Phase Inversion Technique Research Articles

Improved properties and salt rejection of polysulfone membrane by incorporation of hydrophilic cobalt-doped ZnO nanoparticles

In this study, the nanoparticles (NPs) of ZnO and Co2+ ions doped ZnO (doped ZnO) were incorporated into a matrix of polysulfone (PSf) membranes to enhance their surface properties prepared using a simple wet phase inversion technique. The hybrid PSf membranes were fabricated with 0.5 wt. % of ZnO and doped ZnO NPs. These membranes were characterized using XRD, TGA, FESEM-EDX, and salt rejection performance. The hydrophilicity of PSf membranes was improved by adding of ZnO and doped ZnO NPs which showed a decrease in contact angle values from 82° to 62° with an increased flux with water. Among the prepared membranes, doped ZnO NPs showed the highest salt rejection for both sodium chloride (NaCl) and sodium sulfate (Na2SO4) compared to pure PSf and PSf with ZnO NPs which confirm the improvement contact angle and water permeability. Overall, the results of this study showed that embedding a small amount of Co2+ ions doped ZnO NPs with PSf has significant potential to be applied in industrial-scale membrane applications.

Surface modification of GO/PVDF composite membrane by MXene/protonated g‐C₃N₄ nanosheets hybrids with improved dye separation and antifouling properties

AbstractGraphene oxide‐polyvinylidene composite membranes were fabricated via the phase inversion technique. Then, GO‐PVDF membrane with highest water flux was achieved via surface modification with 2‐D MXene and 2‐D MXene /protonated 2‐D g‐C₃N₄ nanosheets hybrid via vacuum filtration of an aqueous dispersion of MXene and MXene‐protonated g‐C₃N₄ nanosheets hybrid, respectively, on GO‐PVDF membrane support to improve filtration efficiency and antifouling properties. The membranes were designated as MXene/GO‐PVDF (M2) and MXene‐protonated g‐C₃N₄/GO‐PVDF(M3). XRD, SEM, and FTIR analysis were used for characterization. The results showed that the performance of both MXene /GO‐PVDF and MXene‐ Pg‐C₃N₄/GO‐PVDF membranes was improved significantly in removing cationic dyes, unlike anionic pigments. Also, the resistance of these membranes against fouling has improved. The MXene‐ Pg‐C₃N₄/GO‐PVDF shows a significant enhancement in the removal of crystal violet (CV) cationic dye (100%) compared to the pristine membrane (84%) after 4 h of the filtration process. Tests also were performed to remove another two cationic dyes Methylene blue (MB), Rhodamine B (RB), and an anionic dye Methyl‐orange. The anionic dye separation rate from the stream did not show significant improvement while cationic dyes show significant enhancement in separation efficiencies. Modified membranes exhibit an enhancement of fouling resistance properties compared to pristine membranes.Highlights The water contact angle decreased from 71 to 45, which means hydrophilicity improved successfully. Membrane fouling resistance was improved around 15%–20%. PVDF membrane was prepared and graphene oxide was added to the matrix to modify the bulk properties. MXene and C3N4 were synthesized successfully. Surface modification of the PVDF membrane was successful by MXene and C3N4.

Polyamide 66 hybrid TiO2–pectin flat-sheet membrane applied to wetland water ultrafiltration

This article describes a study in which a hybrid, polyamide 66 flat-sheet membrane is fabricated and then used to eliminate turbidity in wetland water in an area of South Kalimantan, Indonesia. The membrane was prepared by the phase inversion technique, using nylon 66, formic acid solvent, titanium dioxide and pectin as additives. Results show that the pure water flux of the membrane produced is extremely high – reaching 418.04 Lm-2h-1 – but decreased to 311.97 Lm-2h-1 with the addition of TiO2–pectin. When applied to wetland water the PA–TiO2–pectin membrane showed 100% turbidity rejection.

Immobilization of carbonic anhydrase on modified PES membranes for artificial lungs.

The introduction of carbonic anhydrase (CA) onto an extracorporeal membrane oxygenation (ECMO) membrane can improve the permeability of carbon dioxide (CO2). However, existing CA-grafting methods have limitations, and the hemocompatibility of current substrate membranes of commercial ECMO is not satisfactory. In this study, a 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC)/N-hydroxy succinimide (NHS) activation method is adopted to graft CA with CO2-catalyzed conversion activity onto a polyethersulfone (PES) membrane, which is prepared by a phase inversion technique after in situ crosslinking polymerization of 1-vinyl-2-pyrrolidone (VP) and acrylic acid (AA) in PES solution. The characterization results reveal that CA has been grafted onto the modified PES membrane successfully and exhibits catalytic activity. The kinetic parameters of esterase activity verify that the grafted amount of active CA increases with an increase in the concentration of the CA incubation solution. The CA-grafted membrane (CA-M) can accelerate the conversion of bicarbonate to CO2 in water and blood, which demonstrates the special catalytic activity towards bicarbonate of CA. Finally, blood compatibility tests prove that the CA-M does not lead to hemolysis, shows suppressed protein adsorption and increased coagulation time, and is suitable for application in ECMO. This work demonstrates a green and efficient method for preparing bioactive materials and has practical guiding significance for subsequent pulmonary membrane research and ECMO applications.

Pterostilbene lipid nanocapsules as a promising system for treatment of hepatocellular carcinoma: Formulation, characterization, and cellular/in vivo appraisal

Pterostilbene has shown very promising traits as a nutraceutical compound, especially in the field of cancer treatment. However, its poor aqueous solubility hinders its clinical applicability. The purpose of this work was to enhance the antitumoral activity of pterostilbene in hepatic cancer via encapsulation in lipid nanocapsules. Pterostilbene nanocapsules were prepared using the phase inversion technique. One gram of Kolliphor® HS 15 dissolved in 3 g of distilled water was added to 1 g of isopropyl myristate containing 150 mg Epikuron 200 and 100 mg pterostilbene under magnetic stirring, while applying three temperature cycles alternating between 55 and 85 °C for phase inversion to occur. Shock cooling of the dispersion was induced by introduction of 5 g of distilled water, followed by stirring for 30 min. The nanocapsules were characterized for the particle size, polydispersity index, zeta potential, entrapment efficiency, drug loading, morphology, antitumoral activity in HepG2 liver cancer cell line in terms of viability, assessment of cell death mode and cycle arrest, cellular localization assessment, and quantification of cellular uptake. The in vivo antitumoral activity of lipid nanocapsules was further verified using a chemically-induced hepatic cancer model using diethylnitrosamine and carbon tetrachloride. Several biochemical markers were quantified, followed by histopathological examination. Results displayed the potential of pterostilbene in treatment of liver cancer, with the enhancement of its therapeutic efficacy by encapsulation in lipid nanocapsules, as evidenced by further decreased levels of ALT, AST, AFP, Bcl2, VEGF, NF-kB, ERK, AKT, with concomitant increase in caspase3 level, while showing comparable histological features to the normal control group. Pterostilbene nanocapsules were proven promising in the treatment of hepatocellular carcinoma, deserving further preclinical and clinical evaluation.

MIL-101(Cr) incorporated hollow fiber membrane for rubber wastewater treatment using membrane bioreactor

The hollow fiber (HF) membrane in this study was modified using polyethersulfone (PES) and MIL-101(Cr) metal–organic framework (MOF) for the treatment of synthetic rubber effluent using an aerobic submerged membrane bioreactor (MBR). The phase inversion and wet spinning techniques were used for membrane preparation and to manufacture the MOF-incorporated HF membranes, respectively. The manufactured HF membranes were characterized using Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR-KBR), Atomic Force Microscopy (AFM), X-Ray Diffraction (XRD), Tensile Strength (TS), and Water Contact Angle (WCA) studies. The MIL-101(Cr)/PES HF membrane has increased porosity by 14%, surface roughness increased by 38%, and surface hydrophilicity increased by 15% compared to the pure PES HF membrane. The results demonstrated that the higher hydrophilicity of the metal–organic framework (MOF) MIL-101(Cr) positively affected the HF membrane surface properties and performance in the bioreactor. Additionally, it was shown that the removal efficiency for total suspended solids (TSS), total dissolved solids (TDS), biological oxygen demand (BOD5), and chemical oxygen demand (COD) were 45.5%, 65.6%, 90%, and 94% respectively.

PEBAX polymer inclusion hydrophobic deep eutectic solvent membranes for pervaporation of biobutanol: Mass transfer and COSMO-RS analysis

Deep Eutectic Solvent(DES) and specifically Hydrophobic Deep Eutectic Solvents (HDES) are considered a relatively novel class of solvents, which show good features to include them in pervaporation membranes. Polymer inclusion HDES membranes offer a separation media, which shows a faster molecular diffusion than polymeric membranes, combining the best properties of liquid and polymer membranes, such a high selectivity with high burst pressure and durability.The aim of this work focuses on the development of different PEBAX/ lidocaine-thymol [2:1] (Lidol HDES) membranes by the temperature-induced phase-inversion technique to be used in the pervaporation process to recover butanol from ABE model solution. The mass transfer modeling through the membrane using the resistances-in-series approach was implemented to find the mass transfer resistance distribution.The polymer inclusion membranes showed improved results for the butanol/water selectivity compared to the single PEBAX membrane used as a reference. The flux of butanol obtained with the 30 % w/w Lidol HDES membrane was 0.112 kg m−2 hr−1. The flux of water was 0.445 kg m−2 hr−1 showing a selectivity value for butanol/water of 20 % bigger than single PEBAX membrane. The improvement in the selectivity can be explained by the synergic effect of the HDES in the membrane.After use, the polymer inclusion membrane consistently demonstrated a stable performance in effectively separating butanol from the ABE solution. It was seen that the overall resistance decreases as the liquid flow rate increases; regarding the liquid side resistance, it becomes important at smaller flow rates and is almost negligible for turbulent regimen.

Surface decoration of polyethylene terephthalate (PET) waste bottle-derived ultrafiltration membrane for enhanced lead ion removal and antifouling properties

PET waste bottle can be potentially used to create eco-friendly ultrafiltration (UF) membranes for water and wastewater treatment. The surface modification and functionalization of PET UF membrane offer opportunities to further heighten the performance of the membrane. In this study, phase inversion technique was used to fabricate PET UF membranes and PET/graphene oxide (GO) nanocomposite membranes through a facile GO suspension coating approach. The GO nanosheets were deposited on the PET UF membrane as a wavy and wrinkly layer. Using lead (Pb) ions and bovine serum albumin (BSA) feed solutions, the filtration performances of the neat PET and GO-PET membranes were evaluated. It was observed that, the Pb ions and BSA removal efficiencies were greatly enhanced by the surface decorated GO. Compared to neat PET, the 0.5GO-PET membrane exhibited improved flux performance by 188% and 61% for the removal of Pb ions and BSA, respectively. A high Pb ion removal of 100% and a BSA rejection of 97% were achieved by 0.5GO-PET membrane. The lower fouling tendency of 0.5GO-PET membrane during long-term filtration was attributed to the increased surface hydrophilicity and smoothness upon the deposition of GO layer. This study demonstrates a sustainable solution for efficient water treatment and heavy metal removal.

High performance photodegradation resistant PVA@TiO2/carboxyl-PES self-healing reactive ultrafiltration membrane

The occurrence of ultrafiltration (UF) membrane fouling frequently hampers the sustainable advancement of UF technology. Reactive self-cleaning UF membranes can effectively alleviate the problem of membrane fouling. Nevertheless, the self-cleaning process may accelerate membrane aging. Addressing these concerns, we present an innovative design concept for composite self-healing materials based on self-cleaning UF membranes. To begin, TiO2 nanoparticles were incorporated into the polymer molecular structure via molecular design, resulting in the synthesis of TiO2/carboxyl-polyether sulfone (PES) hybrid materials. Subsequently, the nonsolvent-induced phase inversion technique was employed to prepare a novel of UF membrane. Lastly, a polyvinyl alcohol (PVA) hydrogel coating was applied to the hybrid UF membrane surface to create PVA@TiO2/carboxyl-PES self-healing reactive UF membranes. By establishing a covalent bond, the TiO2 nanoparticles were effectively and uniformly dispersed within the UF membrane, leading to exceptional self-cleaning properties. Furthermore, the water-absorbing and swelling properties of PVA hydrogel, along with its capacity to form hydrogen bonds with water molecules, resulted in UF membranes with improved hydrophilicity and active self-healing abilities. The results demonstrated that the water contact angle of PVA@5%TiO2/carboxyl-PES UF membrane was 43.1°. Following a 1-h exposure to simulated solar exposure, the water flux recovery ratio increased from 48.16% to 81.03%. Moreover, even after undergoing five cycles of 12-h simulated sunlight exposure, the UF membranes exhibited a consistent retention rate of over 97%, thus fully demonstrating their exceptional self-cleaning, antifouling, and self-healing capabilities. We anticipate that the self-healing reactive UF membrane system will serve as a pioneering and comprehensive solution for the self-cleaning antifouling challenges encountered in UF membranes while also effectively mitigating the aging effects of reactive UF membranes.

Comparable investigation for incorporation of zirconium MOF@PVDF membrane as cation selective membranes for lithium-ion separation

To improve the efficiency of lithium-ion separation and removal from contaminated water, the performance of zirconium MOFs as filler for PVDF composite membranes in lithium-ion separation was investigated in this work utilizing the electrodialysis technique. Two different cations selective PVDF-based membranes, UiO-66/PVDF and UiO-66/ZIF-8/PVDF were casted using the phase inversion technique. Various spectroscopic techniques were utilized to validate the physicochemical properties of fabricated PVDF composite membranes, which include FTIR, XRD, SEM, and XPS. It was evident that the fabricated UiO-66/ZIF-8/PVDF membrane exhibits superior lithium-ion removal (94 %) from contaminated water, compared to the UiO-66/PVDF membrane which exhibits 75 % removal at a high Li ion concentration (400 ppm). It was evident that the UiO-66/ZIF-8/PVDF membrane exhibits adsorptive qualities towards Li-ion removal, making it more appropriate for water treatment. In contrast, UiO-66/PVDF showed higher cation migration capabilities, which is encouraging for lithium recovery. These different separation mechanisms of the fabricated PVDF-based composite membranes toward Li ions are owed to the properties and the functionality of MOFs utilized as membrane fillers beside the intercalated pore structure of the fabricated composite membrane that produces ion channels with ion adsorptive characteristics. The promising features of the fabricated composite membranes render them suitable for lithium separation from contaminated water.

Nanomagnets doped antifouling membrane for fine emulsion separation

Reutilizing domestic and industrial wastewater can be the best solution to global water issues. However, the treatment of oily wastewater is a long-standing problem due to the complex fine emulsion produced by mixing the different types of oils and organic solvents. In this work, nanocomposite membranes were fabricated using phase inversion technique by loading polysulfone matrix with varying amounts of magnetic nanoparticles (MNPs). Developed nanocomposite membrane has shown hydrophilic and super-oleophobic properties with an underwater contact angle of 145 ± 3°. Incorporating MNPs into the Psf membranes enhanced the performance and permeability with the oil rejection efficiency as high as ∼99 %. Psf-MNP composite membranes exhibited remarkable antifouling properties, preventing oil deposition on the membrane surface with improved mechanical properties. Our studies suggest that the developed Psf-MNP nanocomposite membrane shows increased surface functionality, which leads to promising long-term performance and reusability of the membrane.

Dual-phase La0.5Sr0.5Fe0.8Co0.2O3−δ-Ce0.8Sm0.2O2-δ hollow fiber membranes for oxygen separation

In this work, the dual-phase La0.5Sr0.5Fe0.8Co0.2O3-δ-Ce0.8Sm0.2O2-δ (LSCF-SDC) (65–35 wt%) hollow fiber membranes were prepared via combined method of phase inversion and sintering technique. In situ X-ray diffraction (XRD) experiments showed that the structure of LSCF-SDC is stable in air and vacuum (pO2 ∼ 10−4 atm) in the temperature range of 30–900 °C. Moreover, the effect of temperature, oxygen partial pressure and surface modification on the oxygen fluxes across LSCF-SDC hollow fiber membranes were studied. The results obtained indicate that the oxygen fluxes through dual-phase LSCF-SDC hollow fiber membranes are limited by surface exchange reactions. LSCF-SDC hollow fiber membranes also demonstrated high resistance to CO2 in short-term stability test.

New insights into single-step fabrication of finger-like anode/electrolyte for high-performance direct carbon solid oxide fuel cells: Experimental and simulation studies

Cell preparation techniques and design parameters have significant impacts on the electrochemical performance of direct carbon solid oxide fuel cells (DC-SOFCs). In this work, a finger-like nickel-based anode/electrolyte has been successfully fabricated in a single step via the tape-casting combined phase-inversion and co-sintering technique, which simplified the preparation process and reduced the fabrication cost. The finger-like anode/electrolyte exhibited identical microstructure and exceptional adhesion, ensuring the absence of any cracks during the co-sintering process. As a result, the corresponding single cell delivered a very competitive output of 436 mW cm−2 at 850 °C using activated carbon as fuel. Moreover, it operated stably for 20.1 h under 100 mA with a high fuel utilization of 22.5% at 850 °C. Model verification was also performed by comparative analysis of the effects of the finger-like pore length, anode thickness, cathode thickness, and electrolyte thickness on the cell performance using numerical simulation, which generated the resultant two-dimensional distributions of CO molar concentration, current density, O2 molar concentration, and temperature as well as the power output of the cell. Simulation results verified the experimental findings that DC-SOFC performance was enhanced with increases in the finger-like pore length and cathode thickness, and with decreases in the anode and electrolyte thicknesses. This work provides valuable insights into further optimizing the cell design and manufacturing process, paving the way for the development of high-performance DC-SOFCs.

Acid mine drainage (AMD) treatment using a novel tannic acid functionalized Boehmite/polyether sulfone nanofiltration membrane

This study focuses on the fabrication of TA-BM/PES membranes by the incorporation of tannic acid functionalized Boehmite nanoparticles into the PES membrane matrix through the phase inversion technique. The presence of TA-BM nanoparticles in the TA-BM/PES membranes was confirmed by analysis of the FT-IR spectra of the embedded membranes. The hydrophilicity, permeability, surface morphology, and fouling resistance properties of membranes modified with TA-BM nanoparticles were compared to those of the naked membrane. The fouling behavior of the modified membranes was assessed in the presence of a foulant solution containing 200 ppm BSA (bovine serum albumin) and 200 ppm Na2SO4. The flux recovery ratio results showed an improvement in all modified membranes, especially M2 membrane. The modified membranes shown remarkable efficiency in the rejection of heavy metal ions (over 72 %), sulfate (over 80 %), and salt (Na2SO4 > 84 % and NaCl>48 %). The M2 membrane was chosen as the most suitable membrane and shown effective performance in eliminating heavy metals (Fe2+ = 65.5, Mn2+ = 88.8, Mg2+ = 83.5 and Ca2+ = 78.6 %) as well as sulfate (SO42− = 83.5 %) from a synthetic acid mine drainage (AMD) wastewater. Based on the findings presented in this research, it can be concluded that the TA-BM/PES nanofiltration membrane has potential for effective use in the treatment of AMD wastewater.

Fabrication and characterization of TiO2/Fe2O3 nanocomposites incorporated on novel ternary polymer blends for effective lead removal

ABSTRACT Polymer membrane plays a vital role in water treatment. Removing heavy metals such as Pb, Cr, Hg, Zn, and Al are the main focus of recent research. The mixed matrix membrane is a current trend with more advantages than the blend membrane. The design of a ternary polymer membrane for the removal of Pb can neglect the drawbacks associated with the single or blend membrane, such as hydrophilicity, flexibility, mechanical strength, and, most significantly, they have better adsorption capacity. Thus, PEI/CS/PU as a ternary polymer blend can show a hydrophilic measurement of 66.5° after incorporating TiO2/Fe2O3 nanocomposites. The significant functional group confirmations, crystallinity, and elemental compositions were confirmed via FTIR, XRD, and XPS after casting the membrane through the phase inversion technique. Also, incorporating nanomaterials has played a vital role in increasing the thermal stability of prepared ternary membranes. Furthermore, the membrane showed a pore diameter of 1.893 m2/g by BET analysis. The significant functional groups such as ether, imide, polyols, hydroxyl groups, and carbohydrates have helped enhance the batch adsorption experiment of TiO2/Fe2O3@PEI/CS/PU. The TiO2/Fe2O3@PEI/CS/PU system is well fitted with Freundlich isotherm at R2 = 0.97577. Hence, TiO2/Fe2O3@PEI/CS/PU membrane can be a potential adsorbent for Pb removal from water sources.

Contribution of zeolitic imidazolate framework-8 in improving the performance of polymer electrolyte membrane for direct methanol fuel cell

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.

Enhancing the hemocompatibility of polyethersulfone (PES) hemodialysis membranes using synthesized pseudo zwittronic polymers with various orientations

The incompatibility of membrane materials with blood in the dialysis process has resulted in extensive number of side effects as well as undesired mortality rates for end-stage renal disease (ESRD) patients. Recent attention has been directed at enhancing the hemocompatibility of dialysis membranes. This study synthesized polyether sulfone (PES) mixed matrix membranes (MMMs) containing modified silica nanoparticles (SiO2 NPs) using the phase inversion technique. SiO2 NPs were modified with pseudo-zwitterionic (pZW) coatings of different structures. The modification of SiO2 NPs and their presence in casted MMMs were confirmed using Fourier-transform infrared (FTIR) spectroscopy. Molecular dynamics (MD) simulations were used to compute the quantity and energy of hydrogen bonds, which serve as a metric of hemocompatibility. Surface charge measurements were used to confirm the neutralization of the modified membrane surface charge. Atomic force microscopy (AFM) analysis revealed the influence of the structure of the SiO2 NPs on casted MMM surface roughness. The influence of the pZW coating structure on MMM hemocompatibility was examined in vitro using patient serum to investigate the inflammatory biomarkers released (C5a, IL-1α, IL-1β, IL-6, properdin, C5b-9). The clinicalex-vivo studies showed improvement of hemocompatibility in terms of IL-1α, IL-1β, Properdin, and C59-9. 5 % lower secretion of complement factor and interleukins reflected an improvement of hemocompatibility. Comparing MMM-1 to the other samples, the hemocompatibility profile was better. MD results were in agreement with the clinical outcomes as MMM-1 had the highest number of hydrogen bonds (8) and hydrogen bonding energy value (0.72 kcal/mol), indicating greater water interaction.

Improvement of Selectivity and Antifouling Properties of Chitosan-modified Polyvinylidene Fluoride (PVDF) Membrane for Protein Filtration

<p>Protein with high purity is currently a valuable commercial commodity, prized for its high value and application in specialized functions. PVDF-based membrane technology has found widespread use in protein purification processes. However, the issue of fouling on the membrane surface frequently hampers the performance of PVDF membranes. The present study aims to enhance PVDF membranes' selectivity and antifouling properties through chitosan modification, thereby optimizing protein filtration. PVDF and PVDF/Chitosan membranes were fabricated using the phase inversion technique, followed by a comprehensive characterization of their surface properties, thermal attributes, and performance in bovine serum albumin (BSA) protein filtration. The collected data revealed notable increases in membrane hydrophilicity, porosity, and pure water flux due to the incorporation of chitosan. The membrane protein rejection capabilities were significantly enhanced to levels exceeding 90% with the introduction of 0.5% chitosan. Moreover, as the chitosan concentration increased, the membrane exhibited superior antifouling characteristics, with the 0.5% chitosan concentration yielding the highest Flux Recovery Ratio (FRR) value of 85.35%. Considering the significant improvement selectivity and antifouling properties in the combined system, the chitosan-modified PVDF membrane holds substantial promise in protein purification applications.</p>

Improvement of Selectivity and Antifouling Properties of Chitosan-modified Polyvinylidene Fluoride (PVDF) Membrane for Protein Filtration

<p>Protein with high purity is currently a valuable commercial commodity, prized for its high value and application in specialized functions. PVDF-based membrane technology has found widespread use in protein purification processes. However, the issue of fouling on the membrane surface frequently hampers the performance of PVDF membranes. The present study aims to enhance PVDF membranes' selectivity and antifouling properties through chitosan modification, thereby optimizing protein filtration. PVDF and PVDF/Chitosan membranes were fabricated using the phase inversion technique, followed by a comprehensive characterization of their surface properties, thermal attributes, and performance in bovine serum albumin (BSA) protein filtration. The collected data revealed notable increases in membrane hydrophilicity, porosity, and pure water flux due to the incorporation of chitosan. The membrane protein rejection capabilities were significantly enhanced to levels exceeding 90% with the introduction of 0.5% chitosan. Moreover, as the chitosan concentration increased, the membrane exhibited superior antifouling characteristics, with the 0.5% chitosan concentration yielding the highest Flux Recovery Ratio (FRR) value of 85.35%. Considering the significant improvement selectivity and antifouling properties in the combined system, the chitosan-modified PVDF membrane holds substantial promise in protein purification applications.</p><p> </p><p><img src="/public/site/images/fitria/rsz_72110.png" alt="" /></p>

Exceptional cyclability of thermally stable PVdF-co-HFP/SiO2 nanocomposite polymer electrolytes for sodium ion batteries

Thermally stable composite polymer electrolyte (CPE) devising PVdF–co–HFP polymer with in–situ generated silica (SiO2) as filler is synthesised via non–solvent– induced phase inversion technique. The filler loading of in–situ synthesised silica in PVdF–co–HFP is varied from 0 to 9 wt% and its morphological, thermal and electrochemical characterization is carried out. Among the different composite electrolytes, the PVdF–co–HFP containing 6 wt% SiO2 shows the uniform microporous structure with a highest porosity (84 %), surface area (784.14 m2 g−1), electrolyte uptake (262 %) and electrolyte retention value (0.48). The incorporation of in–situ SiO2 on CPE shows not only the enhancement in thermal stability but also reduced thermal shrinkage with an increase in the filler content. The electrochemical studies of PVdF–co–HFP containing 6 wt% SiO2 shows a higher ionic conductivity (0.71 mS cm−1) and potential stability >4.5 V verses Na/Na+. The Na–ion half–cells assembled with PVdF–co–HFP/SiO2 composite electrolyte show a specific capacity of ∼120 mAh g−1 at 0.3C rate in room temperature and a stable cycle performance with a Coulombic efficiency of around 100 % for 200 cycles.