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Ultrafine SnO2/Sn nanoparticles encapsulated into the adjustable mesoporous carbon matrix has been successfully fabricated by a facile route. The mesoporous carbon effectively improve the conductivity of the SnO2/Sn, prevent the aggregation, accommodate the strain of volume change and provide high interface area with the electrolyte, thus resulting in excellent cycling performance. A reversible capacity of 1105 mAh g–1 still retained after 290 cycles at 200 mA g–1, and the capacity still can keep at 107 mAh g–1 at high current density of 10 A g–1. The porous structures by the in situ SiOx template provide an appropriate specific surface area, which contributes to a relatively high capacitive contribution.

Additive approach provides a simple, yet very effective way of improving the performance of polyamide (PA) thin film composite (TFC) membranes. However, the correlation between physical and chemical properties of a wide range of additives and the final membrane properties is still barely understood. In this work, a variety of additives were systematically used to prepare RO membranes to provide fundamental mechanistic understanding of membrane performance improvement by additives. The membranes were characterized in detail by FTIR, XPS, SEM, AFM, water contact angle, zeta potential, QCM etc. The separation performance of the TFC membrane was measured with 2000 ppm NaCl solution at 1.5 MPa and 25 °C. The results show that by adding DMSO, formamide, acetamide into the aqueous solution, or cyclohexanone into the organic phase, approximately 2 times higher water flux was achieved without significantly decreasing salt rejection. Both aqueous and organic phase additives bring out better MPD diffusion and higher crosslinking density. However, their effect on the kinetic of interfacial polymerization are different. The aqueous phase additives promotes the formation of a thinner and smoother PA selective layer with less film mass, while the organic phase additives sustain the solubility of PA oligomers so that the film mass increases and greater film mass correlates with improved membrane flux.

Binders play a crucial role in maintaining mechanical integrity of electrodes in lithium-ion batteries. However, the conventional binders lack proper elasticity, and they are not suitable for high-performance silicon anodes featuring huge volume change during cycling. Herein, a poly(siloxane imide) copolymer (PSI) has been designed, synthesized, and utilized as a binder for silicon-based anodes. A rigidness/softness coupling mechanism is demonstrated by the PSI binder, which can accommodate volume expansion of the silicon anode upon lithiation. The electrochemical performance in terms of cyclic stability and rate capability can be effectively improved with the PSI binder as demonstrated by a silicon nanoparticle anode.

Silicon anodes have attracted much attention owing to their high theoretical capacity. Nonetheless, an inevitable and enormous volumetric expansion of silicon in the lithiated state restrained the development of the silicon anode for lithium-ion batteries. Fortunately, the utilization of the high-performance binder is a promising and effective way to overcome such obstacles. Herein, a polymer of intrinsic microporosity (PIM) is applied as the binder for the silicon anode, which is composed of a rigid polymer backbone, an intrinsic porous structure, and active carboxyl groups (PIM-COOH). Compared to the traditional binder, both the long-term stability and rate performance of the electrode using PIM-COOH as the binder are significantly improved. The mechanism responsible for the enhanced performance is investigated. The PIM-COOH binder provides stronger adhesion toward the current collector than the conventional binders. The unique rigid polymer backbone and porous structure of the PIM-COOH binder enable a good capability to withstand the volume change and external stress generated by the Si anode. The porous structure of the PIM-COOH binder enhances lithium-ion transportation compared to the SA binder, which improves rate performance of the silicon anode. This work provides a unique insight into design, synthesis, and utilization of the binders for lithium-ion batteries.

Surface positve-charged composite membranes were prepared through two guanidine group containing polymers, polyhexamethylene guanidine (PHMG) and polyhexamethylene biguanidine (PHMB). They were used as aqueous phase monomers in an interfacial polymerization (IP) process reacting with trimesoyl chloride (TMC) on the surface of polysulfone (Psf) ultrafiltration membrane. Piperazine (PIP) provided the best pH adjustment among the chosen regulators. As guanidine groups dissociate in water and bring ammonium cations to membrane surfaces, both polyguanidine endowed membranes reacted with divalent metal cations better compared with Na+ and Li+. The rejection rates were more than 90% for all chosen divalent metal salts. PHMG membranes displayed excellent enrichment of Li+ from a mixed solution of Mg2+ and Li+ salts. The Mg2+/Li+ mass ratio decreased from 60 to 3.7, accompanying a −3.6% rejection to Li+. Although partial guanidine groups participated in the IP reaction, bactericidal rates of membranes were both higher than 99% in Gram-negative E. coli and Gram-positive S. aureus tests.

This study was conducted to comprehensively evaluate the role of hydraulic retention time (HRT) on simultaneous removal of nitrate and micropollutants (MPs) in secondary effluent from wastewater treatment plants in post-denitrification fixed biofilm reactor (PDFBR). Results showed that PDFBR was favorable for nitrate removal (above 94%). Prolonged HRT promoted the bio-utilization of nonaromatic soluble microbial products with low molecular weight and reduced biomass production. MPs was partially removed in PDFBRs (below 48%). Microbial diversity increased along the extending of HRT and thus partially enhanced MPs removal. Batch experiments showed that changing HRT had no direct impact on the biodegradation rates of the selected MPs. Correlation analysis revealed that Dechloromonas, Terrimonas, and Phreatobacter were reasonable for simultaneous removal of MPs and nitrate. The abundance of nosZ gene had a rapid decrease under extreme HRT. This study provides insights into polishing nitrate and MPs from secondary effluent in a denitrifying biofilm system.

Metal–organic framework (MOF) membranes exhibit enormous potential for molecular mixtures’ sieving with high permeance, as well as high selectivity. Current MOF composite membranes suffer from unduly thick MOF layer and poor adhesion to the porous support. By a simple multiple seeded growth method, the ultrathin (less than 200 nm) and defect-free MOF layer is prepared on a ZIF-8 in-situ embedded PSf substrate. On the one hand, the nano-sized ZIF-8 crystals embedded on substrate surface act as anchors linking the ZIF-8 layer with the substrate. On the other hand, these ZIF-8 crystals also act as seeds to promote the formation of the ZIF-8 layer and reduce the crystallization time, leading to a thin and continuous ZIF-8 layer. The obtained ultrathin ZIF-8 membrane shows superior gas molecular sieving performance, with a high gas permeance of 24.5 × 10−7 mol/m2/s/Pa for H2 and selectivity of 4.5, 23.2, and 31.5 for H2/CO2, H2/N2, and H2/CH4, respectively. In addition, neither the permeance or the selectivity shows a noticeable change after 3% elongation, which indicates high mechanical integrity of the MOF layer on the ZIF-8 in-situ embedded PSf substrate. We believe that the utilization of MOF in-situ embedded polymer substrate offers a universal and simple strategy strengthening and thinning the MOF layer of its composite membranes.

The traditional methods to introduce multi-functional groups onto the surface of membrane require unpleasant reaction conditions and complex procedures. Motivated by the need of an economical purification method in the downstream processing of therapic proteins, we develop a simple approach to fabricate mixed mode membrane adsorbers. Nanofibrous membrane support was fabricated by electrospinning a blend of poly(styrene-co-maleic anhydride) (SMA) with polyvinylidene fluoride (PVDF). Mixed mode ligands were then immobilized on the membrane through the conversion of anhydride moieties by aminolysis with functional amines, n-butylamine (BAE), n-octylamine(OAE), N-methyl- d -glumine(NMG). The obtained mixed-mode membrane adsorbers, PVDFS-g-BAE, PVDFS-g-OAE, and PVDFS-g-NMG, which contain hydrophobic interaction/ion exchange, reverse phase interaction/ion exchange, and hydrophilic interaction/ion exchange interactions respectively, were used for protein separation. The success of modification was supported by FTIR and XPS, indirectly confirmed by WCA measurements. Static protein binding property was measured with several model proteins. The PVDFS-g-BAE membrane showed a capacity of 120 mg/mL for IgG and fair selectivity over BSA or Lym; The PVDFS-g-OAE membrane showed a capacity of 140 mg/mL for ɑ-CTP and high selectivity over CYT-C. In addition, the nanofibrous membrane has large total pore area, high porosity, and good mechanical property, which is sufficient for the demands of practical use.

In order to improve the antibacterial efficiency and spectrum of cellulose acetate reverse osmosis membrane (CA–RO), both quaternary ammonium and bromoacetyl groups were introduced into cellulose diacetate under mild conditions forming CA–RO with bi-antibacterial groups for seawater desalination. Bromoacetyl bromide and a series of tertiary amine were chosen as the modification agents respectively. The characterization results showed that both two antibacterial groups were successfully introduced with a certain density. The obtaining membrane had a less hydrophilic but more electronegative surface as well as improved mechanical property. The flux values increased firstly and decreased subsequently after twice modifications while the salt rejection rose. The membrane modified with N,N-dimethyloctylamine (DMOA) had the optimal comprehensive performance of flux and salt rejection. The antibacterial testing results indicated that the resulting RO membranes showed high antibacterial efficiency and broad-spectrum. Their bactericidal rates against gram-negative Escherichia coli (E. coli) and gram-positive Staphylococcus aureus (S. aureus) were more than 99.9%.

By blending the modified laponite (OHec) and polyacrylonitrile (PAN), we prepared polyacrylonitrile nanofiber membranes (PAN@OHec) using the electrospinning technique. Then, the amidoxime modification was carried on using the hydroxylamine hydrochloride, yielding NH2 contained amidoximated polyacrylonitrile nanofiber membranes (AO-PAN@OHec). Amino acids were grafted onto AO-PAN@OHec by a hydrothermal method to prepare materials with a good hemocompatibility. The morphology, structure, wettability, and chargeability of the modified Lys-PAN@OHec nanofiber membranes were characterized by Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), Energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), WCA and Solid zeta potential measurements. We investigated the anti-protein contamination ability of the modified PAN nanofiber membranes. Hemocompatibility of the modified PAN nanofiber membranes were evaluated by the adhesion property of the platelet and erythrocyte. As a result, the hydrophilicity of the modified PAN nanofiber membranes were significantly improved. The protein adsorption was decreased. Besides, the modified membranes were proved to suppress the adhesion of platelet and erythrocyte compared with original PAN membranes.

Direct non-oxidative methane conversion (DNMC) has been recognized as a single-step technology that directly converts methane into olefins and higher hydrocarbons. High reaction temperature and low catalyst durability, resulting from the endothermic reaction and coke deposition, are two main challenges. We show that a millisecond catalytic wall reactor enables stable methane conversion, C2+ selectivity, coke yield, and long-term durability. These effects originate from initiation of the DNMC on a reactor wall and maintenance of the reaction by gas-phase chemistry within the reactor compartment. The results obtained under various temperatures and gas flow rates form a basis for optimizing the process towards lighter C2 or heavier aromatic products. A process simulation was done by Aspen Plus to understand the practical implications of this reactor in DNMC. High carbon and thermal efficiencies and low cost of the reactor materials are realized, indicating the technoeconomic viability of this DNMC technology.

It remains a major challenge to prepare membranes with minimal protein adsorption for bio-related applications. In this work, modified polyvinylidene difluoride (PVDF) membranes having ultralow protein adsorption were prepared by grafting zwitterionic and PEGylated cross-linked polymers onto the membrane surface. The PVDF membrane was first treated with alkaline and tethered with cross-linked polyethylene glycol diacrylate (CPEGDA) via ATRP. By reacting the abundant alkene group at the periphery of CPEGDA with cystine or monomethyl PEG thiol (MPEG-SH, Mn = 200, 600, 2000) by thio-ene reaction, the membrane surface was tethered with high density protein repellent groups. The PVDF-g-CLPEG2000 membrane shows the best performance and its bovine serum albumin (BSA) and bovine serum fibrinogen (BFG) adsorptions can be lowered to only 1/50 and 1/40 that of the original PVDF membrane, respectively. Similar fouling tendencies were observed in the dynamic filtration process. This work addresses the significance of cross-linked grafting on altering membrane surface properties.

MXene, a family of two-dimensional transition metal carbides/nitrides, is one of the most attractive photothermal materials due to its unique hydrophilicity, tunable surface activity, and outstanding photothermal conversion performance by absorbing near-infrared light or solar light. The integration of MXene into three-dimensional polymer hydrogels opens up new possibilities for developing advanced material platforms. In this review, we summarize the synthesis of MXene-based hydrogels and highlight their recent progress in photothermal applications. Challenges and perspectives for future research are also outlined.

The combination of mixed-mode chromatography (MMC) and molecular imprinting technology (MIT) has been proven to be successful for protein separation, but suffered from cumbersome material preparation and limited performance. In this work, a new modification method marrying atom transfer radical polymerization (ATRP) and multicomponent reaction was proposed to simplify the preparation process. Using regenerated cellulose (RC) membrane as the substrate, immunoglobulin G (IgG) as the template protein and tryptamine as the ligand, a dual-recognition membrane adsorbers (MIM) was prepared by mild Ugi four-component reaction (Ugi-4CR) and surface initiated ATRP. Control the ATRP time is the key for surface imprinting. The static IgG uptake and selectivity of UGI membrane were 45 mg/mL and 1.8, respectively, while those of MIM-0.5 were 42.5 mg/mL and 14, indicating that the introduction of molecular imprinting technology significantly improved the selectivity of the membrane to IgG. The MIM-0.5 membrane retains the pH-dependent and salt-tolerant of HCIC. The dynamic flow-through results showed that the MIM-0.5 membrane could effectively separate IgG from IgG/BSA mixed solution with the purity of 88% and retained its bioactivity. This work demonstrated the feasibility of bonding HCIC and MIT to the membrane surface by Ugi-4CR and ATRP.

Background Mixed matrix membranes (MMM)s for CO2/N2 separation still suffer from interfacial defects. Method To address this, a series of MMMs were prepared using polyethersulfone-g-poly (ethylene glycol) (PES-g-PEG) comb-like copolymer to tune the interfacial interaction with a pillared MFI (PMFI) zeolite nanosheets, which has a hierarchical porous structure to improve permeance. The composite membranes were examined by SEM, EDX and XRD. The dependence of gas permeabilities, diffusion and solubility coefficients of CO2 and N2 were determined by the time-lag method. Results The increase in PMFI zeolite loading led to an increase in the permeability coefficient of CO2, which is mainly caused by the increase in CO2 diffusion coefficient. The CO2/N2 gas separation was optimized at a loading of 20wt% PMFI zeolite, which produces a composite membrane with a CO2 permeability of 66.9 Barrer and an ideal permeability selectivity coefficient of 9.6.

Hydrophobic charge-induction chromatography (HCIC) is a novel technology for antibody purification. The interaction between immunoglobulin G (IgG) and HCIC ligands was investigated by dissipative quartz crystal microbalance (QCM-D). HCIC ligands 2-mercapto-1-methylimidazole (MMI), 2-mercaptobenzimidazole (MBI) and 2-mercapto-4-methylpyrimidine hydrochloride (MMp) were coupled to the surface of a self-assembled monolayer (SAM) terminated by epoxy groups. The ellipsometric ligand densities of MMI, MBI and MMp on the SAMs were 1.54, 1.64 and 1.47 chain/nm2, respectively. QCM results indicated the Au–MBI sensor to exhibit excellent performance in IgG adsorption compared with other sensors, with a maximum adsorption capacity of 1601 ng/nm2 and a dissociation constant of 2.84 × 10−6 M. The structure of the adsorbed IgG layer changed as a result of changes in the pH of the protein buffer and the addition of free and stable salts, probably due to changes in IgG conformation. According to Au–MBI surface regeneration experiments, the degree of regeneration afforded by NaOH 0.1 M was 99.7%. The QCM-D platform based on SAMs proved to be a powerful tool for studying ligand–protein interactions and the structures of protein adsorption layers. This study provides accurate theoretical guidance for the practical application of protein adsorption and antibody purification procedures.

Biofouling severely limits the application of reverse osmosis (RO) for water treatment. In this work, a green surface in-situ reduction method based on the tannic acid-inspired chemistry was used to introduce silver nanoparticles (AgNPs) into the intermediate layer of a thin film nanocomposite (TFN) membrane, as effectively improved the anti-biofouling performance of the membrane without sacrificing its desalination performance. SEM, EDX, AFM, XPS, DSA, ATR-FTIR and zeta potential were used to characterize the membranes. The plate counting method and confocal laser scanning microscopy (CLSM) were used to evaluate the anti-biofouling performance. And the long-term Ag+ release rate was measured using ICP-MS. Compared with unmodified thin film composite (TFC) membranes, the permeation flux of TFN membrane is improved while retaining the salt rejection. By optimizing the soaking time of FeCl3 and AgNO3 on the PSF membrane surface during the preparation of the intermediate layer and the M-phenylenediamine (MPD) and trimesoyl chloride (TMC) concentration for the interfacial polymerization. A water flux of 34.5 ± 1.2 L/m2 h and a salt retention of 98.0 ± 0.3% were achieved under the operating pressure of 1.55 MPa and 25 °C, for a 2000 ppm NaCl solution. The killing rates of the membrane to E. coli and S. aureus are almost 100% for a 24 h and 48 h contacting time. The number of bacteria attached to the membrane surface is far less than that of the unmodified membrane. More importantly, the Ag+ release rate was stable and controllable, allowing for long-term antibacterial properties.

The synergized optimization of water flux and salt rejection by blending with inorganic fillers has been achieved for the polyamide (PA) thin film nanocomposite (TFN) membrane. However, it is difficult to characterize its mass transport properties due to the very thin and heterogeneous PA film. In this work, we select cellulose triacetate (CTA) as the base to prepare hybrid films and their transport properties were studied according to solution-diffusion theory. A series of inorganic fillers, such as reduced graphene oxide (RGO), zeolites, ZIF-8, SiO2 and graphene oxide (GO) were incorporated. The SEM and EDX results indicate a less than 1 wt% filler content for a uniform dispersion. The blending of inorganic fillers leads to enhanced glass transition temperature (Tg) and density, little effect on the water transport property but dramatically decreased salt permeability values, which are nearly ten-fold of that of the CTA film. The blending of GO can densify and hydrophilize CTA simultaneously, which is most promising for a desalination application. The increased water uptake should contribute to its increased water permeability, while the decreased free volume size and FFV value and various interactions between the ions (Na+, Cl-) and GO sheets account for salt permeability decrease.

Hydrophobic charge-induction chromatography (HCIC) has emerged as an efficient method for antibody purification, but traditional packed-bed chromatography continues to suffer from high pressure drop and low transport efficiency. A versatile surface modification method is proposed to prepare HCIC membrane adsorbers. We first modified a commercial regenerated cellulose (RC) membrane by the cationic ring-opening polymerization (CROP) of diethylene glycol diglycidyl ether (DEGDE), producing the RC-g-PDEGDE membrane, which was then modified by the ring-opening reaction of an epoxy group with a sulfydryl group in four mercaptoheterocyclic ligands. Bovine serum albumin (BSA) and human immunoglobulin G (IgG) were used as model contaminant and antibody, respectively. The highest ligand density achieved is 370 mmol/L, and the static and dynamic adsorption capacities of IgG reached 195 and 65 mg/mL, respectively. The high dynamic capacity and IgG recovery (96%) are believed to benefit from the branched structure of ...

Acid-resistant membrane has an important application prospect in the field of industrial wastewater treatment. Polysulfonamide (PSA) filtration membrane possessing good stability in acidic condition was often hampered for application due to the poor performance by the state-of-the-art interfacial polymerization (IP) preparation method. Herein, a spinning-assist multilayer interfacial polymerization (sMIP) method was devised and employed for the fabrication of a PSA thin-film composite (TFC) membrane from piperazine (PIP) and 2,4,6-tris(chlorosulfonyl) phenol (TCSP). Membrane fabricated with 5 layers by sMIP method exhibited greater than 98% rejection rate for Na2SO4 and MgSO4 and outperformed the control IP group by ~ 147% enhanced water permeance and a magnitude greater permselectivity due to a reduced active layer thickness. Compared with polyamide membranes, the PSA TFC membrane exhibited better stability toward acid through a high-temperature treatment in a 20% H2SO4 aqueous solution. For a CuSO4 and H2SO4 mixed solution filtration, the PSA membrane exhibited good permselectivity with CuSO4 rejection of 78% and H2SO4 rejection of 8% at a permeate flux of 13.98 L m−2 h−1. These results have demonstrated that the sMIP method provides an effective way to fabricate polysulfonamide membrane with excellent salt rejection as well as appreciable water permeance.

The antibacterial alkyl bromide groups were introduced into cellulose diacetate (CDA) through the esterification between highly active bromoacetyl bromide and hydroxyl groups under mild conditions and the modified cellulose acetate reverse osmosis membrane (Br-CA-RO) was obtained subsequently after phase inversion process. The results of FTIR and 1H-NMR indicated the existence of alkyl bromide groups in the modified CDA powder. The optical density method was used to confirm its antibacterial ability. The chemical structure and morphology characterization demonstrated that the anchoring of bromoacetyl groups as antibacterial part brought out minimal alteration on membrane chemical structure and its asymmetric structure, but the regularity and density of membranes increased with the degree of esterification. The property testing results showed that the whole physical performance was enhanced with the thermal stability getting slightly worse. Both the flux and salt rejection of Br-CA-RO increased after modification and the latter was close to that of cellulose triacetate RO membrane. The dynamic contact antibacterial testing implied that Br-CA-RO showed much higher antibacterial ability than unmodified RO membranes, and its relative bactericidal rates against E. coli (gram negative) and S. aureus (gram positive) were higher than 73.0% and 93.5%, respectively. This method offers a new approach for antibacterial and functional modification of CA-RO membranes.

Ideal adsorbents are featured by both high adsorption capacity and high adsorption rate. Current adsorptive membranes enjoy good mass transfer performance but have limited sorption capacity. Microporous organic polymer has superiorities of small pore size and high surface area which is conductive to high adsorption capacity, but usually suffers from high mass transfer resistance. In this work, the polymer of intrinsic microporosity PIM-1 was fabricated into microfiber membranes by electrospinning for carbendazim and phenol adsorption. The PIM-1 and its electrospun membranes were characterized by 1H NMR, GPC, ATR-FTIR, FESEM, TG and BET measurements. The electrospun PIM-1 membrane was demonstrated to have hierarchical porous structure with high surface area. The equilibrium adsorption capacity for carbendazim and phenol was 0.084 mmol/g and 0.804 mmol/g, respectively. The adsorption isotherm fits well with Langmuir model and the adsorption kinetic can be described by film diffusion and chemical reaction model. The membrane can retain 95% of its initial capacity after cycling 10 times. Both the sorption capacity and kinetic coefficients are high when comparing with other sorbents for either carbendazim or phenol, demonstrating that the electrospun PIM-1 is a good adsorbent.

A novel procedure to fabricate quaternized cellulose triacetate reverse osmosis (QCTA-RO) membranes via the etherification procedure between partially hydrolyzed CTA-RO membrane and 3-chloro-2-hydroxypropyl-trimethyl ammonium chloride (CHPTAC) in alkaline solutions (pH = 9–11) for different reaction time (1, 2, 3 and 4 h) was proposed. The structure and performances of the obtained QCTA-RO membranes were characterized and their antibacterial performances against E. coli and S. aureus were evaluated through colony counting method. The results showed that quaternary amine group was successfully grafted on the surface of membrane via covalently bond without significant damage to morphology, mechanical performance and thermal stability. The permeation flux values increased with prolonging modification time to 3 h, while the salt rejection decreased slightly but remained above 92%. QCTA-RO membranes displayed good antibacterial activity against Gram-negative E. coli and Gram-positive S. aureus and their bactericidal rates were 78.7–89.0% and 64.7–76.6% respectively at the optimized modification time of 2–3 h.

The deployment of fossil resources such as petroleum, coal and natural gas to produce fuels and chemicals has resulted in excessive carbon dioxide (CO2) emissions and serious environmental issues. The implementation of CO2 utilization as a raw material for synthesis of fuels and chemicals has potential to reduce CO2 emissions and close the carbon cycle. Cyclic carbonates, materials used as building blocks for polymers or green solvents in batteries, can be synthesized from CO2 and alkylene oxides. Although a variety of catalysts have been synthesized to activate CO2 and alkylene oxides for transformation into cyclic carbonates, either the catalytic efficiency is low or the catalyst cost is high. In the present work, we report a hierarchical porous metallized poly-melamine-formaldehyde (PMF) polymer catalyst that has a 100-fold monomer cost reduction and six- to several hundred-fold activity enhancement compared to the state-of-the-art catalysts for propylene carbonate synthesis from epoxide and CO2 under the same reaction conditions. The hierarchically interconnected macro-, meso- and micro-pore structures in PMF that are formed via one-step high internal phase emulsion polymerization facilitate mass transport and accessibility to active sites. The high density of aminal groups and triazine rings in PMF provides multiple sites for CO2 adsorption and the subsequent reaction with epoxide. The unprecedented low-cost and high-efficiency of metallized PMF as well as the simplicity in its synthesis exhibit great potential in the synthesis of cyclic carbonates for the chemical and plastics industries.

A fast and facile protocol is reported aiming at improving the antifouling property and hemocompatibility of poly(vinylidene fluoride) (PVDF) membranes by tethering PEG hydrogel and zwitterion immobilization. The coated PEG hydrogel was first prepared by interfacial polymerization and tethered on an alkali treated PVDF membrane (PVDFA) surface via a simultaneous thio-ene and thiol-epoxy reaction. Then, the thiol groups of cysteine reacted with the epoxy groups in PEG hydrogel to fabricate the PVDFA-g-Cys membrane. The membrane fabrication was complete within less than 20 min and was conducted in mild conditions. The successful preparation of PVDFA-g-Cys membrane was confirmed by ATR-FTIR and XPS. Raman spectroscopy showed that the hydrogels covalently bonded to the PVDF membrane surface. The membrane retained its mechanical strength after modification. The SEM measurements suggested that the membrane became denser after hydrogel coating, meanwhile, the EDX test verified that the functional species uniformly distributed in the membrane matrix. Water contact angle (WCA), protein adsorption and protein filtration tests showed significant improvements in hydrophilicity and antifouling properties for the modified membrane. The negativity of the membrane surface measured by the streaming potential method provides a basis for protein resistance and hemocompatibility. Moreover, the suppressed platelet adhesion and prolonged plasma coagulant time show that the PVDFA-g-Cys membrane has ultralow thrombotic potential and better hemocompatibility. The reported surface modification method combing thio-ene and thio-epoxy chemistry not only facilitates fabrication of hemocompatible PVDF membrane but also provide an universal chemical platform for multifunctionalization of porous membranes.

Micropollutants (MPs) present in water have shown increasing threat on the ecosystem. Membrane adsorption is playing an increasingly important role on the MPs removal but the synthesis of adsorptive membrane of high capacity remains challenging. This work proposed a strategy of grafting mesoporous nanoparticles onto macroporous membranes to prepare sorbents for MPs removal. The SiO2 nanoparticles with thiol groups (SiO2-SH) was introduced onto the RC membrane surface to prepare RC-SH membrane with a hierarchical porous structure. Specific adsorptive ligands, including itaconic acid (IA) or glycidol, was then immobilized to the RC-SH membrane surface via the thio-ene and thio-epoxy chemistry towards RC-IA and RC-PG membranes. Three kinds of adsorption membranes were obtained and their physical–chemical structure and morphologies were characterized by ATR-FTIR, XPS, SEM and BET. The grafted nanoparticles have been demonstrated to increase the surface area of the adsorptive membranes. The obtained adsorptive membranes, RC-SH, RC-IA, and RC-PG, show good adsorptive capacity for Hg(II) (179.0 mg/g) , Pb(II) (140.1 mg/g), and boron (2.55 mmol/g). The adsorption isotherm and kinetics fit well with Langmuir model and pseudo-second-order kinetic model, respectively. This work provides a universal method tethering porous nanoparticles onto the macroporous membrane surface for improved functionality capacity.

Inspired by the enhancement of the desalination performance of polyamide membranes upon controlled chlorination, chlorination was applied to the polybenzimidazole (PBI) membrane hoping to improve its desalination performance. Chlorination was conducted at three pHs (4,7,10) with chlorination density up to 50,000 ppm*h via a simple soaking treatment. The structure and physicochemical changes caused by the hypochlorite treatment were characterized by SEM, AFM, XPS, FTIR and XRD. After chlorination, the morphologies did not change significantly. But the Cl element was incorporated onto polymer chains, leading to the scission of intermolecular hydrogen bond and denser packing of PBI chains. Simultaneously, the C O group emerged after chlorination, indicating ring opening of imidazole in polymer backbone. More severe damage occurs at pH 4 with more chlorine introduction, which is due to the strong oxidizability of abundant chlorine or hypochlorous acid in acid solution, while chlorination at pH 10 mostly promotes imidazole hydrolysis. Chlorination mostly alter PBI permeation properties by altering its diffusion properties, with significant enhancement of water diffusion but minimal change on salt diffusion. This result should be due to the dense packing of PBI chains. After chlorination at pH 10, the salt permeability even slightly decreased owing to the dense packed polymer chains and the electrostatic repulsion of charged membrane formed by hydrolysis. As a result, chlorination can increase the diffusion selectivity of water/salt increased by an order of magnitude, as well as the water/salt permselectivity without sacrificing the water permeability. Chlorination at basic pH especially has a positive effect on PBI membrane with improved selectivity for desalination process and sustained mechanical strength.

Sinomenine is a natural alkaloid with important biological activities (e.g. anti-cancer, anti-inflammatory, and anti-allergic). However, the unstability and short half-life absolutely limited its application to foods. Microencapsulation technology can offer a way to solve these issues. In this study, polylactic acid microcapsules loading sinomenine hydrochloride were fabricated by phase inversion emulsification-drying in liquid technique. The results showed that microcapsules had nice spherical shape, uniform particle size, and free flowing. The encapsulation efficiency was 89.2% and drug loading was 8.9% under the optimal conditions. In vitro release assays demonstrated that release of sinomenine from microcapsules was sustained and slow. Moreover, it was found that the sinomenine release fitted Fickian diffusion mechanism. The results of cytotoxicity study showed that sinomenine-loaded microcapsules were biocompatible. Sinomenine-loaded microcapsules could inhibit the growth of MDA-MB-231 cells using methyl thiazolyl tetrazolium assay. In summary, polylactide microcapsules exhibit excellent properties for sinomenine that can be used in drug or food industry.

Antifouling PVDF membranes were prepared by grafting hyperbranched polyols on the membrane surface via a three-step modification method. The membrane was first prepared by alkaline treatment to introduce alkenyl groups, then chemically immobilizing hyperbranched poly(ethyleneimine) (HPEI) on membrane surface through Michael reaction followed by ring opening reaction of the glycidol with amine groups. Chemical compositions, surface morphology and physicochemical properties of the original and modified membranes were characterized via attenuated total refection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), water contact angle (WCA) and zeta potential measurements. The antifouling property of the modified membrane was assessed by the static bovine serum albumin (BSA) and lysozyme (LZM) adsorption as well as cross-flow filtration of BSA aqueous solution. The results explicate that surface modification using hyperbranched polymers can alter membrane chemistry and morphology significantly. In contrast to the original PVDF membrane, the modified membrane shows superhydrophilic property and relatively high capability to resist nonspecific protein adsorption. Three HPEIs were used for modification and the obtained PVDFA-g-PG 60,000 membrane has a static BSA protein adsorption of 45 μg/cm 2 and shows the highest protein resistance. However, the PVDF-g-PG membrane is positively charged due to the unreacted amine groups. As a result, the PVDF-g-PG membranes also show high flux decline during the filtration of BSA aqueous solution due to the electrostatic interaction. In spite of that, the PVDF-g-PG membranes still maintain high flux recovery ratio and good washing properties.