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Casein is an important protein in the raw milk and many approaches have been established to separate casein to make cheese. This study mainly deals with the analysis of casein protein (19 kDa, pI 4.6) transport characteristics through ultrafiltration (UF) membranes. Polysulfone (PS) based polymer membranes are used and modified with polyethylene imine (PEI), polydiallyl dimethyl ammonium chloride (PDDA) and polyacrylic acid (PAA). The fabricated membranes are characterized by contact angle and Fourier transforms infrared (FTIR) spectroscopy. The UF process was conducted with a dead-end filtration unit and the volumetric flux and transmission values are recorded and that varies with pressure and pH. The experimental results are explained using the concentration polarization and irreversible thermodynamics model. The characteristics of the transport of casein are determined from the values of the parameters such as the solute concentration near the surface of the membrane [Cm], the solute permeability [Pm], mass transfer coefficient [k], and the reflection coefficient [σ]. From the results, it is concluded that the casein transport through the UF membrane was controlled by convection with decrease in casein rejection. Although, this model predicts the transmission behavior as a function of flux and supports the experimental results for both membranes. [ABSTRACT FROM AUTHOR]

A novel organic-inorganic nanocomposite membrane with green material based is prepared by incorporating sulfonated holey graphene oxide (SHGO) into nanocrystalline cellulose/polyvinyl alcohol (NCC/PVA) matrix as polymer electrolyte membrane (PEMs) via solution casting method. Introducing sulfonic acid group in graphene oxide (GO) yielded sulfonated graphene oxide (SGO) and the hole effect on the graphitic plane of GO for SHGO on NCC/PVA significantly improves the proton conductivity of membranes by creating more interconnected proton transfer channels and promoting proton transfer across the membrane. Highest proton conductivity values of 1.1 × 10-2 S cm-1 is obtained by NCC/PVA-SHGO-1.0 at 80o C under 100% relative humidity (RH). Additionally, mechanical and chemical stability tests indicate an enhancement in those properties. However, hydrogen permeation has slightly increase due to the hole effect. Increasing SHGO loading in NCC/PVA has improve its properties and performance. At 80o C, under 100% RH, NCC/PVA-SHGO-1.0 exhibit the highest power density and current density of 31.4 mW/cm2 and 60.2 mA/cm2, respectively which is three times higher compared to pristine NCC/PVA. This work summarise that incorporating SHGO into NCC/PVA membranes can significantly improves its properties, performance and membrane durability which entitle them as a potential candidate for PEMs. [Display omitted] • Sulfonation and the holey graphitic plane structure in SHGO construct additional pathways for proton transport. • Embedding fillers generate stiffer and mechanically stable PEMs as compared to pristine NCC/PVA. • At 80° C, under 100% RH, NCC/PVA-SHGO-1.0 exhibit three times higher fuel cell performance compared to pristine NCC/PVA. [ABSTRACT FROM AUTHOR]

Defined as an assembly of polymer chains which are tethered by one end to a surface or an interface, polymer brushes have found many applications. In particular, grafting of hydrophilic polymer brushes to the membrane surface was used to mitigate fouling of filtration membranes. As well, hydrophobic polymer brushes were grafted on top of a solid substrate to be used for organic selective pervaporation. In this work, grafting of hydrophobic brushes to the surface of membranes for membrane distillation (MD) is proposed to prevent MD membranes from wetting. This is not an experimental work but a computer simulation of designing the polymer brush or patterned polymer brush to optimize their effect on wetting prevention. It was found that such an effect increases with an increase in the distance between brushes, the contact angle and the radius of the cylindrical polymer brush. Considering the decrease in the effective area of the membrane used for vapor permeation by grafting of polymer brush, the optimal distance between the brushes was found to be twice as large as the brush diameter for millimeter-sized brush and three times as large as the brush diameter of micro- or nanometer sized brushes. [ABSTRACT FROM AUTHOR]

β-glucans are soluble fibers found in cereal compounds, including barley, oats etc., as an active component. They are used as a dietary fiber to treat cholesterol, diabetes and cardiovascular diseases. These polysaccharides are important because they can provide many therapeutic benefits related to their biological activity in human like inhibiting tumour growth, anti-inflammatory action, etc. All these activities were usually attached to their molecular weight, structure and degree of branching. The present manuscript reviews the background of β-glucan, its characterization techniques, the possible ways to extract β-glucan and mainly focuses on membrane-based purification techniques. The β-glucan separation methods using polymeric membranes, their operational characteristics, purification methods which may yield pure or crude β-glucan and structural analysis methods were also discussed. Future direction in research and development related to β-glucan recovery from cereal were also offered. [ABSTRACT FROM AUTHOR]

• A CS/LSMM/mPTA-Si composite membrane was developed for DMFC applications, enhancing hydrophilicity, proton transport, and stability. • Optimal mPTA loading achieved a peak power density of 53.56 mWcm−2 at 121.4 mAcm−2. • Optimal DMFC performance was achieved using hot-pressing under 5 tonnes, 90 s, and 135 °C with the CS/LSMM/0.25mPTA-Si setup. • The membrane remained stable under 100% humidity despite minor swelling. Direct Methanol Fuel Cells (DMFCs) research focuses on improving Proton Exchange Membranes (PEMs) to enhance ion exchange and proton conduction. Although Nafion® is stable both chemically and thermally, however it suffers methanol crossover. In this study, a novel composite PEM was introduced by blending chitosan (CS), hydrophilic surface modifying macromolecules (LSMM), and mesoporous siliceous phosphotungstic acid (mPTA-Si) at varying loadings. Notably, the CS/LSMM membrane with 0.25 wt% of mPTA-Si content and optimized hot pressing technique conditions (5 tonnes, 90 s and 135 °C) exhibited superior performance, with a proton conductivity of 0.097 S/cm and a power density of 60 mW/cm2. Additionally, properties such as tensile strength and ion exchange capacity surpassed those of pure CS by 14 % and 56.12 %, respectively. The unique characteristics of CS, mPTA, and LSMM collectively contributed to the promising attributes of the CS/LSMM/0.25mPTA-Si membrane for enhancing fuel cell performance. [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]

• Thermal stable SPEEK membrane was fabricated with halloysite nanoclay and functionalized GO nanocomposites. • The silane and sulfonic acid group in the nanocomposite SPEEK membrane increased IEC and low methanol permeability. • The nanoclay and fGO membranes have shown significant proton conductivity and power density than pristine SPEEK membrane. Membrane-based fuel cells, particularly methanol-based fuel cells, are thriving areas with high efficiency, less material consumption, and low emission of pollutants. But commercial membranes have less thermal withstanding ability and high cost, so alternative polymeric membranes have been developed with desired properties to overcome this issue. The SPEEK membrane was fabricated with halloysite nanoclay and functionalized graphene oxide (f-GO) nanocomposites at various concentrations via dry phase inversion. The sulfonic acid group in the SPEEK and silane functionalization of GO enhanced the Ion exchange capacity from 0.22 to 0.35 meq/g which enhances the proton conductivity. Furthermore, the thermal stability and hydrophilicity of the pristine SPEEK membrane were reformed with addition of halloysite nanoclay and f-GO in SPEEK membrane. The presence of nanocomposite on the surface of the SPEEK membranes was confirmed via scanning electron microscope (SEM) analysis. The 3 wt% halloysite nanoclay and 2 wt% of f-GO composite membrane was hold the 0.47 mS cm−1 of proton conductivity and 72.2 mW cm−2 of power density, whereas pristine SPEEK membrane was 0.31 mS cm−1 and 28 mW cm−2, respectively. The 3 wt% halloysite incorporated SPEEK membrane and 1.5 wt% f-GO incorporated SPEEK membrane was shown better proton conductivity, which act as a prominent membrane for direct methanol fuel cell (DMFC) applications. [ABSTRACT FROM AUTHOR]

A comprehensive overview of various modifications carried out on polymeric membranes for biomedical applications has been presented in this review paper. In particular, different methods of carrying out these modifications have been discussed. The uniqueness of the review lies in the sense that it discusses the surface modification techniques traversing the timeline from traditionally well-established technologies to emerging new techniques, thus giving an intuitive understanding of the evolution of surface modification techniques over time. A critical comparison of the advantages and pitfalls of commonly used traditional and emerging surface modification techniques have been discussed. The paper also highlights the tuning of specific properties of polymeric membranes that are critical for their increased applications in the biomedical industry specifically in drug delivery, along with current challenges faced and where the future potential of research in the field of surface modification of membranes. • The polymer surface modification methods reviewed. • Compared the surface modification techniques in membrane separation to underlay the current research going in developing new techniques. • The developed materials in combination of surface modification with high potential as tissue replacements, biosensors and antibacterial materials applications. • The tailor made membrane modifications for application in drug delivery and other biomedical applications discussed. [ABSTRACT FROM AUTHOR]