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Meldrum's acid mediated ketene chemistry in the formation of dynamic ester bonds is employed in the synthesis of vitrimers with a high glass transition temperature above 210 °C.

Lignin recovery and valorization is desirable to optimize the process economics of the biorefinery with lignocellulose biomass as a feedstock. The recovery of high purity lignin from the brown solid (BS) residual obtained from a mid-stream waste of the rice straw biorefinery using the soda extraction process by adding ethylene glycol (EG) as a co-solvent is investigated in this study. The best extraction result was obtained with a lignin recovery of 94% and lignin content (purity) of 92% when the reaction time was 300 min at 190 ℃. The addition of EG increased the lignin solubility in the solution so that higher lignin yield and recovery could be obtained than that from the neat Soda process. The kinetic analysis indicated that the delignification reaction was composed of a fast bulk phase and a slow residue phase with a transition time at 60 min, corresponding to different levels of fragmentation, depolymerization and solubilization of lignin. In the fast phase, about 80% lignin can be solubilized in the solution quickly due to the predominant nucleophile attacks on the ether linkages (C-O-C, α-O-4, β-O-4, etc.). In the slow phase, the carbon-carbon (C-C) bonds are broken in the remaining residue lignin.

Solid polymer electrolytes (SPEs) are suitable materials for safety enhancements of high-energy-density lithium metal batteries. Low ionic conductivity and poor interfacial compatibility could be the major issues to be addressed for SPEs. In this work, a cross-linked polybenzoxazine polymer with poly(ethylene oxide) (PEO) segments (CR-PEO-PBz) has been synthesized and used as a polymeric matrix for preparation of SPEs. The cross-linked structure contributes to suppression of PEO crystallization. PEO-PBz is also used as a binder to reduce the interfacial resistance between the electrode and the electrolyte. The features enhance the lithium ion transportation and increase the ionic conductivity of the corresponding SPE (5.32 × 10–¹ mS cm–¹ at 60 °C). CR-PEG-PBz also exhibits the ability to prevent lithium dendrite growth with promotion of uniform lithium deposition. The LiFePO₄/Li coin cells made with the SPEs demonstrate a high initial capacity of 142 mAh g–¹ at 0.2C and 60 °C and a 93% initial capacity after a 100-cycle test. The cells could be operated at 30, 40, and 50 °C, thus proving the capability of the SPE at various temperatures.

Dynamic covalent bonds, particularly the ones exhibiting bond-breaking and bond-regeneration under ambient conditions, are attractive for the design and application of smart materials. This study demonstrates that the Meldrum's acid-based ketene chemistry is an effective approach to build up dynamic N-hindered amide bonds effectively workable at ambient conditions and under sunlight. The corresponding polyamides have been applied for sunlight-driven and self-repairing polymeric materials, and anticorrosion coatings. In addition to exhibiting sunlight-driven and self-repairing features on scratched surfaces, a high anticorrosion recovery of about 97% has been recorded. A smart anticorrosion coating requiring less maintenance is demonstrated.

Development of facile polymerization routes and new monomers is attractive for the development of polymer chemistry and materials. This study integrates the dual concepts in one work. Design and synthesis of Meldrum's acid (MA)-amine compounds as monomers and their corresponding self-polymerization based on ketene-mediated chemistry have been reported. An effective synthetic route to polyamides under a melt process in 20 minutes is demonstrated. Self-polymerization of the MA-amine compounds results in both linear and hyperbranched polyamides with high molecular weights, good film formability, and high mechanical strength. Flexible polyamide films prepared through a solution casting method show a high tensile strength of 122 MPa and an elongation at break of 6.7%. The designed monomers and synthetic route open a new window to both polymer chemistry and high-performance polymer materials.

This work reports a study on employing lignin in the formation of a selective layer of thin-film composite (TFC) membranes for pervaporation desalination. The TFC membranes with lignin-based separation layers are fabricated using a solution-casting method. With a reduction of the separation layer thickness to about 0.47 μm, a water permeation flux of 18.5 kg h−1 m−2 and a salt rejection of above 99.95% have been recorded on the lignin based TFC membrane with a feeding solution of 3.5 wt% NaCl(aq) at 45 °C. The membrane also exhibits high stability in long-term operation tests and can be applied for operations on high salinity water (up to 15 wt% NaCl(aq)). While being applied to seawater desalination, the membrane exhibits a water permeation flux of about 20.4 kg h−1 m−2 and a salt rejection of above 99.95% at 45 °C. A membrane separation process, which uses sustainable materials for salty wastewater treatments and water resource generation, has been demonstrated.

This work reports the first demonstration of the chemical reactions on the C–F groups of perfluorosulfonic acid polymers. The Nafion chains show chemical reactivity for atom transfer radical addition onto multiwalled carbon nanotubes and ability to serve as a macroinitiator for atom transfer radical polymerization. The C–F groups and mainchain −CF2 groups have been demonstrated, under a study with 19F NMR, as the active sites responsible for the reactions. The results could certainly extend both the scopes of chemistry and application of perfluorosulfonic acid polymers as well as the windows of atom transfer radical addition/polymerization to fluorinated compounds.

Furan-functionalized Meldrum's acid (MAF) has been utilized as a monomer for the preparation of self-crosslinkable polymers which possess Meldrum's acid (MA) moieties as the reactive sites. As MAF contains acidic C–H and furan groups, both are reactive toward maleimide groups, and polymerization has been carried out between MAF and multi-functional maleimide compounds. Both linear and hyperbranched MA-containing self-crosslinkable polymers have been prepared. The prepared polymers show good solubility in aprotic high polar solvents and high film formability. Self-standing and highly flexible crosslinked films have been obtained. The polymer film shows high solvent resistance, a high glass transition temperature of 298 °C, a high thermal stability above 340 °C, and attractive mechanical properties with a Young's modulus of 3.58 GPa and a stress at break of 34.4 MPa. Moreover, the crosslinked polymer films have relatively low-dielectric constants of about 2.85–2.78. An effective approach has been demonstrated for the preparation of high molecular weight MA-containing polymers and the corresponding thermosetting resin based self-standing and flexible polymer films.

Electrospun nanofibers of polybenzoxazines (PBzs) were fabricated using an electrospinning process and crosslinked by a sequential thermal treatment. Functionalization by the direct sulfonation process followed after the post-electrospinning modification treatment. The first stage of experiment determined the effects of varying the concentration of sulfuric acid as the sulfonating agent in the sulfonation reaction under ordinary conditions. The second stage examined the mechanism and kinetics of the sulfonation reaction using only concentrated H2SO4 at different reaction time periods of 3 h, 6 h, and 24 h. The mechanism of the sulfonation reaction with PBz nanofibers was proposed with only one sulfonic acid (–SO3H) group attached to each of the repeating units since only first type substitution in the aromatic structure occurs under this condition. The kinetics of the reaction exhibited a logarithmic correlation where the rate of change in the ion exchange capacity (IEC) with the reaction time increased rapidly and then reached a plateau at the reaction time between 18 h and 24 h. Effective sulfonation was confirmed by electron spectroscopy with a characteristic peak associated with the C–S bond owing to the sulfonate group introduced onto the surface of the nanofibers. ATR-FTIR spectroscopy also confirmed these results for varying reaction times. The SEM images showed that sulfonation has no drastic effects on the morphology and microstructure of the nanofibers but a rougher surface was evident due to the wetted fibers with sulfonate groups attached to the surface. EDX spectra exhibited sulfur peaks where the concentration of sulfonate groups present in the nanofibers is directly proportional to the reaction time. From surface wettability studies, it was found that the nanofibers retained the hydrophobicity after sulfonation but the inherent surface property of PBz nanofibers was observed by changing the pH level of water to basic, which switches its surface properties to hydrophilic. The thermal stability of the sulfonated nanofibers showed almost the same behavior compared to non-sulfonated nanofibers except for the 24 h sulfonation case, which has slightly lower onset temperature of degradation.

This work demonstrates a general and effective approach to activate inert polymer chains for further reactions through electrochemically driven radical generation and radical transfer reactions. The generated radical-containing polymer chains show capacity for further polymer reactions and preparation of polymer hybrids.

Porous polymer membranes have been widely used as matrixes of gel polymer electrolytes (GPEs) for lithium-ion batteries (LIBs). This work demonstrates the creation of lithium-ion-conducting channel...

Objective To investigate the relationship of TSH levels and TPOAb status before 20 weeks gestation with adverse pregnancy outcomes. Methods A total of 2885 pregnant women who underwent regular prenatal examination in Zhujiang Hospital of Southern Medical University during April 1, 2017 to October 31, 2018 were retrospectively analyzed. According to the TSH level before 20 weeks of gestation, they were classified into normal TSH (0.1 mU/L≤TSH0.05). In multi-factor logistic regression analysis results show that the risk of a preterm birth in group D, group E, group F were higher than that in control group, the risk of gestational diabetes in group F was higher than that in control group (OR>1, P

Employing crosslinkable polybenzoxazine (PBz) as the precursor, thermosetting resin based porous membranes possessing interconnected pores are prepared and applied for organic solvent phase microfiltration. The effects of the used solvents and additives on formation of interconnected pores in the obtained membranes are studied. Employing a solvent or an additive, which could build up hydrogen bonding based networks in the PBz solution, favors the formation of interconnected pores in the resulting membranes, as the polymer-solvent and polymer-additive networks could retard the mass transfers to result in a delayed demixing mechanism in the phase separation processes. 2-Pyrrolidone and lignin is an effective solvent and additive for formation of crosslinked PBz with interconnected pores. The crosslinked PBz/lignin membrane shows a high resistance to solvents, a high surface hydrophobicity with a water contact angle of about 141°, a high porosity of 70%, and a small pore size of 0.55 ± 0.05 μm. While being applied to a gravity-driven separation on a surfactant-stabilized water-in-toluene emulsion, the membrane demonstrates a flux of 278 ± 21 Lm−2h−1 and a water content of 474 ± 3 ppm of the permeated toluene, which is close to the natural solubility of water in toluene (411 ppm). This work has explored a new class of thermosetting resin based membrane with interconnected pores suitable for organic solvent microfiltration.

This work demonstrates a cross-linkable zwitterionic polymer, the corresponding zwitterionic thermosetting resin, and their application for antifouling surface coating. The tertiary amine-containing benzoxazine group is utilized as a precursor to react with 1,3-propane sultone to introduce sulfobetaine moiety to benzoxazine group. The reaction route provides an effective approach for preparation of sulfobetaine-functionalized benzoxazines and the corresponding sulfobetaine-functionalized thermosetting resins of benzoxazines. The sulfobetaine-functionalized polybenzoxazine has been utilized as a coating material for ceramic porous membranes to impart protein-repelling characteristic to the membrane surface. In a filtration test on a Bovine serum albumin (BSA) aqueous solution, the sulfobetaine resin modified membrane shows a 96.2% of rejection rate and a 1680 ± 9 Lm

OBJECTIVES Whether early medication reconciliation and integration can reduce polypharmacy and potentially inappropriate medication (PIM) in the emergency department (ED) remains unclear. Polypharmacy and PIM have been recognized as significant causes of adverse drug events in older adults. Therefore, this pilot study was conducted to delineate this issue. DESIGN An interventional study. SETTING A medical center in Taiwan. PARTICIPANTS Older ED patients (aged ≥65 years) awaiting hospitalization between December 1, 2017, and October 31, 2018 were recruited in this study. A multidisciplinary team and a computer-based and pharmacist-assisted medication reconciliation and integration system were implemented. MEASUREMENTS The reduced proportions of major polypharmacy (≥10 medications) and PIM at hospital discharge were compared with those on admission to the ED between pre- and post-intervention periods. RESULTS A total of 911 patients (pre-intervention = 243 vs post-intervention = 668) were recruited. The proportions of major polypharmacy and PIM were lower in the post-intervention than in the pre-intervention period (-79.4% vs -65.3%; P

In the present study, poly(ethylene glycol) (PEG) functionalized carbon nanotubes (CNT-PEG) were used as nanoadditives to fabricate hybrid membranes for enhanced CO2 separation in Pebax 1657 matrix...

This work reports the utilization of lignin, a renewable and biomass-based material, as an effective modifying agent for thermally stable and hydrophobic membranes based on crosslinked polybenzoxazine (CRPBz) to significantly enhance their permeation fluxes in pervaporation dehydration tests. Lignin could involve in the crosslinking reaction of polybenzoxazine so as to be chemically embedded in the polymer networks. In addition to the inherent hydrophilicity of lignin, lignin could release the hydrophilic groups (phenol and tertiary amine) of crosslinked polybenzoxazine with formation of hydrogen bonding with crosslinked polybenzoxazine, consequently to significantly enhance the hydrophilicity and water permeation fluxes of the studied membranes. With feeding a 70 wt% tetrahydrofuran aqueous solution at 25 °C, lignin modification increases the permeation flux of the CRPBz based membrane from 237 g m−2 h−1 to 490 g m−2 h−1 and separation factor from 11,920 to 19,440. Lignin modification significantly enhances the water permeation flux of the membrane without scarifying separation ability. A 3.4-folds of pervaporation separation index (PSI, the product of permeation flux and separation factor) has been demonstrated with the lignin modification. Similar performance has also been recorded on the tests on a 70 wt% isopropanol aqueous solution. The effect of lignin has been attributed to increase the membrane hydrophilicity for facilitating water permeation. The results demonstrate the wide application scopes of the lignin-modified CRPBz based membranes in pervaporation dehydration based on their high stability and hydrophilicity.

Inverse vulcanization involves reactions between elemental sulfur and unsaturated organic compounds to result in polysulfide materials. In this work, a Meldrum’s acid-containing styrene compound (M...

Meldrum's acid (MA) could be considered as a precursor of a highly reactive ketene group, and consequently is a suitable group for building up crosslinkable small molecular compounds and polymer chains. In this work, the Michael addition reaction of MA is applied for the preparation of multifunctional MA-containing compounds, exploring an effective route to synthesize multifunctional MA compounds, used as monomers for the corresponding MA-based thermosetting resins. Moreover, MA is utilized as a difunctional monomer to be polymerized with a bismaleimide (BMI) through the Michael addition reaction. A polymerization method directly using MA as a monomer for the synthesis of reactive and crosslinkable MA-containing polymers (poly(BMI-MA)) is demonstrated. The corresponding crosslinked CR-poly(BMI-MA) sample shows a high glass transition temperature (315 °C), high mechanical strength and a low dielectric constant of 3.15 at 1 MHz. A new type of MA reactive route and the corresponding high performance crosslinked resins are demonstrated.

Simple modification by thermal treatment is the commonly used approach to enhance the performance of electrospun fibers. This was investigated in the thermal treatment of polybenzoxazine (PBz) fibers blended with sulfur copolymers (SDIB) to determine the effect of varying treatment conditions on the microstructure and morphology of PBz fibers with the effect of incorporating sulfur functional groups on resulting properties. Mechanical properties of PBz are greatly improved by thermally-induced ring-opening polymerization (ROP) of the oxazine ring. Blending with sulfur copolymers (SDIB) could have beneficial effects on endowed features on fibers but could also affect the resulting properties of SDIB-blended PBz fibers during crosslinking reactions. Fiber mats were fabricated by electrospinning of PBz (10 wt%) blended with SDIB (10 wt%). Physical modification with varying conditions of sequential thermal treatment were evaluated and compared to the conditions applied on pristine PBz fibers. Changes in morphology and microstructure of fibers after modification were analyzed through scanning electron microscopy (SEM) while elemental compositions were identified after varying the conditions of thermal treatment. Adjustment of treatment conditions using two-step temperature sequential thermal treatment with higher temperatures of 160 °C and 240 °C showed significant changes in microstructure and morphology of fibers. Lower temperatures of 120 °C and 160 °C exhibited microstructure and morphology of fibers which affected the fiber diameter and fiber networks. Cross-sectional SEM images also confirmed the adversed effect of high-temperature treatment conditions on fibrous structures while low-temperature treatment retained the fibrous structures with more compact and stiff fiber networks. SDIB-blended PBz fibers were also evaluated by TGA and DSC to correlate the changes in structure and morphology with the thermal stability and integrity of blended SDIB/PBz fibers as compared to pristine PBz with the effect of change in treatment conditions. Fiber strength indicated slower weight loss for blended fibers and higher onset temperature of degradation which resulted in more thermally stable fibers.

Crosslinked membranes exhibiting in situ crosslinking and micro-cavity generation in membrane fabrication processes have been reported for pervaporation dehydration on methanol aqueous solutions. Meldrum's acid (MA) modified poly(2,6-dimethyl-1,4-phenylene oxide) (PPO-MA) with various MA contents have been synthesized and well characterized with Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy. PPO-MA polymers could perform thermally-induced self-crosslinking reaction through cycloaddition reaction between ketene groups generated from MA thermolysis reaction. Meanwhile, MA thermolysis reaction evolves CO2 and acetone molecules which contribute to generation of micro-cavities in the formed membranes. Consequently, compared to the pervaporative separation performance of pristine PPO membrane (permeation flux: 290 g m−2 h−1; separation factor: 57) on a 90 wt% methanol solution at 25 °C, the crosslinked PPO-MA membrane shows a separation factor of 809 with a slight decrease in permeation flux to about 226 g m−2 h−1. Based on the pervaporation separation index (PSI, the product of permeation flux and separation factor), an 11-times enhancement has been achieved.

This study aims to elucidate the effect of magnetic graphene oxide (GO) alignment in a polymer matrix on the ionic conduction and methanol barrier properties of the resulting composites. Magnetic iron oxide (Fe3O4) nanoparticles were fabricated and anchored on GO nanosheets. The magnetic GO-Fe3O4 nanofillers were incorporated into a quaternized polyvinyl alcohol (QPVA) matrix to form a polymeric composite. By applying a magnetic field (MF) along the in-plane direction during the drying and film formation steps, the GO-Fe3O4 nanosheets were aligned in an orientation parallel to the direction of the MF and connected to each other in elongated domains, as confirmed using transmission electron microscopy, field emission scanning electron microscopy/energy dispersive X-ray spectroscopy mapping, and laser scanning microscopy. The MF-aligned QPVA/GO-Fe3O4 electrolyte possessed higher conductivity and lower permeability than the un-aligned QPVA/GO-Fe3O4 membrane and pristine QPVA film. The aligned QPVA/GO-Fe3O4 composite exhibited a peak power density of 172.4 mW cm−2 at 60 °C, which is higher than those of the composite without the MF treatment (67.7 mW cm−2) and the pristine QPVA (50.3 mW cm−2). This research demonstrates the extraordinary benefits of MF assisted GO-Fe3O4 nanofillers in facilitating the ion conduction and barrier property of a polymeric composite at 0.1% filler loading.

In this work, crosslinkable polybenzoxazine (PBz), which exhibits high surface-covering ability, strong adhesion to metal substrates, and a dense crosslinked structure resistant to corrosion molecule permeation, has been demonstrated as an effective agent for single-component anticorrosion application. Plain crosslinked PBz-based anticorrosion coating shows a protection efficiency of 96.3%. Hierarchical surface structures and hydrophobicity have been introduced to the anticorrosion coatings through a biomimicking process using lotus leaves as templates, and so as to increase the protection efficiency to an extremely high level of 99.93%. Crosslinked PBz coatings with a hierarchical surface structure and surface hydrophobicity are highly effective for anticorrosion application. Moreover, biomimicking anticorrosion coatings have also been prepared with xanthosoma sagittifolium leaves to probe the template effect on the anticorrosion efficiency of the biomimicking coatings. Lotus leaves, rather than xanthosoma sagittifolium leaves, are the better choice for fabrication of the biomimicked anticorrosion coatings.

On the basis of the reaction between ketene and alcohol groups to result in an ester linkage and Meldrum's acid as an effective precursor of ketene group, a bifunctional aliphatic Meldrum's acid compound (BisMA) is synthesized and used as a monomer to react with ethylene glycol and glycerol for the preparation of linear and cross-linked aliphatic polyesters, respectively. A 62 and 35 wt % of biodegradation fraction have been recorded on the linear and cross-linked aliphatic polyesters after an 8 week biodegradation test, respectively, to demonstrate the good biodegradability of the synthesized polyesters. In addition to conventional linear biodegradable polyesters, this synthetic route also provides a new and convenient method for preparation of cross-linked biodegradable polyesters. The types of the required monomers and reaction methods for preparation of the cross-linked biodegradable polyesters are similar to those used for conventional thermosetting resins. An integration of biodegradable polymers and thermosetting resins in polymer chemistry has been demonstrated.

Polymeric membranes, compared with their inorganic counterparts, usually suffer from insufficient solvent resistance and thermal stability. In this study, an organic solvent–resistant thermally stable polymeric microfiltration membrane is prepared with a self-crosslinkable polybenzoxazine as a precursor. The obtained membranes have pore sizes of approximately 3.4 µm and superior antiswelling stability in organic solvents; thus, they exhibit excellent performance in terms of size-selective particle separation inorganic phases. The membranes are also effective in the gravity-driven separation of surfactant-stabilized water-in-oil emulsions. The water contents of the filtrate oil phases are close to the natural solubility of water in the solvents; for example, a water content of 350 ppm, which is comparable to the water solubility in toluene (330 ppm), has been found in the filtrate toluene from water-in-toluene emulsions. Moreover, the membrane demonstrates pH-induced changes in oil and water selectivity in oil–water separations. When treated with a strong base solution, the oil-selective membrane becomes water-selective and exhibits favorable performance in terms of separating organic solvents from surfactant-stabilized oil-in-water emulsions. These features effectively extend the application scope of the prepared membrane for oil–water separations.

Meldrum's acid (MA) groups are incorporated into polydimethylsiloxane (PDMS) chains as reactive units to impart self-crosslinkable and modifiable features to PDMS. The synthesis of MA-functionalized PDMS (MA-PDMS) has been performed through hydrosilylation reactions using an MA-functionalized bifunctional styrenic compound and Si–H terminated dimethylsiloxane compounds as monomers. The MA-PDMS samples exhibit number-averaged molecular weights of about 5000–10 000 Da and have been spectrally characterized with Fourier transform infrared and 1H and 29Si nuclear magnetic spectroscopies. Thermolysis of the MA groups of MA-PDMS is traced with thermal analysis (differential scanning calorimetry and thermogravimetric analysis) to demonstrate the reactivity of MA-PDMS. Self-crosslinking and post-modification reactions of MA-PDMS are carried out with the ketene groups generated from the MA thermolysis reaction through ketene dimerization and nucleophilic addition reactions, respectively. A phosphorus compound (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, DOPO) is utilized as the modifier for MA-PDMS post modification so as to result in DOPO-functionalized PDMS (DOPO-PDMS). Based on the developed reaction routes, this work also demonstrates a convenient and effective approach for preparing DOPO-functionalized-PDMS compounds, which are potential flame retardants for polymeric materials exhibiting Si/P synergistic effects on flame retardation.

Nitroxide-functionalized polymers are attractive macroinitiators for nitroxide mediated polymerization (NMP) and further modification of polymers. In this work, a facile reaction method to chemically bond nitroxide groups to polymer chains has been demonstrated with incorporation of 2,2,6,6-tetramethylpiperydinyl-1-oxyl (TEMPO) groups into poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) through the atom transfer radical coupling reaction. The TEMPO-functionalized PPO (PPO-TEMPO) has been used as a macroinitiator for NMP of styrene to result in the corresponding PPO-g-PS graft copolymers. Moreover, PPO-TEMPO could be used to carry out a thermally-induced self-crosslinking reaction through radical coupling. The crosslinked PPO displays enhanced mechanical properties, reduced oxygen permeability coefficient (from 22.5 barrer to 3.5 barrer), low dielectric constant (2.40 at 10 GHz) and low dissipation factor (0.008 at 10 GHz), so as to have high potential for application in dielectric layers of microelectronics.

Efficient separation of both immiscible and emulsified oil/water mixtures is achieved by collaborating polybenzoxazine (PBz) with commercially available substrates in this work. Possessing intrinsic low surface energy, crosslinked PBz coating endows various substrates (sponges, filter paper, and ceramic membrane) with surface hydrophobicity and oleophilicity and enables oil-selective penetration. The as-prepared sponge (CR-PBz-sponge) could effectively remove oil floating on water and oil under water with high absorption capacities (up to 120 times its own weight) and good recyclability. The PBz-coated filter paper (CR-PBz-filter paper) is applicable to efficient large-scale oil/water separation based on its high fluxes (about 5000–6000 L m −2 h −1 ) on a wide range of organic solvents and oils. CR-PBz-ceramic membrane shows great effectiveness in removal of tiny water droplets from water-in-oil emulsion and reduces the water contents of the treated oil to the levels of the natural water solubility of the oils. Based on its separation efficiency, processing simplicity, substrate versatility and low cost, the technique of using PBz as coating material to fabricate oil/water separation materials is promising in practical and industrial concerns.

The instability of the lithium and electrolyte interface as well as the lithium dendrite growth could be the major issues for the practical application of lithium metal batteries. This work provides an effective solution to the issues with employing a crosslinked polyimide for preparation of thermally-stable separators. The effect of porous morphology of the separators from various porous membrane-formation methods on their electrochemical properties and the corresponding cell performance has been examined and discussed. The separator made with the non-solvent-induced phase separation (NIPS) has an asymmetric structure possessing a macro-void matrix and a relatively dense layer containing nanoscale pores. This top layer plays as a barrier to prevent the lithium dendrite growth and penetration into the separator. The nanoscale pores in the top layer allows ion migration to ensure the high ionic conductivities. The cells employing the prepared separators are capable of operating at high C rate (10C) and show high stability in cycle tests. A straightforward approach for thermally-stable separators with self-protective layers and inhibition of lithium dendrite growth has been demonstrated.

Gel polymer electrolyte (GPE), possessing a polymer matrix and embedded liquid electrolyte, is a critical component of lithium-ion batteries. To enhance GPE performance, in this work a self-crosslinkable poly(vinylidene difluoride) (PVdF) graft copolymer possessing Meldrum's acid (MA) groups as reactive sites has been prepared with atom transfer radical polymerization and utilized as a polymer matrix for GPEs. Compared to neat PVdF based GPEs, incorporation of MA groups to PVdF chains simultaneously brings crosslinking characteristic and high polarity to PVdF chains so as to enhance the thermal stability, mechanical strength, and polymer matrix-electrolyte affinity of the corresponding GPEs. The prepared GPE has an ionic conductivity of about 1.48 mS cm−1, which is higher than the value of 0.98 mS cm−1 measured on commercial Celgard 2325® separator. Moreover, good Li-ion battery performance, including high discharge capacity (136 mAh g−1 at 0.2 C) and high capacity retention at high C-rates (66% at 10 C and 50% at 15 C), has been recorded with the prepared GPE based LIBs, demonstrating the application potential of the developed GPE for fast-charging lithium-ion batteries.