric membranes in the context of pervaporation applications are meticulously summarized and categorized, and aging and fouling factors have been mentioned in this review. This evaluation provided a thorough summary of the benefits and drawbacks of each method. Among the numerous techniques, mixing, crosslinking, and surface modification are commonly employed to modify polymeric membranes specifically tailored for pervaporation processes. [ABSTRACT FROM AUTHOR]

In this work, we design an efficient and cost-effective porous membrane composed by polymeric blend that supports different photocatalytic materials. The thin (300 μm) porous photocatalytic membrane has a tubular shape and was flexible for easy handle in the reactor. The membrane is composed of a polymeric blend based on cellulose acetate, crystalline nanocellulose and polyvinyl alcohol, obtained by the phase inversion method, using cold water as non-solvent. Bismuthates (KBiO 3 , NaBiO 3) and aluminates (ZnAl 2 O 4 and Cu 0·9 Zn 0·1 Al 2 O 4) powders were synthesized by diverse methodologies and were embedded into polymeric matrix. The hydrogen evolution performance of photocatalyst powders and photocatalytic composite membranes, under UV light irradiation during 180 min, were compared. The best result of hydrogen evolution was obtained by Cu 0·9 Zn 0·1 Al 2 O 4 powders reaching 117.74 μmolg−1h−1 and the M−CuZn membrane reaching 90.07 μmolg−1h−1. The obtained results show the high potential of these polymeric membranes as a green alternative support for photocatalysts for hydrogen evolution. [Display omitted] • Cost-effective membrane composed by polymeric matrix (CA/CNC/PVA) such as Support for different photocatalysts. • Tubular shape, porous, flexibility and hydrophilicity character and easy of handle are shown in all membranes. • M − CuZn membrane reached 90.07 μmolg-1h-1 of hydrogen evolution performance. • The reuse of M − CuZn proved stability after three cycles of use with a decrease only 28% of initial performance. • Not sacrificial reagents were used in this work. [ABSTRACT FROM AUTHOR]

Contact angle measurement by sessile drop (SD) and captive bubble (CB) method is calculated by the four software, i.e. 'Angle Tool' plugin, Drop Snake (DS) plugin, and LB-ADSA plugin of the ImageJ®; and the Ossila® with their advantages and disadvantages. In this study, the ease of use and precision were tested by standard deviation calculation for different hydrophilic membranes. Angle Tool plugin, and DS plugin of ImageJ®; and the Ossila software gave high standard deviations due to rough cut membranes edges giving background shadows misleading the software algorithm. LB-ADSA plugin of the ImageJ® had both advantages of manual drop edge selection and algorithmic calculation of contact angle giving the lowest standard deviation. Therefore, we found that the LB-ADSA plugin of ImageJ® is precise for hydrophilic membranes by both SD and CB methods. [ABSTRACT FROM AUTHOR]

• Novel in vitro methods are necessary to substitute costly, slow, and highly complex in vivo models to evaluate ophthalmic formulations. • The efficacy of topical ophthalmic drug products depends directly on formulation residence time in the eye, which must be sufficient for the drug to penetrate the cornea to reach the site of action at therapeutic levels. • A new in vitro alternative method that mimics the in vivo dynamic barriers of the eye by using a dynamic tear flow system and a synthetic barrier to simulate the cornea is presented. • The OphtalMimic is a promising tool for comparing the performance of ophthalmic formulations regarding their residence time. The necessity of animal-free performance tests for novel ophthalmic formulation screening is challenging. For this, we developed and validated a new device to simulate the dynamics and physical–chemical barriers of the eye for in vitro performance tests of topic ophthalmic formulations. The OphthalMimic is a 3D-printed device with an artificial lacrimal flow, a cul-de-sac area, a support base, and a simulated cornea comprised of a polymeric membrane containing poly-vinyl alcohol 10 % (w/v), gelatin 2.5 % (w/v), and different proportions of mucin and poloxamer, i.e., 1:1 (M1), 1:2 (M2), and 2:1 (M3) w/v, respectively. The support base is designed to move between 0° and 50° to replicate the movement of an eyelid. We challenged the model by testing the residence performance of poloxamer®407 16 % and poloxamer®407 16 % + chitosan 1 % (PLX16CS10) gels containing fluconazole. The test was conducted with a simulated tear flow of 1.0 mL.min−1 for 5 min. The OphthalMimic successfully distinguished PLX16 and PLX16C10 formulations based on their fluconazole drainage (M1: 65 ± 14 % and 27 ± 10 %; M2: 58 ± 6 % and 38 ± 9 %; M3: 56 ± 5 % and 38 ± 18 %). In conclusion, the OphthalMimic is a promising tool for comparing the animal-free performance of ophthalmic formulations. [ABSTRACT FROM AUTHOR]

The OphthalMimic is a 3D-printed device that simulates human ocular conditions with artificial lacrimal flow, cul-de-sac area, moving eyelid, and a surface to interact with ophthalmic formulations. All tests with such a device have used a continuous artificial tear flow rate of 1 mL/min for 5 min. Here, we implemented protocol variations regarding the application time and simulated tear flow to increase the test's discrimination and achieve reliable performance results. The new protocols incorporated the previously evaluated 0.2% fluconazole formulations containing or not chitosan as a mucoadhesive component (PLX16CS10 and PLX16, respectively) and novel moxifloxacin 5% formulations, either in a conventional formulation and a microemulsion (CONTROL and NEMOX, respectively). The flow rate was reduced by 50%, and a pre-flow application period was also included to allow formulation interaction with the membrane. The OphthalMimic model was used with both polymeric and hydrogel-based hybrid membranes, including a simulated eyelid. Lowering the flow made it feasible to prolong the testing duration, enhancing device discrimination potential. The hydrogel membrane was adequate for testing nanostructure formulations. The OphthalMimic device demonstrated once again to be a versatile method for evaluating the performance of ophthalmic drug formulations with the potential of reducing the use of animals for experimentation. [ABSTRACT FROM AUTHOR]

In this study, the transport performance of acetaminophen (paracetamol), which is most commonly prescribed and used for humans and animals and whose wastes are known to have toxic effects on the environment and some living organisms, was investigated using zinc oxide (ZnO)-reinforced polymer membranes. In this study, nanoparticle-containing polymer membranes were prepared from cellulose triacetate in dichloromethane and ZnO nanoparticles were synthesized to impart adsorption properties to the membrane in a single step, enabling adsorption and filtration to improve the removal of low molecular weight micropollutants that are poorly retained by conventional polymer membranes and by enabling re-release. Our membrane was prepared by phase inversion method by doping with cellulose triacetate (CTA) solution. Parameters such as carrier concentration, mixing rate, transport time, acceptor and feed phase concentrations were studied to determine the optimal conditions for the transport experiments of paracetamol (PARA). The presence of acid in the acceptor phase converted the hydrophilic part of paracetamol, which allowed the transport of PARA. The calculated flux values for different PARA concentrations ranged from (0.64) × 10−8 to (1.8) × 10−8 mol/(cm2s). Under optimal conditions, a transport efficiency of 84% was obtained for PARA with a CTA/ZnO polymer membrane. The obtained membranes can be used in wastewater treatment, recovery of pharmacological products from pharmaceutical industry waste, re-evaluation of hospital waste, etc. [ABSTRACT FROM AUTHOR]

The novel mixed-matrix membranes that are designed to simultaneously enhance gas permeability, selectivity and filler–polymer compatibility are highly sought for industrial deployment of membrane technology for large-scale CO2 capture. Carbon capture performance of polymeric membranes is significantly improved by doping mesoporous zeolitic imidazolate framework (ZIF-L) nanoflakes into polymer matrix. ZIF-L is prepared via cold-synthesis method and is incorporated in varied concentrations into polyethersulfone (PES) matrix to improve CO2 permeability and CO2/N2 selectivity of resultant membranes. Morphological and structural characteristics of synthesized ZIF-L nanoparticles are characterized by SEM and XRD, respectively. Flat-sheet membranes prepared through phase inversion method are characterized to evaluating their structural, crystalline, morphological and thermal properties by FTIR, XRD, SEM and TGA techniques. Characterizations indicated homogeneous dispersal of nanofillers along strong interactions between ZIF-L to polymer chains which enhanced the carbon capture efficiency of membranes and measured as CO2 permeability and CO2/N2 selectivity by gas permeation test under different feed-side upstream pressures. Both filler concentration and feed pressure led to enhanced permeation through membranes in comparison with pristine PES membrane, and CO2 permeability increased from 3.7 to 24.9 Barrer for 3% ZIF-L nanoflakes doping while CO2/N2 selectivity is increased from 2.2 to 30.6 for 2% filler loading at 1.5 bar pressure. Raising feed pressure from 1.5 to 6 bar is resulted into CO2 permeability increment from 24.9 to 27.2 Barrer for 3% filler loading. Therefore, these designed membranes have efficacy for permeability for CO2 and N2 in industrial applications and environmental solutions. [ABSTRACT FROM AUTHOR]

Magnesium (Mg) is a widely used and attractive metal, known for its unique physical and chemical properties, and it has been employed in the manufacture of many practical materials. Layered Double Hydroxides (LDHs), particularly Mg-based LDHs, rank among the most prevalent two-dimensional materials utilized in separation processes, which include adsorption, extraction, and membrane technology. The high popularity of Mg-based LDHs in separation applications can be attributed to their properties, such as excellent hydrophilicity, high surface area, ion exchangeability, and adjustable interlayer space. Currently, polymer membranes play a pivotal role in semi-industrial and industrial separation processes. Consequently, the development of polymer membranes and the mitigation of their limitations have emerged as compelling topics for researchers. Several methods exist to enhance the separation performance and anti-fouling properties of polymer membranes. Among these, incorporating additives into the membrane polymer matrix stands out as a cost-effective, straightforward, readily available, and efficient approach. The use of Mg-based LDHs, either in combination with other materials or as a standalone additive in the polymer membrane matrix, represents a promising strategy to bolster the separation and anti-fouling efficacy of flat sheet mixed matrix polymer membranes. This review highlights Mg-based LDHs as high-potential additives designed to refine flat sheet mixed matrix polymer membranes for applications in wastewater treatment and brackish water desalination.

Abstract A new drug delivery system using an asymmetric polyethersulfone (PES) membrane modified by SBA-15 and glutamine-modified SBA-15 (SBA-Q) was prepared in this study by the aim of azithromycin delivery enhancement in both in vitro and ex vivo experiments. The research focused on optimizing membrane performance by adjusting critical parameters including drug concentration, membrane thickness, modifier percentage, polymer percentage, and pore maker percentage. To characterize the fabricated membranes, various techniques were employed, including scanning electron microscopy, water contact angle, and tensile strength assessments. Following optimization, membrane composition of 17% PES, 2% polyvinylpyrrolidone, 1% SBA-15, and 0.5% SBA-Q emerged as the most effective. The optimized membranes demonstrated a substantial increase in drug release (906 mg/L) compared to the unmodified membrane (440 mg/L). The unique membrane structure, with a dense top layer facilitating sustained drug release and a porous sub-layer acting as a drug reservoir, contributed to this improvement. Biocompatibility assessments, antibacterial activity analysis, blood compatibility tests, and post-diffusion tissue integrity evaluations confirmed the promising biocompatibility of the optimized membranes. Moreover, long-term performance evaluations involving ten repeated usages underscored the reusability of the optimized membrane, highlighting its potential for sustained and reliable drug delivery applications.

This article provides a comprehensive review of the state-of-the-art technology of polymeric mixed-matrix membranes for CO2/CH4 separation that can be applied in medium, small, and domestic biogas systems operating at low pressures (0.2-6 kPa). Critical data from the latest publications of CO2/CH4 separation membranes were analyzed, considering the ratio of CO2/CH4 permeabilities, the CO2 selectivity, the operating pressures at which the membranes were tested, the chemistry of the polymers studied and their gas separation mechanisms. And the different nanomaterials as fillers. The intrinsic microporous polymers (PIMs) were identified as potential candidates for biomethane purification due to their high permeability and selectivity, which are compatible with operation pressures below 1 bar, and as low as 0.2 bar. This scenario contrasts with other polymers that require pressures above 1 bar for operation, with some reaching 20 bar. Furthermore, the combination of PIM with GO in MMMs was found to not influence the permeability significantly, but to contribute to the membrane stability over time, by preventing the structural collapse of the membrane caused by aging. The systematic analysis here presented is a valuable resource for defining the future technological development of CO[sub 2]/CH[sub 4] separation membranes for biogas biorefining. [ABSTRACT FROM AUTHOR]

• Mg-based LDHs are the most prominent and common LDHs, with attractive features such as hydrophilicity, porous structure, high surface area, adjustable interlayer space, and ion exchange capability. • These properties make Mg-based LDHs highly applicable in membrane separation processes. • Polymeric membranes, commonly used in separation processes, have limitations such as high fouling, light permeability, and weakness in separation. • The use of effectual additives like LDHs, especially Mg-based LDHs, is a promising method to overcome these limitations. • Extraordinary properties of Mg-based LDHs and their good processability have created strategies to improve the performance of flat sheet mixed matrix polymer membranes in wastewater treatment and brackish water desalination processes. Magnesium (Mg) is a widely used and attractive metal, known for its unique physical and chemical properties, and it has been employed in the manufacture of many practical materials. Layered Double Hydroxides (LDHs), particularly Mg-based LDHs, rank among the most prevalent two-dimensional materials utilized in separation processes, which include adsorption, extraction, and membrane technology. The high popularity of Mg-based LDHs in separation applications can be attributed to their properties, such as excellent hydrophilicity, high surface area, ion exchangeability, and adjustable interlayer space. Currently, polymer membranes play a pivotal role in semi-industrial and industrial separation processes. Consequently, the development of polymer membranes and the mitigation of their limitations have emerged as compelling topics for researchers. Several methods exist to enhance the separation performance and anti-fouling properties of polymer membranes. Among these, incorporating additives into the membrane polymer matrix stands out as a cost-effective, straightforward, readily available, and efficient approach. The use of Mg-based LDHs, either in combination with other materials or as a standalone additive in the polymer membrane matrix, represents a promising strategy to bolster the separation and anti-fouling efficacy of flat sheet mixed matrix polymer membranes. This review highlights Mg-based LDHs as high-potential additives designed to refine flat sheet mixed matrix polymer membranes for applications in wastewater treatment and brackish water desalination. [Display omitted] [ABSTRACT FROM AUTHOR]

Membrane performance, regarding water flux and water recovery during membrane distillation (MD), is crucial during desalination. In this study, the membrane performance was improved using 3D-printed macro-structured feed spacers. Typically, 3D-printed feed spacers offer maximum flexibility for designing favorable geometrical transformations. The role of 3D-printed spacers in enhancing the permeate flux and recovery in direct contact membrane distillation (DCMD) has been thoroughly investigated. A comparative assessment was performed for various designs of 3D printed feed spacers with varying hydraulic diameters and filament thicknesses. An economical, biocompatible, and highly robust 3D-printed membrane spacer was developed using polylactic acid (PLA), which has a high elastic modulus. PLA is a biodegradable and environmentally friendly material. The thermal stability of PLA materials is advantageous for temperature-driven MD processes. PLA filaments were subjected to thermogravimetric analysis (TGA) for evaluating thermal stability. It provides structural support for the membranes and enhances mass movement through the membrane surface. In addition, these 3D-printed membrane spacers employing PLA have proven superior to conventional layouts in performance. These 3D-printed feed spacers were rationally designed to create a high flow disruption, which can lead to increased turbulence, thereby increasing the permeate flux. The overall results suggest that the 3D printed spacers can be ranked like TR˃DI ≈ SQ ˃ CR in terms of water flux. Eventually, the presence of 3D-printed spacers may prevent the external foulant layer onto the surface of membrane. Thus, the 3D printed spacers were ranked as TR˃DI ≈ CR≈ SQ for fouling mitigation ability. Furthermore, the used PVDF membrane with 3D printed spacers indicates lower hydrophobicity reduction, 11–14%. Therefore, this paper illustrates a facile approach to designing 3D-printed feed spacers that exhibit increased membrane performance in MD operation. [Display omitted] • 3D printed macro-structured spacers for enhanced water flux and recovery. • Feed spacers enhanced permeate flux by 22%. • Comparative assessment of 3D printed feed spacers in membrane performance. • Enhanced hydraulics as well as reduced fouling impacted by 3D printed spacer with tweaked geometry. • Improved proposal for development and analyzing a futuristic 3D printed feed spacer. [ABSTRACT FROM AUTHOR]

Mixing additives into a polymeric membrane constitutes an easy way to change their properties. Polyelectrolyte complexes (PECs) (polyelectrolytes combined via electrostatic interaction) are good materials for this due to their hydrophilicity, tunable surface charge, and stable structure. In the present study, membranes containing PECs were obtained using three methodologies: complexation before, after, and during membrane formation. The chosen polyelectrolytes were 4-fluorophenyl sulfone-terminated poly(diallylpiperidinium hexafluorophosphate) and sulfonated poly(ethylene terephthalate); the polymeric matrix was polyethersulfone. Fourier transform infrared spectroscopy confirmed the presence of PECs in the membranes. Scanning electron microscopy images of the membranes showed a dense skin and porous sub-layer, with variations in the thickness of the dense layer influenced by the presence of polyelectrolytes. The increase in water vapor permeability indicated that the complexes alter the hydrophilic profile of the membranes. The thermogravimetric curves showed different thermal behaviors depending on the interaction between the polyelectrolytes. All membranes demonstrated enhanced retention of Remazol red dye during filtration, with retention rates exceeding 95%. Notably, the Blend membrane exhibited the highest retention (over 98%) of the dye. [ABSTRACT FROM AUTHOR]

Polyethersulfone membrane is easy to be polluted, and the negative surface would help enhance improve the permeability and the anti-pollution performance; so how to anchor polymer brushes with negative groups to polyethersulfone membrane surface is a challenge. In this paper, polymer brushes of poly(2-acrylamide-2-methylpropanesulfonic acid sodium salt) is first grafted to carbon nanotubes to form an organic-inorganic hybrid additive, which is further anchored onto the membrane surface of polyethersulfone by blending method. The graft reaction is proceeded by surface initiated electrochemical atom transfer radical polymerization, where the introduction of electrochemical part is because it could help better control the growth of polymer brushes compared with the pristine atom transfer radical polymerization process. The carbon nanotubes grafted with poly(2-acrylamide-2-methylpropanesulfonic acid sodium salt) could anchor on the membrane surface because the there is a self-assemble process of organic-inorganic hybrid additive during phase inversion method, where the inorganic part carbon nanotubes firmly embedded into the membrane and the organic part can be fixed on membrane surface. The polyethersulfone membrane exhibits enhanced surface hydrophilicity, improved the permeability of the membrane, and good anti-fouling performance due to the negative charge and electrostatic repulsion brought by anionic surface of the modified membrane. When the mass of nanotubes grafted with poly(2-acrylamide-2-methylpropanesulfonic acid sodium salt) in the casting solution is 20 mg, the water flux can reach 365.5 L m−2 h−1, and the rejection ratios of both BSA and CR are close to 100% with good flux recovery and anti-fouling effect performance. [ABSTRACT FROM AUTHOR]

Even though there are numerous CO2 capture technologies (such as chemical and physical absorption), investigators are still trying to come up with novel methods that can minimize the energy requirements for their integration into thermal power plants, as well as the CAPEX and OPEX expenses. In this work, the technical and financial aspects of integrating two-stage polymeric membranes into a coal-fired power plant with a capacity of 330 MW were examined. The study researched the membrane post-combustion CO2 capture process utilizing CHEMCAD version 8.1 software with several parameters and an expander to decrease the total cost. The simulation showed promising results regarding reducing power consumption after using an expander for both a high capture rate (>90%) and a CO2 concentration of more than 95%. Thus, the CO2 captured cost decreased from 58.4 EUR/t (no expander) to 48.7 EUR/t (with expander). [ABSTRACT FROM AUTHOR]

Tempranillo red wines were partially dealcoholized (-3 v/v%) by osmotic distillation (OD) with membranes. First, polypropylene (PP) Iiqui-Cel3M (3M) hollow fiber membrane modules were applied at 11 and 15 °C to study the effect of the removal of ethanol on the aroma of a certain wine. The influence of both temperatures was evaluated in terms of ethanol flux and aroma losses. Afterwards, two additional wines with different compositions were dealcoholized. The impact of the initial concentration of aromas on achieving a final product with an appealing aroma profile was studied, displaying the three wines a comparable aroma retention. Membrane OD was carried out with two additional hollow fiber membrane modules: another PP module (Zena) with a higher pore size, and a superhydrophobic PVDF module (Polymem). The latter gave rise to a partial dealcoholized wine with an aroma profile very similar to that of the pristine wine. [ABSTRACT FROM AUTHOR]

This article provides a comprehensive review of the state-of-the-art technology of polymeric mixed-matrix membranes for CO2/CH4 separation that can be applied in medium, small, and domestic biogas systems operating at low pressures (0.2–6 kPa). Critical data from the latest publications of CO2/CH4 separation membranes were analyzed, considering the ratio of CO2/CH4 permeabilities, the CO2 selectivity, the operating pressures at which the membranes were tested, the chemistry of the polymers studied and their gas separation mechanisms. And the different nanomaterials as fillers. The intrinsic microporous polymers (PIMs) were identified as potential candidates for biomethane purification due to their high permeability and selectivity, which are compatible with operation pressures below 1 bar, and as low as 0.2 bar. This scenario contrasts with other polymers that require pressures above 1 bar for operation, with some reaching 20 bar. Furthermore, the combination of PIM with GO in MMMs was found to not influence the permeability significantly, but to contribute to the membrane stability over time, by preventing the structural collapse of the membrane caused by aging. The systematic analysis here presented is a valuable resource for defining the future technological development of CO2/CH4 separation membranes for biogas biorefining.

The separation of CO2 has been recognized as a potential approach to address the impacts of climate change resulting from the emission of flue gases into the environment. Efficient separation technologies are required to effectively remove CO2 from flue gases. To resolve this problem, membrane-based gas separation is considered an economically viable and energy-efficient technology over conventional techniques. Functional polymeric membranes have gained a lot of interest for their attractive gas separation performance. Thus, this work aims to critically review the recent developments of functional polymeric membranes designed for CO2 separation from flue gases. Starting with a background on flue gases and polymeric membranes, a brief discussion on Robeson's upper bound for CO2/N2 separation is provided. After that, a detailed analysis of the current advancements in different membrane modification approaches, such as mixed matrix, grafting, layer-by-layer assembly, and interfacial polymerization, for improved performance of polymeric membranes is provided. Furthermore, the effect of CO2 on polymeric membranes (plasticization and aging), the current global market and key market players in the membranes-based gas separation field are discussed thoroughly. Finally, a concise remark on the future directions of polymeric membranes for CO2 separation from flue gases is presented.

The OphthalMimic is a 3D-printed device that simulates human ocular conditions with artificial lacrimal flow, cul-de-sac area, moving eyelid, and a surface to interact with ophthalmic formulations. All tests with such a device have used a continuous artificial tear flow rate of 1 mL/min for 5 min. Here, we implemented protocol variations regarding the application time and simulated tear flow to increase the test’s discrimination and achieve reliable performance results. The new protocols incorporated the previously evaluated 0.2% fluconazole formulations containing or not chitosan as a mucoadhesive component (PLX16CS10 and PLX16, respectively) and novel moxifloxacin 5% formulations, either in a conventional formulation and a microemulsion (CONTROL and NEMOX, respectively). The flow rate was reduced by 50%, and a pre-flow application period was also included to allow formulation interaction with the membrane. The OphthalMimic model was used with both polymeric and hydrogel-based hybrid membranes, including a simulated eyelid. Lowering the flow made it feasible to prolong the testing duration, enhancing device discrimination potential. The hydrogel membrane was adequate for testing nanostructure formulations. The OphthalMimic device demonstrated once again to be a versatile method for evaluating the performance of ophthalmic drug formulations with the potential of reducing the use of animals for experimentation.

Recently, the plant polyphenols have attracted much attention for membrane modification, especially in surface coating application. In this study, the synthesis of catechol-amine coating solutions was evaluated at different pH conditions and with different concentrations of tannic acid and tetraethylenepentamine in order to determine the relationship between chemical structure and mechanism in the oxidation reaction. The reactivity of catechol and amine groups in the formulation was measured using UV–Vis spectroscopy and observation of the change in colour of the coating solutions. Then, the deposition of catechol-amine coating solutions was applied onto the hydrophobic polyvinylidene fluoride (PVDF) membrane. The formulation results show significant differences in alkaline conditions, revealing the role of catechol groups in the oxidation of polyphenolics. The reactions of quinone and amines to form crosslinks by Michael addition and Schiff base reactions were observed at different concentrations of each compound in coating solution. In addition, the negative charge of hydrophilic and underwater oleophobic-coated PVDF membrane was confirmed by surface zeta potential analysis. The morphological surface of modified membrane is rougher due to that coating deposition was also examined using scanning electron microscopy (SEM). Furthermore, the performance of modified membrane is comparable with the commercial hydrophilic membrane in terms of fluxes and separation efficiency of emulsion solution. [ABSTRACT FROM AUTHOR]

Comprising advanced materials like polyvinylidene fluoride (PVDF) for mechanical stability and biofouling prevention and polyvinylpyrrolidone (PVP) for hydrophilicity, membranes enable selective filtration, retaining larger particles and external contaminants in wastewater treatment. Incorporating activated carbon during manufacturing is a strategic approach to enhance membrane (AC-CO2 membrane) properties, leveraging its high surface area and adsorption capacity. This study produced mixed polymeric membranes by combining PVDF, PVP, and activated carbon (AC-CO2), using N-Methyl-2-pyrrolidone (NMP) as the solvent. These membranes were employed for the filtration of phenolic compounds, particularly phenol. In an AC-CO2 membrane formulation with 1.3 g of PVP, 1.15 g of PVDF, 8.8 mL of NMP, and 2.5 g of AC-CO2, with thickness variations of 150 µm and 300 µm, approximately 56.77% and 90.35% of 50 mg/L of phenol in model wastewater were removed within 5 min, respectively, with breakthrough occurring at 15 min. Finally, this study developed a hydrophilic membrane with alkaline characteristics and a neutral pH point of zero charge (pHPZC), establishing the feasibility of employing these membranes to treat model wastewater containing phenolic compounds. The prospect of scaling up for practical applications presents a promising avenue for future investigations. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) separation with membrane technology has become the focus of researchers over the past decades due to its lower energy consumption and cheaper alternative. Mixed matrix membrane (MMM) of poly(4-methyl-1-pentene) (PMP) with nano fumed silica particles was studied to determine the feasibility of using MMM to separate CO2 from nitrogen (N2) gas. The critical concentration of PMP (7 wt%) was utilized to form the membrane in this study in order to ensure the polymer chain entanglement occurs to form a dense structure. Agglomeration of particle can be observed on the surface with scanning electron microscopy (SEM) imaging with 10 and 15 wt% of nano fumed silica loading in PMP matrix. This observation is further confirmed with energy-dispersive X-ray (EDX) mapping across the cross-sectional area which shows clustered nano fumed silica particle with loading of 10 and 15 wt%. With 7.5 wt% filler loading and at 1 bar, the MMM seems to give the best gas permeance performance with CO2 permeance of 4.62 GPU (100.54 Barrer) and N2 permeance of 0.20 GPU (4.31 Barrer) which makes the highest ideal selectivity to be about 23, which was the highest ideal selectivity achieved in this study. Meanwhile, when the pressure was increased from 1 to 7 bar, the CO2 permeability increased almost linearly followed by a steady decline in CO2/N2 ideal selectivity. [ABSTRACT FROM AUTHOR]

The modified Claus process is one of the most commonly used methods for hydrogen sulfide conversion into sulfur. However, one of the problems of this unit is the presence of benzene, toluene, and xylene (BTX) compounds at the inlet of the catalytic reactors that can deactivate the catalyst and decrease the efficiency of the sulfur recovery unit. One of the methods of BTX destruction in a furnace is to increase its temperature by increasing the oxygen concentration in the inlet air. In the present work, the application of polymeric membranes for the destruction of BTX was investigated by modeling and simulating a sulfur recovery unit and a membrane unit. The numerical results obtained from the simulations were validated successfully with industrial and experimental data for both sulfur recovery and membrane units. The simulation results for an industrial case study indicate that using five PI carbon membrane units with a total area of 26.82 m2 can increase the concentration of oxygen in the inlet air to a level of 60%. In this condition, the reduction in BTX compounds can also be increased up to 59%. Furthermore, for two-stage membrane configuration, by employing five two-stage membrane units with a total area of 58.3m2, the oxygen concentration increases to 82%, and the reduction in BTX compounds will be 75%. [ABSTRACT FROM AUTHOR]

Membrane contactors using microporous membranes for acid gas removal have been extensively reviewed and discussed. The microporous membrane acts as a fixed interface between the gas and the liquid phase without dispersing one phase into another that offers a flexible modular and energy-efficient device. The gas absorption process can offer a high selectivity and a high driving force for transport even at low concentrations. Using hollow fiber, gas–liquid membrane contactors are a promising alternative to conventional gas absorption systems for acid gas capture from gas streams. Important aspects of membrane contactor as an efficient energy device for acid gas removal including liquid absorbents, membrane characteristics, combination of membrane and absorbent, mass transfer, membrane modules, model development, advantages and disadvantages were critically discussed. In addition, current status and future potential in research and development of gas–liquid membrane contactors for acid gas removal were also briefly discussed. The most essential factors of membrane contactors for CO2 absorption/stripping are also discussed, including the hydrophilicity and hydrophobicity of the absorption materials in the membranes, as well as other models published in the literature. The benefits and drawbacks of gas–liquid contactor membranes in CO2 absorption/stripping are also investigated, and the technique is compared to existing separation methods. The technology's present condition and potential directions are explored, as well as some recommendations for further study in order to commercialize. [ABSTRACT FROM AUTHOR]

A sensitive analysis of CO2 capture from a coal-fired power plant of 600 MW with membrane technology based on post-combustion process is demonstrated. This study aimed to determine the influence of the membrane materials used (e.g., CO2 permeability was considered at 300, 1000, and 3000 GPU) on coal-fired power plant performance by investigating various parameters, such as the membrane number of stages, membrane surface area, and compressors' pressure. The membrane surface area required varied from 200,000 to 800,000 m2 to procure no less than 99% purity. The total power plant efficiency was reduced by different values after integrating membrane CO2-capture technology based on the process design; nevertheless, the efficiency is profitable by around 13.5% when three membrane stages were harnessed instead of a two-stage configuration. Consequently, the levelized cost of energy (LCOE) decreased from 157 EUR/MWh (two stages of membrane) to 134 EUR/MWh (three stages of membrane). [ABSTRACT FROM AUTHOR]

The wound dressings fabricated by polymers and oregano essential oil (OEO) can be very effective as a hydrogel. The current study has been focused on fabricating the hydrogel membranes of oregano oil encapsulated as an antibacterial agent into sodium alginate (SA) solution by solvent casting method and then evaluated the antibacterial, antioxidant activity, and physicochemical performance of SA/OEO-based polymeric membranes. The polymeric interactions, surface morphology, water absorption capability, thermal stability, and encapsulation efficiency were investigated by FT-IR, SEM, swelling ratio, DSC, and encapsulation efficiency. The percentage encapsulation efficiency of essential oil was 40.5%. FTIR validated the presence of molecular interaction between individual components. SEM images showed a rough and porous appearance for hydrogel membranes. Moreover, DSC showed that the fabricated membranes were thermally stable. The inclusion of more content OEO decreased swelling ratios. The antioxidant test was carried out by DPPH assay and antibacterial test through disc diffusion method against microbes. The results revealed that membranes containing the highest content of OEO had more excellent antioxidant and antibacterial efficacy. Therefore, the polymeric membranes of sodium alginate loaded with oregano essential oil can be employed as an effective wound-healing candidate. [ABSTRACT FROM AUTHOR]

Peusner’s network thermodynamics (PNT) is one of the more important formalisms of nonequilibrium thermodynamics used to describe membrane transport and the conversion of the internal energy of the system into energy dissipated in the environment and free energy used for the work involved in the transport of solution components in membrane processes. A procedure of transformation the Kedem–Katchalsky (K-K) equations for the transport of binary electrolytic solutions through a membrane to the Kedem–Katchalsky–Peusner (K-K-P) equations based on the PNT formalism for liquid junction potentials was developed. The subject of the study was a membrane used for hemodialysis (Ultra Flo 145 Dialyser) and aqueous NaCl solutions. The research method was the L version of the K-K-P formalism for binary electrolyte solutions. The Peusner coefficients obtained from the transformations of the K-K formalism coefficients for the transport of electrolyte solutions through the artificial polymer membrane were used to calculate the coupling coefficients of the membrane processes and to calculate the dissipative energy flux. In addition, the dissipative energy flux, as a function of thermodynamic forces, made it possible to investigate the energy conversion of transport processes in the membrane system.

Natural gas, an important source of hydrogen, is expected to be crucial in the transition to a hydrogen-based economy. The landscape of the gas processing industry is set to change in the near future with the development of highly acidic sour gas wells. Natural gas purification constitutes a major share of the gas separation membrane market, and the shift to low-quality sour gas wells has been mirrored in the trends of membrane material research. Purification also constitutes the major portion of the cost of natural gas, posing implications for the cost of hydrogen production. This review provides an update on the current state of research regarding polymeric membranes for H2S removal, along with CO2 separation, from natural gas that is used for hydrogen production via steam methane reforming. The challenges of adapting polymeric membranes to ternary H2S/CO2/CH4 separations are discussed in detail. Key polymeric materials are highlighted, and the prospects for their application in H2S removal from natural gas are evaluated. Finally, the growing interest in H2 production from H2S is discussed. Advances in the membrane industry and the emergence of new membrane materials may significantly improve the commercial viability of such processes. [ABSTRACT FROM AUTHOR]

In this study, we aimed to modify polymeric membranes by incorporating magnetic nanoparticles (NPs) to enhance their properties. The structural and chemical properties of magnetic NPs of iron oxide were prepared via a wet chemical method. Iron oxide nanoparticles (IONPs) were used as the core and were coated with polymers polyvinyle alcohol (PVA) and polyvinylpyrrolidone (PVP). The prepared samples were cast on a glass substrate using a casting knife. The aim of this study is the use of a specific type of magnetic NPs, coated with a polymer, and their application in membrane modification. We employed a facile synthesis method to coat the IONPs with the polymer and characterized the resulting material using various techniques, including X-ray Diffraction (XRD), scanning electron microscope (SEM), Fourier Transform Infrared (FTIR) Spectroscopy, and UV/Visible (UV–Vis) Spectroscopy for structural, morphological, chemical bonding, and optical properties studies. Our results show that the modified polymeric membranes exhibited improved properties, such as increased permeability and selectivity. We also observed that the magnetic NPs helped in the easy recovery of the modified membranes using an external magnetic field. Some agglomeration of IONPs was also observed, and the polymer membrane caused a decrease in crystallinity of IONPs. Overall, this study presents a promising approach for enhancing the properties of polymeric membranes using magnetic NPs and can potentially have practical applications in various fields, such as water treatment, food processing, and biotechnology. [ABSTRACT FROM AUTHOR]

Fulvic acids (FAs) are significant natural organic compounds produced during the decomposition of plants and animals. There is great demand for FAs in pharmaceutical, cosmetic, and industrial applications. However, their use is declining due to the tedious purification process. This study developed a method to purify FAs extracted directly from leonardite-rich humic substances. The method introduces a permeation cell integrated with a polymer inclusion membrane to separate target impurities related to FAs from extractants and humic raw material sources. Polymeric membranes were prepared using fixed proportions of cellulose triacetate, tri octyl methylammonium chloride, tributyl phosphate, and 2-nitrophenyl pentyl ether. The purified fulvic acids, feed phase, and stripping phase products were characterized using SEM, EDX, FTIR, and UV-Vis. Fluorescence spectroscopy analysis was also performed to compare the purity intensity of fluorescence spectra of the respective components of the feed and stripping phase. In terms of purification, the membrane obstructed the passage of foreign ions and unwanted particles and allowed only FAs molecules to pass through. This research affirms that the present method is more effective, cheaper, and more convenient than the classical method for FAs purification. [ABSTRACT FROM AUTHOR]

As the industrial revolution progresses, carbon dioxide (CO2) and sulfur dioxide (SO2) are major concerns because they are the main contributors to greenhouse gases. The concentration of these harmful gases in the industry is very high, which is emitted by workers and industrial materials. Therefore, it is required to maintain a safe percentage of CO2, SO2, and other harmful gases in the air of industry and ensure safety from fire accidents. This paper presents a compressor driven system that could capture harmful gases including CO2 and SO2 from the polluted air of different industries and households. The captured and separated CO2 works as a fire extinguishing agent to safeguard fire accidents for large industries and households. Thus, this system ensures a protected working place and a healthy atmosphere for industrial workers. Besides, this system can be applied in place of the exhaust gas recirculation (EGR) system in small industries and for a four-wheeler, internal combustion engine, as this system could capture and separate the harmful carbon dioxide and sulfur dioxide. This paper also presents a developed model of different polymeric membranes to simulate the separation of carbon dioxide after the post-combustion process. Computational Fluid Dynamics (CFD) has been performed by COMSOL 5.5 to observe the carbon dioxide separation by polymeric membranes like polycarbonate (0.07 mol/m3) and polytetrafluoroethylene (0.1 mol/m3) polymeric membranes for specific pore sizes which is comparable to experimental data (0.05 mol/m3). [ABSTRACT FROM AUTHOR]

Polymeric membranes have proven to be an effective method for the treatment of contaminated waters. Many factors influence their performances including the operating parameters, fabrication process and conditions, and their modifications using different additives. Introduced as additives, nanoparticles are capable of enhancing the membrane performance via their intrinsic properties which include their morphology, core size, and chemical nature. Nevertheless, some common problems such as nanoparticle agglomeration or leaching and the formation of defective areas, occur during the membrane fabrication. These issues depend on several factors which were observed to influence the membrane morphology and structure and consequently influence the treatment effectiveness. Accordingly, different strategies were investigated to avoid these issues. In this review paper, the effects of three different nanoparticles namely Titanium, Aluminum, and Silica on the performance of the modified membranes devoted to the treatment of organic waste streams will be thoroughly investigated. In addition, major effects related to the fabrication conditions including various challenges encountered during the membrane manufacturing and the different strategies used to improve performance will be thoroughly discussed. [ABSTRACT FROM AUTHOR]

Concerns about climate change, the greenhouse gases effect and global warming have become the motivation to explore new technology to separate CO2 gases. In this work, poly(4-methyl-1-pentene) (PMP) was fabricated to determine its feasibility to separate CO2 from N2 gas and to elucidate the influence of the membrane structure on its separation performance. This study consists of two main parts where a full dense PMP membrane with various PMP concentrations was fabricated first as a controlled sample. 5 wt% PMP fabricated at 20 °C was the best condition to fabricate the membrane based on the gas permeance test. The CO2 and N2 permeance is 5.91 GPU (76.46 Barrer) and 0.51 GPU (6.61 Barrer), respectively, and the CO2/N2 selectivity is 11.57. To prepare a membrane with the anisotropic structure, a non-solvent induced phase separation method was employed. Similar PMP concentration and drying conditions to the dense membrane were used to fabricate the anisotropic PMP membrane for comparison purposes. The influence of dry phase inversion time was tested. It was found that the dry phase inversion time has a significant impact on the porosity of the substructure but not the thickness of the dense layer. Nevertheless, 40 s dry phase inversion time appears to be the best duration to fabricate the anisotropic PMP membrane. The CO2 permeance was improved by 10 times compared to the full dense membrane. However, the CO2/N2 selectivity is halved to the dense PMP membrane, mainly due to the thin dense layer and porous substructure of the membrane. [ABSTRACT FROM AUTHOR]

In this study, with the help of reactive monomers, crosslinkers, and photoinitiator that detect H2S in various matrices, an H2S sensitive fluorescence sensor polymerizes under ultraviolet (UV) light was developed. To this goal, a polymeric membrane was prepared, and the characterization of the membrane was carried out with Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) methods. Afterward, appropriate conditions were identified, the excitation wavelength was determined as 370 nm, and the emission wavelength was determined as 425 nm. It was established that the fluorescence intensity of the prepared polymeric membrane decreased in the presence of H2S. A detailed analysis was executed to determine the sensor's most suitable pH value and time. It was found that the optimum pH was 8.0, and the optimal duration was 15 s. It has been calculated that the linear range of the developed method is 2.19 × 10–8– 6.25 × 10–7 M, and the detection limit (LOD) is 7.37 × 10–9 M. The effect of some possible interfering ions was investigated, and it determined that the sensor had excellent selectivity. In addition, the sensor used to determine H2S can be used at least 100 times. The recovery percentages were 102.1%–103.2%, and 104.6%, using tap water samples. In terms of providing reliable, fast results, high sensitivity, reusable, low cost, and ease of use, the developed fluorimetric sensor, compared to standard methods, has become more advantageous. [ABSTRACT FROM AUTHOR]

Ion-selective electrodes or sensors are preferred by researchers in the determination of various ions since they provide very high selectivity and wide concentration range in environmental, industrial, clinical, agricultural, medicinal and routine laboratory analyses. Cadmium, a toxic heavy metal, poses a significant risk to humans and animals due to its wide use in the industry. Today, many analytical methods have been proposed for the determination of cadmium ions in various samples and their working conditions have been determined. One of these methods is potentiometric ion-selective electrodes, which have certain advantages over alternative methods in terms of multiple parameters. In this review, we provide a comprehensive description of the available cadmium(II)-selective polymeric membrane potentiometric sensors and their applications on different environmental samples. [ABSTRACT FROM AUTHOR]

Produced water (PW) has been generated in a huge amount representing the largest volume waste stream. Membrane technology has found a leading ability in treating PW due to its significant advantages, such as lower cost, easy installation, and being environmentally friendly. Mixed matrix membranes (MMMs) have received significant research interest due to their flexibility, multifunctionality enhances the membrane performance with increasing selectivity, permeability, robustness, mechanical strength, and resistance to fouling. This mini‐review paper identifies the utilization of different membranes for treating PW. It also gives a review of different types of MMMs with specific fillers for the application of PW treatment. Lastly, some methods to enhance the performance of mixed matrix membranes have been highlighted. The issues and challenges in membranes are also discussed. Practitioner Points: Mixed matrix membranes (MMMs) are a potential membrane type for PW treatment.This mini‐review paper identifies the use of several membranes to treat PW. It also examined various types of MMMs containing specific fillers for the application of PW treatment.Methods for improving the performance of mixed matrix membranes have been highlighted, including the use of novel materials, surface modification, and cross‐linking.The issues and challenges in membranes are also discussed. [ABSTRACT FROM AUTHOR]

Moringa oleifera (M. oleifera) has been utilized in conventional drug to treat illnesses associated with inflammation and wound healing. However, its utilization in tissue engineering application has not been explored yet. Reliable materials and carrier system are required to blend M. oleifera for sustainable therapeutic purpose. In this study, M. oleifera leave extracts were incorporated into electrospun polycaprolactone (PCL) nanofibrous membrane at various concentrations (19 wt%, 39 wt% and 59 wt%). A standard composition of 1 wt% silver nanoparticles (AgNPs) was also included to improve the membrane performance. The membranes were characterized with SEM–EDX, AFM and ATR-FTIR analyses. Further performances on the wettability, thermal, antibacterial and biocompatibility of the membranes were detailed assessed. The PCL/M. oleifera/AgNPs (PMA) membranes were viewed with smaller nanofiber diameter, greater surface roughness and higher wettability following the incorporation of M. oleifera. The notable appearances of C=C and N–O functional groups were observed on the PMA membranes with the composition of less than 1 wt% Ag. The PMA membranes were clarified thermally stable with a single step thermal decomposition. The antibacterial efficacy of the PMA membranes was prominent on Staphylococcus aureus (S. aureus) than Escherichia coli (E. coli). Importantly, the PMA membranes have enhanced the human platelet coagulant behavior significantly (p ≤ 0.05), up to 39% for the PMA-3. The membranes are considered hemocompatible with a hemolysis index of ≤ 5%. These results demonstrate that the PMA electrospun membranes have a potential to be used in tissue engineering application due to the therapeutic properties of M. oleifera. [ABSTRACT FROM AUTHOR]

The aim of this study is to examine the effects of modification of polymeric polyacrylonitrile and polyetherimide membranes with a polymeric additive, namely polyvinylpyrrolidone, on membrane performance in a submerged membrane bioreactor under different operating conditions. For this purpose, the membrane filtrations were performed with raw and modified membranes after the activated sludge was acclimated in the submerged membrane bioreactor to two different sludge retention times and two different organic loading rates. While the performance of all membranes increases with an increase in sludge retention times, the increase in organic loading rates decreases soluble microbial products. The modification with polyvinylpyrrolidone provides higher total permeate volumes with the higher rejection of soluble microbial product fractions, especially in polyacrylonitrile membranes. The rejections of carbohydrate fraction of soluble microbial products increase by the modification of both membranes with polyvinylpyrrolidone. Membrane fouling is determined to be inversely proportional to the membrane pore size. Scanning electron microscope analyses confirm that membrane fouling increased at low sludge retention time and high organic loading rate. The carbohydrates and proteins are approved as the main foulants on the membrane surface with Fourier transform infrared spectroscopy. As a result, modification of polyacrylonitrile polymer with polyvinylpyrrolidone is determined as an appropriate approach in order to increase treatment efficiency and improve membrane lifetime in submerged membrane bioreactor operated at high sludge retention time. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) capture utilising membrane technology have become the interest of research due to its low carbon footprint, feasible fabrication process and scalability in its operation. In this study, anisotropic polyethersulfone (PES) membrane was fabricated at various concentration ranging from 20 wt% to 35 wt% without the use of any additives. This study revealed that the finger-like structure disappeared with increased polymer dope concentration which was associated with increased viscosity of the dope solution. Moreover, the surface porosity of the membrane also virtually reduced with increased PES concentration as observed with the SEM images. The pure gas permeation test was also consistent with the observed morphology of the membrane. Membrane made with 20 wt% of PES dope solution exhibits the highest gas permeance which was 154.9 GPU at 2 bar while the CO2/nitrogen (N2) and CO2/methane (CH4) ideal selectivity was close to that of Knudsen's selectivity value. With increased PES concentration, the CO2 gas permeance reduced drastically accompanied by enhancement on the CO2/N2 and CO2/CH4 ideal selectivity. The critical concentration of PES dope solution obtained by plotting the PES dope concentration against viscosity was 29.4 wt%. With critical concentration of the dope solution, the CO2 permeance was recorded to be 8.1 GPU while the CO2/N2 and CO2/CH4 ideal selectivity were recorded to be 2.13 and 1.48, respectively at the pressure of 2 bar. [ABSTRACT FROM AUTHOR]