Polyphenylsulfone Research Articles

Microplastics release from infant feeding bottles and milk storage bags

The health impairment of microplastics (MPs) in infants has received considerable attention, with oral ingestion being an important exposure route. However, research remains limited on MPs released in feeding bottles (FBs) and breastmilk storage bottles (BSBs) during daily use. To address this gap, our study investigated the MPs released from polyphenylene sulfone resins (PPSU)-FBs, silicone-FBs, polyethylene (PE)-BSBs, and low-density polyethylene (LDPE)-BSBs under typical usage conditions. Our findings revealed that the four materials of FBs and BSBs can release 1465–5893 particles/L MPs (median concentration). The predominant MPs released from all FBs and PE-BSBs were identified as PE, while LDPE-BSBs predominantly released polyethylene terephthalate (PET) and acrylates (ACR). Approximately 70% of MPs were found within the 20–50 μm particle size range. Higher temperatures led to a two-fold increase in the total MPs. Notably, infants would additionally intake 2080–5910 MPs per day through FBs and BSBs. Months with higher nutritional requirements, and when using silicone FBs and LDPE BSBs, increased the ingestion of MPs in infants. In conclusion, our study highlighted that those FBs and BSBs can precipitate varying numbers, types, and particle sizes of MPs. To protect infants from MPs ingestion, it is recommended to choose non-plastic FBs and non-plastic breastmilk storage containers.

Influence of silver coated zeolite fillers on the chemical and mechanical properties of 3D-printed polyphenylene sulfone restorations

ObjectivesTo investigate the chemical and mechanical properties of polyphenylene sulfone (PPSU) depending on its composition and manufacturing. MethodsUnfilled–PPSU1 and with antimicrobial silver coated zeolites filled–PPSU2 specimens were made of granulate–GR, filament–FI, or printed–3D. Scanning microscopy and X-ray spectroscopy were performed. Martens hardness–HM, elastic indentation modulus–EIT and flexural strength–FS were determined initially and after aging. Shear bond strength–SBS to veneering and luting composite after conditioning with 7 adhesive systems were examined after aging. Silver leaching was tested after 1-, 3-, 7-, 14-, 21-, 28- and 42 days. Analyses of variance, Kolmogorov–Smirnov, Kruskal–Wallis, Mann–Whitney U, unpaired t-tests and Weibull modulus were computed (p < 0.05). ResultsZeolites were homogeneously distributed. PPSU1-GR and PPSU1-FI showed the highest HM/EIT, followed by PPSU2-GR, PPSU1-3D and PPSU2-3D. PPSU2-FI presented the lowest HM/EIT, displaying micro pits. Aging showed reduced HM/EIT in PPSU1 and no impact on PPSU2, while FS increased (PPSU1) or decreased (PPSU2). PPSU2-3D presented lower FS than PPSU1-3D. High SBS to the luting (7.0–16.2 MPa) and veneering composite (11.8–22.2 MPa), except for adhesive system PR, were observed. PPSU2-3D showed the highest silver release (9.6%), with all compositions dispensing silver over 42 days. ConclusionsFor the examined period of 6 weeks, antimicrobial silver ions were released from filled PPSU. The high SBS between PPSU and veneering/luting composite confirmed the feasibility of esthetically veneering and luting filled PPSU. To achieve mechanical properties like unfilled PPSU, the processing parameters of filled PPSU require refinement. Clinical significanceThis investigation provides proof of principle that PPSU can be successfully doped with silver-coated zeolites. The combination of 3D-printing with an antimicrobial thermoplastic constitutes a great opportunity in the field of prosthetic dentistry. Potential applications include clasps for removable dental prostheses, provisional or permanent fixed dental prostheses and implant abutments.

Concentration and Characterisation with Spectroscopic Technique of Microplastics in the Surface Sediment and Commercial Fish Species of Gemlik Bay (Marmara Sea)

In this study, we aimed to evaluate and characterise the microplastic pollution in the sediment and commercial fish species in the Gemlik Bay, the Marmara Sea. Our results showed that the highest concentration of microplastics in the sediment was at the station in the Gemport Harbour (9.73 pieces.kg-1) and the lowest concentration was at the Kurşunlu offshore (3.33 pieces.kg-1). The highest microplastic concentration per individual was in the gills of Synapturichthys kleinii (Risso, 1827) (14.5 pieces.ind-1) and the lowest in Diplodus annularis (Linnaeus, 1758) (0.33 pieces.ind-1). The highest concentration (8.75 pieces.ind-1) was indicated in the gastrointestinal tract of Chelidonichthys lucerna (Linnaeus, 1758), but the lowest concentration (0.88 pieces.ind-1) was in that of D. annularis species. The fiber-type particles were the most determined microplastics in both the sediment and fish samples. The Micro-Raman Spectrometer revealed that Polyvinyl chloride and polypropylene were dominant in the sediment, and polyoxymethylene and polyphenylene sulfone polymers were dominant in fish species.

Antifouling polyphenylene sulfone tight-ultrafiltration membrane by co-depositing dopamine and zwitterionic polymer for efficient dye/salt separation

The exceptional hydrophilicity and charge equilibrium of zwitterionic polymers render them highly desirable as antifouling materials. In this study, a novel zwitterionic copolymer Poly(2-aminoethyl methacrylate-Ethyl acrylatesulfopropyl piperidine salt) [P(AE-EA)] was successfully synthesized. Subsequently, a novel tight-ultrafiltration (t-UF) antifouling membrane employed for dye/salt separation was fabricated by co-depositing dopamine (DA) and P(AE-EA) onto the polyphenylene sulfone (PPSU) membrane substrate. The polydopamine (PDA) and P(AE-EA) are covalently linked through the formation of a covalent bond via Michael addition and Schiff base reactions. By regulating the ratio of PDA and P(AE-EA), the optimized membrane shows a denser and hydrophilic selective layer. The composition and characteristics of the membrane are investigated by serial characterization. The electrostatic adsorption between the membrane surface and the pollutant can be effectively weakened by the incorporation of a zwitterionic polymer P(AE-EA) with neutral charged and hydrophilicity. The modified membrane demonstrates exceptional antifouling performance for BSA, high rejection towards both negatively and positively charged dyes (Congo red, Methylene blue, Methyl orange and Rhodamine B), as well as efficient salt permeance for NaCl, Na2SO4, MgCl2, Mg2SO4 in comparison to that of the pure PPSU membrane. The results presented herein demonstrate the remarkable potential of the novel zwitterionic t-UF membrane for effectively separating dye/salt mixture solutions in the textile industry.

Highly Permeable Ultrafiltration Membranes Based on Polyphenylene Sulfone with Cardo Fragments.

For the first time, copolymers of polyphenylene sulfone (PPSU) with cardo fragments of phenolphthalein (PP) were synthesized to develop highly permeable flat-sheet ultrafiltration membranes. By introducing cardo fragments into the polymer chain, we achieved a mechanical strength 1.3 times higher than the strength of commercial PPSU. It is shown that the introduction of the cardo monomer significantly increases the solubility of the polymer in aprotic solvents. The highest solubility is observed at the concentration of PP 50 mol.%. It is found that reduced viscosity of cardo polymer solutions leads to an increase in the coagulation rate. The permeance of asymmetric ultrafiltration membranes increases with PP concentration from 17.5 L/(m2·h·bar) (10 mol.% PP) to 85.2 L/(m2·h·bar) (90 mol.% PP). These data are in agreement with the results of a study of the coagulation rate of polymer solutions. Thus, for ultrafiltration membranes with 1.5-8 times higher permeance in comparison with PPSU due to the introduction of cardo fragments in the polymer chain, possessing high rejection of the model dye Blue Dextran (MW = 70,000 g/mol), more than 99.2%, as well as high strength characteristics, were achieved.

Influence of two-phase structure of PET/PPSU alloys and selective distribution of flame retardants on the flame retardancy of polymer alloys

Polymer alloys can obtain the excellent performance of a variety of polymers. The polymer blending system has been studied by many scholars, especially the multi-component system containing additives, which is receiving more and more attention from researchers. The flame retardancy behavior of polyethylene terephthalate (PET)/Polyphenylene sulfone (PPSU) blends containing A 9,10-dihydro-9-oxa-10 phosphophenanthrene-10-oxide based derivative tris-(3-dopo-propyl) -triazine trione (TAD) is explored. Flame retardancy of PET/PPSU composite was characterized by Limiting oxygen index (LOI), vertical combustion test (UL 94), and cone calorimeter test. PPSU is a less flammable material with an LOI value of 40.0 % when used alone. With a 5 % flame retardant TAD addition, the LOI value of the PPSU/TAD-5 composite can be increased to 42.6 %. Interestingly, the LOI of PET with 5 wt% of TAD was 30.2 %, whereas the LOI of PET/PPSU(70/30) composites with the same 5 wt% of TAD was reduced to 26.3 %. We investigated by SEM-EDS that the flame retardant TAD always preferred to be distributed in the PPSU phase in PET/PPSU composites with different ratios. When PPSU was wrapped by the PET phase, which is the sea structure, the flame tended to follow the sea structure combustion channel of the polymer alloys during combustion, and the island structure of PPSU had little effect on the overall flame retardancy of the polymer alloys. Similarly, when PPSU becomes a continuous matrix, even without flame retardant, it significantly reduces the combustibility of the blends. However, with the addition of flame retardants, most of the flame retardants are distributed in the PPSU matrix, which significantly increases the LOI value of the PET/PPSU(40/60)/TAD-5 composite. Therefore, we conclude that there is an uneven distribution of flame retardants in the two phases, so for polymer alloys, the distribution of flame retardant in the two phases, as well as the construction of the continuous phase and the dispersion phase, determine the overall flame retardant properties of the composites.

NH2-CAU-1 modified polyphenylene sulfone (PPSU) membrane for separation of oil-in-water emulsions

NH2-CAU-1 modified polyphenylene sulfone (PPSU) membrane for separation of oil-in-water emulsions

Energy-Efficient Nanostructured Ion Exchange Membranes from Functionalized Poly (2,6-Dimethyl-1,4-Phenylene Oxide)

Highly energy efficient and ion permeable ion exchange membranes are in high demand in many modern sectors to clean water, transform energy, and store energy in devices like electro-dialyzer, fuel cells, and batteries. However, greater resistance and reduction in ion permeation of conventional membranes dictate the desire for nanostructured functional ion exchange membranes. This project proposes the fabrication of ion exchange membranes using electroactive nanostructured polyaniline incorporation into ion exchange materials, electrostatically interaction between polymer and nanostructured electroactive material overcomes the problem of high resistance and less ion permeation. Solution casting and post-drying techniques are used for membrane casting. Nanostructured electroactive material helps to increase ionic conduction thus reducing 17% resistance for functional cation exchange membrane (FCEM) and 12% for functional anion exchange membrane (FAEM) also assisting to increase ion permeation. Hydrophilic nanostructured polyaniline electroactive material holds more water and increases water uptake. Cross-linking increases stability as well as reduces 17% and 8% swelling degrees for FCEM and FAEM respectively. Besides the electrochemical property offers an increase limiting current density of 38%, 23% for FCEM and FAEM respectively, and 19% higher desalination performance than non-nanostructured sulfonated polyphenylene oxide (CEM) and quaternized polyphenylene oxide (AEM) membranes.

Casting Electrodes on PEEK Reinforced Sulfonated Polyphenylsulfone Membrane

Researchers are exploring the potential of proton exchange membranes made from hydrocarbon polymers that do not contain fluorine. These polymers possess desirable properties that could make them more environmentally friendly and cost-effective compared to current perfluorinated sulfonic acids (PFSA). Hydrocarbon polymers have a unique structure that maintains high proton conductivity while reducing gas crossover, thus presenting a promising alternative to PFSA membranes [1]. Previous studies have demonstrated the potential of hydrocarbon membranes in electrolyzers using sulfonated polyphenylene sulfone (sPPS) [2]. However, sPPS has a high ion exchange capacity (2.17 – 3.57 meq/g), leading to excessive water uptake that causes the membrane to swelling and impedes upscaling, such as casting anodes directly onto the membrane. To overcome this issue, a woven, open-mesh PEEK substrate was incorporated into the membrane. The reinforced membrane exhibited a significant reduction in water uptake of up to 53% at room temperature and 43% at 60°C compared to the initial membrane. This improvement made it possible to cast the anode directly onto the membrane, resulting in a homogeneous surface (Fig. 1 left). In addition, preliminary electrolysis tests showed promising performance with low membrane resistance of 69 mΩcm² for a 74 µm thick membrane (Fig. 1 right). Literature: [1] Miyake, J.; Taki, R.; Mochizuki, T.; Shimizu, R.; Akiyama, R.; Uchida, M.; Miyatake, K. Design of flexible polyphenylene proton-conducting membrane for next-generation fuel cells. Sci. Adv. 2017, 3(10), eaao0476. DOI: 10.1126/sciadv.aao0476[2] Klose, C.; Saatkamp, T.; Münchinger, A.; Bohn, L.; Titvinidze, G.; Breitwieser, M.; Kreuer, K.; Vierrath, S. All‐Hydrocarbon MEA for PEM Water Electrolysis Combining Low Hydrogen Crossover and High Efficiency. Adv. Energy Mater. 2020, 10 (14), 1903995. DOI: 10.1002/aenm.201903995 Figure 1

Enhancement of the Fracture Toughness of Carbon-Reinforced Plastics by Introducing a Thermoplastic Phase into an Epoxy Matrix

The effect of modifying additives of polyphenylene sulfone or a nonwoven polyamide material on the thermal and mechanical properties of carbon fabric/epoxy resin polymer composite materials prepared by vacuum forming and vacuum infusion was studied. The addition of 10 wt % polyphenylene sulfone leads to slight improvement of the mechanical properties of the composite material, whereas introduction of the nonwoven material leads to a 15% decrease in the compression strength and to a 6% decrease in the interlayer shear strength. The specific peel work increases by 15 and 270% for the composites modified with polyphenylene sulfone and nonwoven cloth, respectively. Introduction of 4 wt % nonwoven material enhances the fracture toughness of the polymer composite material by a factor of 3.7.

Fabrication and characterization of hydrophobic/hydrophilic dual-layer polyphenyl sulfone Janus membrane for application in direct contact membrane distillation

In this study, single-layer (SL) and dual-layer (DL) polyphenyl sulfone (PPSU) flat sheet nanocomposite Janus membranes were fabricated via a combination of VIPS and NIPS techniques for direct contact membrane distillation (DCMD) for the first time. Hydrophobic silica nanoparticles (SiNP-B) were incorporated into the SL membranes and the top layer of the DL membranes, while hydrophilic silica nanoparticles (SiNP-L) were added into the down layer of the DL membranes. The effect of the SiNP-B concentration (1–5 wt%) and the top layer thickness (50 and 100 μm) on the morphology, mean pore size (MPS), thickness, porosity, surface roughness, water contact angle (WCA), liquid entry pressure, mechanical strength, and thermal conductivity were investigated. All of the membranes showed a finger-like structure surrounded by a sponge-like structure. The membranes were examined in the DCMD of a 35,000 ppm saline solution at different feed temperatures (50–70 °C) and flow rates (250–1000 mL/min). The DL membranes possessed higher fluxes than the SL membranes through increasing MPS and WCA. The DL membrane with a SiNP-B concentration of 2 wt% and a hydrophobic thickness of 50 μm (DL- 2,50) achieved the highest flux (42.68 ± 0.35 kg/m2h) and salt rejection (94.90 %) during 5 h. This membrane has an MPS of 0.22 ± 0.03 μm, a thickness of 201 ± 4 μm, and a porosity of 76 ± 2 %. It could be concluded the proper pore size distribution is the most important factor in achieving a successful DCMD operation.

Gas foaming of polyphenyl sulfone: Effect of the blowing agents and operating parameters

AbstractPolyphenyl sulfone (PPSU) is a highly stable and rigid polymer with good chemical and mechanical resistance used in automotive and aerospace industries in high‐temperature applications during long‐operating cycles. PPSU foams are applied as core materials in lightweight composites ensuring high strength, fire resistance, thermal and acoustic insulation. In this paper, PPSU slabs are foamed using CO2, N2, and He as blowing agents (BAs). An experimental campaign is carried out to estimate the BAs' diffusivity in the polymer. In details, CO2 diffusivity ranges from 8E‐11 to 1E‐09 m2/s at temperatures from 220 to 260°C; diffusivity of N2 ranges from 2E‐10 to 5E‐09 m2/s (220–260°C) and it is 4E‐09 m2/s for He at 220°C. Foaming tests reveal an expansion ratio as high as 400% for CO2, 130% for He, and 150% for N2.Scanning electron microscopy analysis is also performed on produced samples, obtaining a cell number density of 1.3E07, 2.6E05, and 1.8E06 cells/cm3 when saturating, respectively, with CO2 at 220°C and 100 bar, N2 at 220°C and 100 bar, and He at 230°C and 100 bar.

Poly(ionic liquid) blended polyphenylene sulfone ultrafiltration membranes with enhanced surface hydrophilicity and antifouling performance

Membrane fouling is a key challenge in the process of utilizing polyphenylene sulfone(PPSU) ultrafiltration (UF) membranes. To address this issue, an amino-functionalized poly(ionic liquid), poly(1-vinyl-3-propylamine imidazolium bis(trifluoromethane sulfonyl) imide) (PIL[TFSI]), was synthesized via free radical polymerization and incorporated into the prepared UF membranes-based PPSU with nanochannels through nonsolvent induced phase separation method. 1H NMR, ATR-FTIR, XPS and EDS spectra verified the introduction of PIL[TFSI]. The AFM and SEM images showed the membrane possessed a classical asymmetrical structure, featuring a higher surface roughness and dense cortex with pits. The decreased water contact angle by the incorporation of PIL[TFSI] indicates the formation of an improved hydrophilic membrane surface. The hydrophilicity of the blended membranes was enhanced by the increasing incorporation of PIL[TFSI]. Meanwhile, the flux decreased slightly, but the selectivity improved significantly. The PIL[TFSI]/PPSU UF membrane with 5% PIL[TFSI] maintained a flux (275 L/m2 h) and a high rejection for bovine serum albumin (BSA) (>99.9%). Additionally, the blended membrane has a superior removal performance for Congo red (>99.9%) and Evans blue (>99.9%). More importantly, the PIL[TFSI]/PPSU UF membranes present excellent antifouling with an increased flux recovery rate from 60.2% to 91.1%. Furthermore, the existence of hydrogen bonds and π-π interactions between PIL[TFSI] and PPSU is conducive to the good stability and sustained hydrophilicity of blended membrane even after continuous immersion for a month.

Simulation and Characterization of Nanoplastic Dissolution under Different Food Consumption Scenarios.

Understanding of the potential leaching of plastic particles, particularly nanoplastics (NPs), from food packaging is crucial in assessing the safety of the packaging materials. Therefore, the objective of this study was to investigate potential exposure risks by simulating the release of NPs from various plastic packaging materials, including polypropylene (PP), general casting polypropylene (GCPP) or metalized casting polypropylene (MCPP), polyethylene (PE), polyethylene terephthalate (PET), and polyphenylene sulfone (PPSU), under corresponding food consumption scenarios. Surface-enhanced Raman scattering (SERS) and scanning electron microscopy (SEM) were utilized to identify and characterize the NPs leached from plastic packaging. The presence of separated NPs was observed in PP groups subjected to 100 °C hot water, GCPP plastic sterilized at a high temperature (121 °C), and PE plastic soaked in 100 °C hot water, exhibited a distorted morphology and susceptibility to aggregation. The findings suggest that the frequent consumption of takeaway food, hot beverages served in disposable paper cups, and foods packaged with GCPP materials may elevate the risk of ingestion of NPs. This reminds us that food packaging can serve as an important avenue for human exposure to NPs, and the results can offer valuable insights for food safety management and the development of food packaging materials.

Effect of Solvent and Monomer Ratio on the Properties of Polyphenylene Sulphone.

For the first time, the effect of the solvent and monomer ratio on molecular weight, chemical structure, and mechanical, thermal, and rheological characteristics of polyphenylene sulfone has been studied. When dimethylsulfoxide (DMSO) is used as a solvent, cross-linking occurs during the processing of the polymer, which is accompanied by an increase in melt viscosity. This fact sets a pressing need for the complete removal of DMSO from the polymer. The best solvent used for the production of PPSU is N,N-dimethylacetamide. This study of the molecular weight characteristics of polymers by gel permeation chromatography showed the stability of the polymers practically does not change with a decrease in molecular weight. The synthesized polymers correspond in tensile modulus to the commercial analog Ultrason-P, while exceeding it in terms of tensile strength and relative elongation at break. Thus, the developed polymers are promising for spinning hollow fiber membranes with a thin selective layer.

Fracture Load of Veneered and Monolithic Single-Unit Fixed Dental Prostheses Made from the High-Performance Thermoplastic Polyphenylene Sulfone

To investigate the fracture load of different veneers for monolithic single-unit fixed dental prostheses (FDPs) made of a novel potential framework material, polyphenylene sulfone (PPSU). The fracture loads of four PPSU frameworks with different veneers (manual polymer veneer with Ceramage Body A3B; prefabricated polymer veneer with Novo.lign; digital polymer veneer with Telio CAD; digital ceramic veneer with IPS Empress CAD) and a monolithic control group (PPSU, Gehr) were examined initially and after 1,200,000 masticatory (50 N, 1.3 Hz) and 6,000 thermal cycles (5°C/55°C). Fracture analysis was performed using light microscope imaging. Fracture types were classified, and relative frequencies were determined. Univariate analysis of variance, post hoc Scheffé, partial eta squared, Kruskal-Wallis test, and Weibull moduli using the maximum likelihood estimation method were calculated. The defined level of significance was adjusted by Bonferroni correction (P < .005). Aging did not affect the fracture load values. Single-unit FDPs with a digital ceramic veneer showed lower values than monolithic and manual polymer-veneer specimens. Single-unit FDPs with a prefabricated and digital polymer veneer were in the same value range as specimens with a manual polymer and digital ceramic veneer. No differences were observed between manual polymer veneer and monolithic single-unit FDPs. All veneered specimens showed a fracture of the veneer. For monolithic single-unit FDPs, a plastic deformation was observed. Veneered and monolithic PPSU showed sufficient fracture load values to indicate successful clinical use in single-unit FDPs. The choice of veneering method and material may play a minor role.

Discussion of “Practical transitions among undrained shear strengths of remolded samples from pocket penetrometer tests and other laboratory tests” by Budak T.O., Gurbuz A. and Eksioglu B. [Catena 213 (2022) 106148

This article presents an appraisal of the recently published research paper in the Catena Journal titled “Practical transitions among undrained shear strengths of remolded samples from pocket penetrometer tests and other laboratory tests”. This paper investigated correlations on undrained shear strength (su) with liquidity index (IL) among pocket (soil) penetrometer (PP), fall-cone, laboratory vane, unconfined compression (UC), and unconsolidated-undrained triaxial compression test methods for 10 fine-grained soils investigated. Some differences between the mobilized su for testing of identically prepared samples of a given soil using different strength measurement approaches could be expected. However, the data plots presented in the original paper indicate that, depending on the IL, significantly different su values can be mobilized among several of these strength tests for a given water content — an aspect that merits critical examination. In this discussion of said paper, several observations are presented on various shortcomings in the adopted experimental methods, as reported in the original paper, and in the su – IL data analyses presented for the different strength tests investigated. Also, with the spring-operated piston of the PP device usually calibrated (by the manufacturer) using correlation studies with UC strength data, the good agreement obtained for the Authors’ PP and UC su – IL correlations would be expected.

When Bulk Matters: Disentanglement of the Role of Polyelectrolyte/Surfactant Complexes at Surfaces and in the Bulk of Foam Films

Foam films display exciting systems as on one hand they dictate the performance of macroscopic foams and on the other hand they allow studies of surface forces. With regard to surface forces, we attempt to disentangle the effect of the foam film surfaces and the foam film bulk. For that, we study the influence of salt (LiBr) on foam films formed by mixtures of oppositely charged polyelectrolyte and surfactant: anionic monosulfonated polyphenylene sulfone (sPSO2-220) and cationic tetradecyltrimethylammonium bromide (C14TAB). Adding a small amount of salt (≤10-3 M) decreases the foam film stability due to a weakened electrostatic net repulsion. In contrast, a large amount of salt (10-2 M) unexpectedly increases the foam film stability. Disjoining pressure isotherms reveal that the increased stability is due to an additional steric stabilization, which is attributed to sPSO2-220/C14TAB complexes in the film bulk. These bulk complexes also contribute to the measured apparent surface potential between the two air/water interfaces. We find, for the first time, the formation of Newton black films for mixtures of anionic polyelectrolytes and cationic surfactants.

Effect of Composition and Viscosity of Spinning Solution on Ultrafiltration Properties of Polyphenylene Sulfone Hollow-Fiber Membranes.

In this work, PPSUs with different molecular weights were synthesized for the development of highly permeable ultrafiltration hollow fiber membranes for the first time. The MW of the synthesized polymers was controlled by varying the monomers molar ratio within 1:1-1.15 under the same synthesis conditions. Based on the study of the rheological properties of polymer solutions, a high molecular weight PPSU (MW 102,000 g/mol) was chosen for the formation of hollow fiber membranes. The addition of PEG400 to the spinning solution led to an increase in viscosity, which makes it possible to work in the region of lower PPSU concentrations (18-20 wt. %) and to form membranes with a less dense porous structure. With the addition of PEG400 to the spinning solution, the membrane permeance increased sharply by more than two orders of magnitude (from 0.2 to 96 L/m2 h bar). At the same time, the membranes had high rejection coefficients (99.9%) of Blue Dextran model filtered substance (MW = 69,000 g/mol).

A homogeneous and mechanically stable artificial diffusion layer using rigid-flexible hybrid polymer for high-performance lithium metal batteries

Artificial solid electrolyte interphase (SEI) is promising to inhibit uncontrollable lithium dendrites and enable long cycling stability for lithium metal batteries. However, the essential mechanical stability is limited since organic layers generally have low modulus whereas intrinsic brittleness for inorganic ones remains a great concern. Polymer-based SEIs with rigid and flexible chains in adequate mechanical properties are supposed to address this issue. Herein, a homogeneous and mechanically stable diffusion layer is achieved by blending rigid chains of polyphenylene sulfone (PPSU) with flexible chains of poly (vinylidene fluoride) (PVDF) in a hybrid membrane, enabling uniform diffusion and stabilizing the lithium metal anode. The Li||Cu cell with the protected electrode exhibits a long lifetime more than 450 cycles (0.5 mA cm−2, 1.0 mA h cm−2) (fourfold longer than the control group) with higher average Coulombic efficiency of 98.7%. Enhanced performances are also observed at Li||Li and full cell configurations. The improved performances are attributed to the controlled morphology and stable interphase, according to scanning electron microscopy (SEM) and electrochemical impedance. This research advances the idea of uniform lithium plating and provides a new insight on how to create a homogeneous and mechanically stable diffusion layer using rigid-flexible polymers.