PPESK Membranes Research Articles

A high-strength electrospun PPESK fibrous membrane for lithium-ion battery separator

The electrospun fibrous membranes used as lithium-ion battery separators have been widely studied due to the advantages of high porosity, large specific surface area and adjustable structural characteristics. In order to obtain thermal stable and high-strength electrospun fibrous membranes for lithium-ion battery separators, the oriented poly(phthalazinone ether sulfone ketone) (PPESK) fibrous membranes were fabricated and then hot pressed with two pieces of membranes overlaid perpendicularly. The prepared hot-pressed composite oriented PPESK membranes show high tensile strength of 22.8 MPa at both horizontal and vertical directions. The hot-pressed oriented PPESK membranes are thermally dimensional stable even at the high temperature of 200 °C. In addition, the novel PPESK fibrous membranes exhibit high porosity (70%), superior electrolyte uptake (525%), low interfacial resistance (268 Ω) with electrodes and excellent ionic conductivity (1.39 mS cm−1). The simulated cells using the new separators show high discharge capacity and excellent rate capability, which demonstrates the novel membranes have potential to be used as separators for power lithium-ion batteries.

Preparation and evaluation of poly(phthalazinone ether sulfone ketone) ultrafiltration membrane with organic and inorganic nano-TiO2 additives

The effects of additives of nano-TiO2, PEO–PPO–PEO/nano-TiO2, oxalic acid/nano-TiO2, and oxalic acid/PEO–PPO–PEO/nano-TiO2 on PPESK membrane performances and gelation kinetics mechanism were investigated in detail. When the single nano-TiO2 concentration increased from 0.2 to 1.0 wt%, the water flux and the rejection changed slightly at first and then reduced, and the gelation rate was the fastest for 0.6 wt% nano-TiO2. With the PEO–PPO–PEO concentration increasing from 1.0 to 5.0 wt% which contained 0.6 wt% nano-TiO2 in the casting solution, the water flux floated between 368 and 530 L/m2 h at first and then went up significantly to 1109 L/m2 h, the rejection diminished remarkably, and also the gelation rate increased. With the increase in oxalic acid concentration ranging from 1.0 to 3.0 wt% (including 0.6 wt% nano-TiO2 in the casting solution), all the water flux, the rejection, and gelation rate changed mildly. For oxalic acid/PEO–PPO–PEO/nano-TiO2 blend additives, with the oxalic acid concentration increasing from 1.0 to 2.5 wt% consisting 2.0 wt% PEO–PPO–PEO and 0.6 wt% nano-TiO2, the water flux and the rejection remained stable; however, the gelation rate accelerated. All the PPESK membranes in this study exhibited asymmetric finger-like structures.

Preparation and arsenic adsorption assessment of PPESK ultrafiltration membranes with organic/inorganic additives

In this paper, the effects of PPESK concentration, and additives of PEO–PPO–PEO, oxalic acid/PEO–PPO–PEO, nano-TiO2/oxalic acid/PEO–PPO–PEO on membrane performances and arsenic adsorption properties were investigated. Compared with single additive of PEO–PPO–PEO, oxalic acid/PEO–PPO–PEO or nano-TiO2/oxalic acid/PEO–PPO–PEO had better pore-forming ability. It was found that PPESK membranes with additives of PEO–PPO–PEO or oxalic acid/PEO–PPO–PEO had no arsenic adsorption capability. For optimized PPESK membrane (14.0wt.% PPESK/1.2wt.% nano-TiO2/3.0wt.% oxalic acid/3.0wt.% PEO–PPO–PEO), with the contact time increasing, the arsenic adsorption efficiency decreased from 100 to 73.7%; with the increase of operation pressure, the efficiency of arsenic adsorption led a light decrease which ranged from 86.6 to 70.8%; when the arsenic (V) concentration increased from 0ppb to 500ppb, the arsenic adsorption efficiency reduced from 100 to 8.3%; the effect of feed temperature on arsenic adsorption was indistinctively; as the pH increasing from 3 to 11, the efficiency of arsenic adsorption first kept stable at 85.0%, and then decreased to 63.4%.

Preparation of a poly(phthalazine ether sulfone ketone) membrane with propanedioic acid as an additive and the prediction of its structure

ABSTRACTIn this study, propanedioic acid was investigated as a potential additive in poly(phthalazine ether sulfone ketone) (PPESK)/N‐methyl‐2‐pyrrolidone solutions. Compared with poly(ethylene glycol) with a molecular weight of 1000 and Tween 80 as additives, different phenomena were observed: (1) both fingerlike and spongelike structures of asymmetric ultrafiltration membranes were induced by rapid gelation, and (2) a spongelike structure membrane with a high pure water flux was obtained under a high gelation rate. Moreover, the PPESK membrane formation process was recorded with a recently developed optical microscopy (OM)–charge‐coupled device (CCD) camera experimental system. The predicted membrane structure with an OM–CCD system gave good correspondence with the final membrane structure and performance, as detected by scanning electron microscopy. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41621.

Thermostable PPESK/TiO2 nanocomposite ultrafiltration membrane for high temperature condensed water treatment

Poly (phthalazine ether sulfone ketone) (PPESK)/TiO2 organic–inorganic composite ultrafiltration (UF) membranes with enhanced performance for high temperature condensed water treatment were prepared using a phase-inversion method. The effects of TiO2 concentration on the membrane morphologies, physic-chemical properties, membrane permeability and antifouling performance were investigated and discussed. The SEM result reveals that the penetrated finger-like structure in sublayer is suppressed, and sponge-like structure begins to be developed. The mechanical strength and thermal stability of composite membrane are improved due to the existence of hydrogen bond between TiO2 and polymer. The permeate flux is also enlarged due to the improved hydrophilicity and porosity. Compared with neat PPESK membrane, the composite membranes present improved antifouling properties, showing lower filtration resistances, MFI values and better flux recover property during high temperature condensed water treatment. The optimal addition amount of TiO2 is 2wt.%. The high temperature condensed water with excess oil and iron can be treated efficiently using PPESK/TiO2 composite membrane. The turbidity of feed solution is almost removed. The oil and iron concentrations in permeate solution are 0.89mg/L and 26.4μg/L which meet the Quality Criterion of Water and Steam for Steam Power Equipment in China.

Hydrophilic modification of poly(phthalazine ether sulfone ketone) ultrafiltration membranes by the surface immobilization of poly(ethylene glycol) acrylates

Poly(ethylene glycol) acrylates (PEGA) containing double-bond in the molecular chain end were synthesized via the esterification of poly(ethylene glycol) (PEG) with acrylate acid in aid of the catalysis of p-toluenesulfonic acid. Then hydrophilic modification of poly(phthalazine ether sulfone ketone) (PPESK) ultrafiltration membranes was achieved by the surface immobilization of PEGA assisted by UV irradiation. The unmodified and modified membranes were characterized by Fourier transform infrared (FT-IR) spectroscopy, contact angle measurements, protein adsorption, tensile tests, ultrafiltration experiments. The results of water contact angle measurements and static bovine serum albumin (BSA) adsorption tests showed that the immobilization of PEGA afforded PPESK membranes to be more hydrophilic and less susceptible to protein fouling. The tensile strength and the break elongation ratio of the PPESK membrane declined in a small extent after the surface modification due to the cleavage of molecular chains under UV irradiation. From the comparisons of the pure water flux and PEG rejection between the unmodified and modified PPESK membranes, it was suggested that water permeability and solute rejection ratio can be simultaneously promoted when controlling a fitting amount of immobilized PEG acrylates. The modified membranes have a good stability even when swelling in NaClO solution for a long time.

Amphiphilic PPESK- graft-P(PEGMA) copolymer for surface modification of PPESK membranes

Amphiphilic graft copolymer consisting of poly(phthalazinone ether sulfone ketone) (PPESK) backbones and poly-(poly(ethylene glycol) methyl ether methacrylate) (P(PEGMA)) side chains was synthesized by atomic transfer radical polymerization (ATRP). PPESK resin was beforehand chloromethylated, and the obtained chloromethylated PPESK (CMPPESK) containing benzyl chloride groups was used as macro-initiators to graft hydrophilic P(PEGMA) chains. The synthesized products were characterized by 1H NMR, Fourier transform infrared (FT-IR) spectroscopy and thermo-gravimetric analysis (TGA). The obtained PPESK- g-P(PEGMA) graft copolymer was used as an additive in the preparation of PPESK ultrafiltration membranes by phase inversion technique. X-ray photoelectron spectroscopy (XPS) analysis indicated that hydrophilic P(PEGMA) chains were excluded to membrane surface during membrane formation. Water contact angle measurements and protein filtration experiments showed that the surface hydrophilicity and the anti-fouling ability of PPESK membranes were significantly improved due to the surface enrichment of P(PEGMA) chains. Consequently, a hydrophilic surface modification for PPESK membrane was achieved by a simple single-step blending method.

ULTRAFILTRATION MEMBRANE FORMATION OF PES-C, PES AND PPESK POLYMERS WITH DIFFERENT SOLVENTS

Ultrafiltration membranes were prepared using phenolphthalein polyarylethersulfone (PES-C), polyethersulfone (PES) and poly(phthalazinone ether sulfone ketone) (PPESK) as polymers and NMP, DMAc, DMF and DMSO as solvents by immersion precipitation via phase inversion. Experimental data of thermodynamic properties of the polymer solutions and kinetic process of membrane formation were reported. For polymer solutions with good solvents, the sequence of the viscous flow activation energy (Eη) was coincident with that of the viscosity (η), without depending on the dissolving power of the solvents (characterized by intrinsic viscosity ([η])). The cloud point of the dilute polymer solutions was related to [η] of the polymer and gave a strong influence on the gelation rate in membrane formation process. The pure water flux (J) and the bovine serum albumin (BSA) rejection (R) of PES-C, PES and PPESK membranes were measured, the pure water flux (J) of membranes significantly depended on the gelation rate. The open porosity (OP) and the maximum pore size of membrane surface were calculated, and the relationship between membrane performance and membrane pore structure was discussed.

HYDROPHILIC MODIFICATION OF PPESK POROUS MEMBRANES VIA AQUEOUS SURFACE-INITIATED ATOM TRANSFER RADICAL POLYMERIZATION

Hydrophilic surface modification of poly(phthalazinone ether sulfone ketone) (PPESK) porous membranes was achieved via surface-initiated atom transfer radical polymerization (ATRP) in aqueous medium. Prior to ATRP, chloromethyl groups were introduced onto PPESK main chains by chloromethylation. Chloromethylated PPESK (CMPPESK) was fabricated into porous membrane through phase inversion technique. Hydrophilic poly(poly(ethylene glycol) methyl ether methacrylate) (P(PEGMA)) brushes were grafted from CMPPESK membrane under the initiation of benzyl chloride groups on membrane surface. The results of Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) confirmed the grafting of P(PEGMA) chains. Water contact angle measurements and protein adsorption experiments suggested that the hydrophilicity and anti-fouling ability of PPESK membrane were remarkably improved after the grafting of P(PEGMA) brushes. The addition of small amount of water in the reaction solvent apparently accelerated the progress of the grafting reaction. The use of CuCl2 in the catalyst system promoted the controllability of the ATRP reaction.

Tethering hydrophilic polymer brushes onto PPESK membranes via surface-initiated atom transfer radical polymerization

Surface-initiated atom transfer radical polymerization (ATRP) was used to graft hydrophilic comb-like poly((poly(ethylene glycol) methyl ether methacrylate), or P(PEGMA), brushes from chloromethylated poly(phthalazinone ether sulfone ketone) (CMPPESK) membrane surfaces. Prior to ATRP, chloromethylation of PPESK was beforehand performed and the obtained CMPPESK was prepared into porous membranes by phase inversion process. It was demonstrated that the benzyl chloride groups on the CMPPESK membrane surface afforded effective macroinitiators to graft the well-defined polymer brushes. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) confirmed the grafting of P(PEGMA) chains. Water contact angle measurements indicated that the introduction of P(PEGMA) graft chains promoted remarkably the surface hydrophilicity of PPESK membranes. The effects of P(PEGMA) immobilization on membrane morphology, permeability and fouling resistance were investigated. It was found that the comb-like P(PEGMA) grafts brought smaller pore diameters and higher solute rejections to PPESK membranes. The results of dynamic anti-fouling experiments showed the anti-fouling ability of the membranes was significantly improved after the grafting of P(PEGMA) brushes.

Effects of operation conditions, solvent and gelation bath on morphology and performance of PPESK asymmetric ultrafiltration membrane

AbstractThe effect of gelation temperature, evaporation time, solvent and gelation bath on the structure and performance of poly(phthalazinone ether sulfone ketone) (PPESK) asymmetric ultrafiltration membrane via phase inversion are investigated; the relationship between gelation thickness of dope solutions (X) and time for several polymer solutions with different solvents and gelation bath by online optical microscope–CCD camera experimental system (OM–CC system) are obtained. The results show that gelation temperature has much stronger influence on aperture opening ratio of membrane surface (AOR) and average diameter of membrane surface (AD) than evaporation time, whereas evaporation time has greater effect on the structure factor of membrane cross‐section (S). Bovine serum albumin rejection (R) is mainly determined by surface structure; however, pure water flux (J) is controlled not only by the structure of surface and cross‐section, but also the connectivity of the pores. PPESK membranes with fine performance can be fabricated under appropriate gelation temperature and evaporation time. In addition, the membrane structure and performance vary widely when various solvents and gelation bath are employed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Preparation and characterization of improved fouling-resistant PPESK ultrafiltration membranes with amphiphilic PPESK- graft-PEG copolymers as additives

Asymmetrical ultrafiltration membranes were prepared from poly(phthalazinone ether sulfone ketone) (PPESK) blends with the synthesized amphiphilic graft copolymers having a PPESK backbone and poly(ethylene glycol) (PEG) side chains (PPESK- g-PEG). The membranes were prepared by the traditional immersion precipitation method in a wet process. X-ray photoelectron spectroscopy (XPS) analysis and water contact angle measurements indicated that the hydrophilic graft copolymers preferentially segregated to membrane surface during membrane formation, contributing the membranes with enhanced surface hydrophilicity. The effects of coagulation bath composition and casting temperature on the surface enrichment properties of the graft copolymers, membrane morphology, permeability and fouling resistance were investigated. It was found that the elevation of casting temperature promoted the surface immigration of the additives, and consequently endowed PPESK membrane with higher surface hydrophilicity and permeability. Based on static protein adsorption and protein filtration experiments, the anti-fouling properties of the membranes were evaluated, and the results showed that the PPESK membranes incorporating with PPESK- g-PEG had a significantly improved resistance to protein fouling.

Synthesis of amphiphilic poly(phthalazinone ether sulfone ketone)-graft-poly(ethylene glycol) graft copolymers via Williamson etherification

Amphiphilic graft copolymers consisting of poly(phthalazinone ether sulfone ketone) (PPESK) backbones and poly(ethylene glycol) (PEG) side chains were synthesized via reaction of chloromethylated PPESK (CMPPESK) with a sodium alkoxide of methoxyl PEG (PEG- ONa). The reactive precursor, CMPPESK, was prepared by the chloromethylation of PPESK with chloromethylether (CME) using concentrated H2SO4 as reaction medium. FTIR spectroscopy, 1H-NMR and Solid-state 13C CP-MAS NMR analysis confirmed the covalent linking of PEG with PPESK backbones. The PEG content in the graft copolymers from 1H-NMR analysis varied from 21.0 to 37.2 wt %, which was approximately in agreement with that calculated from TGA tests. The graft products have good solubility in many aprotic polar solvents and can be slightly swelled by water and ethanol, but water insoluble. Contact angle measurements revealed that the hydrophilicity of PPESK was significantly improved by the introduction of PEG graft chains, indicating the graft copolymer is a potential hydrophilic additive for PPESK membranes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007.

Morphologies and properties of poly(phthalazinone ether sulfone ketone) matrix ultrafiltration membranes with entrapped TiO2 nanoparticles

AbstractPoly(phthalazine ether sulfone ketone) (PPESK) is a newly developed membrane material with superior thermal stability and comprehensive properties. Titanium dioxide (TiO2)‐entrapped PPESK ultrafiltration (UF) membranes were formed by dispersing uniformly nanosized TiO2 particles in the casting solutions. Initially, the inorganic nanoparticles were organically modified with silane couple reagent to overcome the aggregation and to improve the dispersibility in organic solvent. The membranes were prepared through the traditional phase inversion method. The effects of inorganic TiO2 nanoparticles on the membrane surface morphology and cross section structure were investigated using scanning electronic microscopy (SEM) and atomic force microscopy (AFM). Water contact angle (CA) measurement was conducted to investigate the hydrophilicity and surface wettability of the membranes. The influence of TiO2 on the permeability, antifouling, and tensile mechanical properties of the PPESK membranes were evaluated by UF experiments and tensile tests. The experimental results showed that the obtained TiO2‐entrapped PPESK UF membranes exhibit remarkable improvement in the antifouling and mechanical properties because of the introduction of TiO2 nanoparticles. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3623–3629, 2007

Preparation of UF and NF poly (phthalazine ether sulfone ketone) membranes for high temperature application

The ultrafiltration (UF) and nanofiltration (NF) membranes have been prepared successfully from poly (phthalazine ether sulfone ketone) (PPESK), a proprietary chemical of excellent thermal, chemical and mechanical stability. The effects of PPESK concentration, the type and concentration of additives in the casting solution on membrane permeation flux and rejection were evaluated by using orthogonal array of the design of experiments in separation of polyethyleneglycol (PEG). It is shown that PPESK concentration and the additive in the casting solution is the dominant factor on the rejection and permeation flux, respectively. The membrane performance is consistent and agrees with the theoretical analysis. The membranes were applied in the dye separation with the effects of evaporation time, heat treatment and the type of dye studied. The separation of a variety of dyes of 600–900 Da can be accomplished by the PPESK membranes properly prepared. Over 98% dye rejections were obtained for seven typical dyes. The permeation flux increases greatly by raising operation temperature and pressure without significant change of rejection.