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Surface deposition based on metal-phenolic networks (MPNs) has received increasing interest in recent years. The catechol structure is generally considered to be essential to the formation of MPNs. Our most recent results have demonstrated that some kinds of monophenols can form MPNs on substrate surfaces. Herein, we report a fast and effective surface-coating system based on the coordination of 3-(4-hydroxy-3-methoxyphenyl)-2-propenoic acid, a kind of monophenol, with Fe3+. Compared with other metal ions such as Cu2+ and Ni2+, Fe3+ with stronger electron acceptability can coordinate with the monophenol more strongly to form MPNs, and moreover, the deposition time significantly decreases to 40 min from generally 24 h. It is demonstrated that the deposition process is controlled by the coordination, Fe3+ hydrolysis, and deprotonation of the monophenol. The coatings endow substrates such as polypropylene microfiltration membrane with underwater superoleophobicity, which can be applied in oil/water separation with high separation efficiency and great long-term stability. In addition, the coated membranes are positively charged and thus are useful in selective adsorption of dyes. The present work not only provides a novel, fast, and one-step deposition method to fabricate MPNs, but also demonstrates that the fabrication efficiency of monophenol-based MPNs is comparable with that of polyphenol-based MPNs.

Mussel-inspired surface modification has received significant interest in recent years because of its simplicity and versatility. The deposition systems are still mainly limited to molecules with catechol chemical structures. In this paper, we report a novel deposition system based on a monophenol, vanillic acid (4-hydroxy-3-methoxybenzoic acid), to fabricate metal-phenolic network coatings on various substrates. The results of the water contact angle and zeta potential reveal that the modified polypropylene microfiltration membrane is underwater superhydrophobic and positively charged, showing applications in oil/water separation and dye removal. Furthermore, the single-face modified Janus membrane is promising in switchable oil/water separation. The results demonstrate a novel example of the metal-monophenolic deposition system, which expands the toolbox of surface coatings and facilitates the understanding of the deposition of phenols.

Engineering coatings with precise physicochemical properties allows for control over the interface of a material and its interactions with the surrounding environment. However, assembling coatings with well-defined properties on different material classes remains a challenge. Herein, we report a co-assembly strategy to precisely control the structure and properties (e.g., thickness, adhesion, wettability, and zeta potential) of coatings on various materials (27 substrates examined) using quinone and polyamine building blocks. By increasing the length of the amine building blocks from small molecule diamines to branched amine polymers, we tune the properties of the films, including the thickness (from ca. 5 to ca. 50 nm), interfacial adhesion (0.05 to 5.54 nN), water contact angle (130 to 40°), and zeta potential (-42 to 28 mV). The films can be post-functionalized through the in situ formation of diverse nanostructures, including nanoparticles, nanorods, and nanocrystals. Our approach provides a platform for the rational design of engineered, substrate-independent coatings for various applications.

The impact of thermal history on the kinetic response of thin thermoresponsive diblock copolymer poly(diethylene glycol monomethyl ether methacrylate)-block-poly(poly(ethylene glycol) methyl ether methacrylate), abbreviated as PMEO2MA-b-POEGMA300, films is investigated by in situ neutron reflectivity. The PMEO2MA and POEGMA300 blocks are both thermoresponsive polymers with a lower critical solution temperature. Their transition temperatures (TTs) are around 25 °C (TT1, PMEO2MA) and 60 °C (TT2, POEGMA300). Thus, by applying different temperature protocols (20 to 60 or 20 to 40 to 60 °C), the PMEO2MA-b-POEGMA300 thin films experience different thermal histories: the first protocol directly switches from a swollen to a collapsed state, whereas the second one switches first from a swollen to a semicollapsed and finally to a collapsed state. Although the applied thermal histories differ, the response and final state of the collapsed films are very close to each other. After the thermal stimulus, both films present a complicated response composed of an initial shrinkage, followed by a rearrangement. Interestingly, a subsequent reswelling of the collapsed film is only observed in the case of having applied a thermal stimulus of 20 to 40 °C. The normalized film thickness and the D2O amount of each layer in the PMEO2MA-b-POEGMA300 films are consistent at the end of the two different thermal stimuli. Hence, it can be concluded that the thermal history does not influence the final state of the PMEO2MA-b-POEGMA300 films upon heating. Based on this property, these thin films are especially suitable for the temperature switches on the nanoscale, which may experience different thermal histories.

The linear shrinkage behavior in thermoresponsive diblock copolymer films and its potential application in temperature sensors are investigated. The copolymer is composed of two thermoresponsive blocks with different transition temperatures (TTs): di(ethylene glycol) methyl ether methacrylate (MEO2MA; TT1 = 25 °C) and poly(ethylene glycol) methyl ether methacrylate (OEGMA300; TT2 = 60 °C) with a molar ratio of 1:1. Aqueous solutions of PMEO2MA-b-POEGMA300 show a three-stage transition upon heating as seen with optical transmittance and small-angle X-ray scattering: dissolution (T TT2). Due to the restrictions in the polymer chain arrangement introduced by the solid Si substrate, spin-coated PMEO2MA-b-POEGMA300 films exhibit an entirely different internal structure and transition behavior. Neutron reflectivity shows the absence of an ordered structure normal to the Si substrate in as-prepared PMEO2MA-b-POEGMA300 films. After exposure to D2O vapor for 3 h and then increasing the temperature above its TT1 and TT2, the ordered structure is still not observed. Only a D2O enrichment layer is formed close to the hydrophilic Si substrate. Such PMEO2MA-b-POEGMA300 films show a linear shrinkage between TT1 and TT2 in a D2O vapor atmosphere. This special behavior can be attributed to the synergistic effect between the restrained collapse of the PMEO2MA blocks by the still swollen POEGMA300 blocks and the impedance of chain arrangement by the Si substrate. Based on this unique behavior, spin-coated PMEO2MA-b-POEGMA300 films are further prepared into a temperature sensor by implementing Ag electrodes. Its resistance decreases linearly with temperature between TT1 and TT2.

The research on advanced functional polymers is being driven by the fast-growing demand for new functional materials that can be used in revolutionary technologies. Polymers can be endowed with functions by using certain special preparation methods or by introducing functional groups or fillers into materials. These functions are either intrinsically possessed by materials or actuated by external stimuli. In this review, we present an overview of the recent developments made in the research hotspots of functional polymers, encompassing polymerization methodologies, luminescent polymers, photovoltaic polymers, other electronic and optical polymers (including low-k polyimides and second-order nonlinear optical polymers), biorelated polymers (particularly those for biomedical applications), supramolecular polymers, stimuli-responsive polymers, shape-memory polymers, separation polymer membranes, energy storage polymers, and covalent organic framework polymers. The concepts, design strategies at the molecular level, preparation methods, classifications, properties, potential applications, and recent progress made in such polymers are summarized. Challenges and future perspectives of each type of functional polymers are also addressed, including research efforts regarding the design and fabrication of functional polymers for serving the increasing demand for new materials.

Water cut crude oil needs to be deeply dehydrated before further transportation or refining because water residuals not only tremendously increase the transportation cost and energy consumption, but also harm the oil delivery pipelines and refining equipment. Herein, we report carboxylated wood-based sponges (CWS) with underoil super-hydrophilicity for removing water residuals from crude oil. These CWS are made of aligned cellulose nanofibers after the removal of lignin and hemicellulose from natural balsa wood. Removing lignin and hemicellulose breaks the thin cell walls of balsa wood, resulting in a lamellar structure in the freeze-dried CWS. This lamellar architecture endows the CWS with high mechanical compressibility and good elastic recovery. The CWS show fast and effective dehydration for crude oil with water residuals as low as 20 ppm. The absorbed crude oil can be easily recovered from the CWS by simple squeezing. Additionally, the CWS are not only reusable without performance decline during long-term operation, but also show good chemical stability even in strong acidic and basic environments. These results indicate that the CWS have great potential for deep dehydration of crude oil, especially for water-in-crude oil emulsions.

In the present work, polydopamine nanotubes (PDA NTs) decorated with silver (Ag) nanoparticles (NPs) were successfully fabricated via a template induced self-polymerization of dopamine, followed by...

Porous surfaces have attracted tremendous interest for customized incorporation of functional agents on biomedical devices. However, the versatile preparation of porous structures on complicated devices remains challenging. Herein, we proposed a simple and robust method to fabricate "spongy skin" on diversified polymeric substrates based on non-solvent-induced phase separation (NIPS). Through the swelling and the subsequent phase separation process, interconnected porous structures were directly formed onto the polymeric substrates. The thickness and pore size could be regulated in the ranges of 5-200 and 0.3-0.75 μm, respectively. The fast capillary action of the porous structure enabled controllable loading and sustained release of ofloxacin and bovine albumin at a high loading dosage of 79.9 and 24.1 μg/cm2, respectively. We verified that this method was applicable to diversified materials including polymethyl methacrylate, polystyrene, thermoplastic polyurethane, polylactide acid, and poly(lactic-co-glycolic acid) and can be realized onto TCPS cell culture plates. This NIPS-based method is promising to generate porous surfaces on medical devices for incorporating therapeutic agents.

The deepening crisis of freshwater resources has been driving the further development of new types of membrane-based desalination technologies represented by nanofiltration membranes. Solving the existing trade-off limitation on enhancing the water permeance and the rejection of salts is currently one of the most concerned research interests. Here, a facile and scalable approach is proposed to tune the interfacial polymerization by constructing a calcium alginate hydrogel layer on the porous substrates. The evenly coated thin hydrogel layer can not only store amine monomers like the aqueous phase but also suppress the diffusion of amine monomers inside, as well as provide a flat and stable interface to implement the interfacial polymerization. The resultant polyamide nanofilms have a relatively smooth morphology, negatively charged surface, and reduced thickness which facilitate a fast water permeation while maintaining rejection efficiency. As a result, the as-prepared composite membranes show improved water permeance (~30 Lm−2h−1bar−1) and comparable rejection of Na2SO4 (&gt, 97%) in practical applications. It is proved to be a feasible approach to manufacturing high-performance nanofiltration membranes with the assist of alginate hydrogel regulating interfacial polymerization.

The performances of lithium-ion batteries (LIBs) are dependent on the wettability and stability of porous separators. Musselinspired coatings seem to be useful to improve the surface wettability of commercialized polyolefin separators. However, it is still a challenge to guarantee their stability under polar electrolytes. Herein, we report a facile and versatile way to enhance the wettability and stability of polypropylene separators by constructing robust polydopamine (PDA) coatings triggered with CuSO4/H2O2. These coatings were conveniently deposited on the polypropylene separator surfaces and the PDA-coated separators exhibited the improved surface wettability and thermal stability. The electrolyte uptake increased nearly two folds from the pristine separator to the modified ones. Correspondingly, the ionic conductivity also rose from 0.82 mS·cm-1 to 1.30 mS·cm-1. Most importantly, the CuSO4/H2O2-triggered PDA coatings were very stable under strong polar electrolytes, endowing the cells with excellent cycle performance and enhanced C-rate capacity. Overall, the results unequivocally demonstrate that application of PDA coatings on polyolefin separator triggered by CuSO4/H2O2 is a facile and efficient method for improving the wettability and stability of separators for high LIBs performance.

Surface-mediated transfection has drawn tremendous interest for gene therapy due to its localized gene delivery characteristic and promising perspective for combination devices in clinical applications. However, a method for the controllable load of genetic agents and tunable transfection efficiency to primary cells remains unsatisfactory. Herein, we present a polymeric spongy film with modification of polydopamine (PDA) for controlling load of plasmid DNAs and improving transfection to primary endothelial cells. We demonstrate that, via wicking action, the loading of DNA into the film is simple, rapid, and highly controllable while easily reaching ∼95 μg/cm

Deposition of dopamine and tannic acid has received great attention in the fields of surface and interface science and technology. The deposition behaviors of various metal–phenolic systems have been investigated, and it is generally accepted that at least one catechol group is essential to the formation of the coatings. Herein, we report a novel and effective surface-coating system based on the coordination complexes of FeIII ions with a natural product juglone that contains only one phenolic hydroxyl. We investigated the deposition behaviors of this novel system on various substrates. Microporous polypropylene membrane modified with juglone/FeIII coatings is superhydrophilic and underwater superoleophobic, showing high separation efficiency and good reusability for various oil/water emulsions. In addition, the modified membrane can adsorb anionic dyes and selectively remove them from dye mixtures with high efficiency. We further demonstrated that the coating is a result of the synergetic effect of juglo...

Nanomaterials and nanotechnologies have been expected to provide innovative platforms for addressing antibacterial challenges, with potential to even deal with bacterial infections involving drug-resistance. The current review summarizes recent progress over the last 3 years in the field of antibacterial nanomaterials with a photothermal conversion effect. We classify these photothermal nanomaterials into four functional categories: carbon-based nanoconjugates of graphene derivatives or carbon nanotubes, noble metal nanomaterials mainly from gold and silver, metallic compound nanocomposites such as copper sulfide and molybdenum sulfide, and polymeric as well as other nanostructures. Different categories can be assembled with each other to enhance the photothermal effects and the antibacterial activities. The review describes their fabrication processes, unique properties, antibacterial modes, and potential healthcare applications.

Nanofilms are of great interest as a kind of separation membranes for seawater desalination and wastewater treatment. Their fabrication, however, always needs a time-consuming process and shows low atom economy. Herein, we report pyrogallol/polyethyleneimine (PG/PEI) nanofilms spontaneously formed at the gas/liquid interface within ten minutes and composited on microporous substrates. Both the film thickness and the surface charge are facilely adjusted by the reaction time and the mass ratio of PG/PEI in aqueous solution. The solution is repeatedly used to fabricate the nanofilm composite membranes and thus this method is with high atom economy of raw materials. The as-prepared nanofilm composite membranes can be directly applied in aqueous nanofiltration, showing a relatively high water permeation flux (17.5 L m−2 h−1 bar−1) and salt rejection (>94% for MgCl2) during a long-term operation. The nanofilms are also demonstrated potentials in organic solvent nanofiltration after moderate cross-linking by glutaraldehyde.

There is an increasing demand for anti-oil materials applicable in the efficient separation of crude oil from oil-in-water emulsions and oil/water mixtures for oily water treatment and oil spill remediation. Most of the reported superhydrophilic materials are able to repel model oils, but are still easy to be adsorbed and fouled by crude oil with high viscosity and strong adhesive properties. Herein, we report cellulose nanocrystals (CNCs) for fabricating nanopapers and nanocoatings with high anti-crude oil characteristics. These CNCs are composed of cellulose chains densely and rigidly arranged in a crystalline state, which rigorously restricts the motions of the hydrophilic groups on the material surfaces. They show more stable water binding affinity and lower underwater adhesive force than other super-hydrophilic materials. Therefore, the nanopapers and nano-coatings are capable of eliminating oil contamination from their surfaces not only in the water-wetted state, but also in the dry state. The nanopapers fabricated by vacuum-filtration can effectively separate surfactant-stabilized crude oil-in-water emulsions. The meshes assembled with nanocoatings are useful for the separation of crude oil/water mixtures with an extremely high water flux up to 35 000 L m−2 h−1. Meanwhile, the CNC-based nanomaterials show excellent anti-crude oil properties, no water flux decline, good pH stability and high salt resistance. All these characteristics make them potentially applicable to the remediation of crude oil spills on offshore seawater.

Grain boundaries widely exist in 2-D materials, and they are often considered as defects harming the physicochemical properties of materials. Here, we report unclonable anti-counterfeiting films ba...

Polymerization at the liquid–liquid interface has attracted much attention for synthesizing ultrathin polymer films for molecular sieving. However, it remains a major challenge to conduct this process outside the alkane–water interface since it not only suffers water‐caused side reactions but also is limited to water‐soluble monomers. Here, we report the interfacial polymerization at the alkane/ionic liquid interface (IP@AILI) where the ionic liquid acts as the universal solvent for diversified amines to synthesize task‐specific polyamide nanofilms. We propose that IP@AILI occurs when acyl chloride diffuses from the alkane into the ionic liquid instead of being triggered by the diffusion of amines as in the conventional alkane–water system, which is demonstrated by thermodynamic partitioning and kinetic monitoring. The prepared polyamide nanofilms with precisely adjustable pore sizes display unprecedented permeability and selectivity in various separation processes., Interfacial polymerization at the alkane/ionic liquid interface has been designed. The extendibility, designability, and controllability brought by the ionic liquid replace the instability and low solubility caused by water in conventional polymerization. The polyamide nanofilms synthesized at the new delicate water‐insoluble monomer interfaces possess adjustable pore size and exhibit unprecedented performance in various separation applications.

Organic solvent nanofiltration (OSN) is regarded as a promising separation technology in chemical and pharmaceutical industries. However, it remains a great challenge in fabricating OSN membranes with high permeability and precise selectivity by simple, transfer-free, and up-scalable processes. Herein, we report lysozyme nanofilm composite membranes (LNCM) prepared by one-step methods with hydrophobic substrates at the air/water interface. The microporous substrates not only promote the heterogeneous nucleation of amyloid-like lysozyme oligomers to construct small pores in the formed nanofilms but also benefit for the simultaneous composition of LNCM via hydrophobic interactions. The constructed nanopores are reduced to around 1.0 nm, and they are demonstrated by grazing incidence small-angle X-ray scattering with a closely packed model. The LNCM can tolerate most organic polar solvents and the permeability surpasses most of state-of-the-art OSN membranes.

Porous materials have attracted great interest in recent years, and a variety of surface modification methods have been developed to endow porous materials with multifunctional applications. Herein, multifunctional porous materials are fabricated based on surface metallization. Metallized sponges with Ag and Cu are highly hydrophobic and are still hydrophobic under oil. The metallized sponges selectively adsorb oils from oil/water mixtures and can completely remove oils from water. We further demonstrate continuous oil-water separation by the metallized sponges with the aid of a peristaltic pump. The Ag-metallized materials show high catalytic performance for both chemical reduction and dye degradation. The catalytic reduction efficiency of 4-nitrophenol reaches 97.7% within 60 min and remains as high as 96% after 15 cycles. Moreover, the metallized materials show 99.99% bactericidal efficiency for both Staphylococcus aureus and Escherichia coli. Particularly, the Cu-metallized materials exhibit stable conductivity under deformation; and metal patterns are realized via the metallization method combined with a patterned mask, which may provide a feasible approach for flexible electronics. This work provides a versatile method to introduce metal coatings to porous materials, broadening the applications of porous materials.

Novel thin film composite forward osmosis (TFC-FO) membranes were developed by using hydrophilic cellulose triacetate (CTA) porous substrates prepared by thermally induced phase separation (TIPS) method. A series of CTA substrates with different structures were fabricated to demonstrate the structure-performance relationship of the TFC-FO membranes. It is found that the substrates possess relatively large pores on their rough surfaces as well as their intrinsic hydrophilicity, leading to intensively large “ridge-and-valley” structures on the TFC-FO membranes. The large surface pores of the CTA substrates result in thick and rough polyamide skin layers. Moreover, the optimal CTA porous substrates should have a small thickness, high porosity, and oriented plate-like pores. These structures profit the TFC-FO membranes with superior water permeability, relatively high salt rejection, and low structural parameter. The one with thickness of 102 ± 16 μm and porosity of 87.1 ± 1.1% shows the smallest structural parameter (516 μm) and the desirable over-all properties in terms of water permeability and selectivity. It means that the hydrophilic CTA porous substrates enable to alleviate the internal concentration polarization (ICP) effect. These TFC membranes could provide a new route to develop high-performance composite membranes for FO desalination.

Safety and electrochemical performance are key concerns for porous separators used in Li-ion batteries. We demonstrate the potential application of a sandwich-structured composite separator (SSCS) for highly safe Li-ion batteries, which is comprised of a poly(vinylidene fluoride) (PVDF) porous bulk and a trapped polyethylene terephthalate (PET) nonwoven fabrics layer. The as-prepared SSCS possesses an anisotropic porous structure with large inner pores while small surface ones arising from a nonuniform cooling process along the thickness direction during thermally induced phase separation. The distinctive structure of SSCS gives rise to excellent properties concerning security, such as electrolyte retention, mechanical strength, thermal stability and thermal-shutdown ability. Furthermore, the higher ionic conductivity as well as lower interfacial impedance of SSCS endows the resulting LiFePO4/Li battery with enhanced discharge capacity and cycle stability compared to the cell assembled by the commercialized Celgard 2400 separator. Therefore, the SSCS is expected to be a promising candidate for Li-ion batteries with high cell performances and enhanced safety.

The architecture of polymers plays a crucial role in self-assembly processes. However, the effect of end groups is still not understood thoroughly in many processes including the breath figure method, which is effective for preparing patterned porous films. Herein, we synthesized a series of well-defined cyclic polystyrenes by the combination of atom transfer radical polymerization and azide–alkyne click cyclization and investigated the self-assembly behaviors. The corresponding linear polymers were also compared. Results indicate that polar end groups dramatically improve the regularity of the self-assembled films. For cyclic polystyrenes without any end group, the ability to form patterned porous films is between two groups of linear samples. On the one hand, the results confirm the effect of polar end groups in the breath figure method. On the other hand, the impact of cyclic topology is also verified. This work reveals the nature of stabilization of templating droplets via the polymers by the measurem...

Bioinspired polyphenol/polyamine codeposition has been demonstrated by the competence for surface modification; however, the reaction processes including mechanism and kinetics remain superficially understood. In this work, the catechol (CA)-amine reaction has been thoroughly investigated by using CA and two amines m-phenylenediamine and piperazine. We verify that both primary and secondary amines are prone to link with CA through Michael addition to form polyphenol/polyamine oligomers under aerobic and mild-alkaline conditions. Molecular simulations indicate that the Michael addition products are dominant for both aromatic and aliphatic amines with CA, which supports the durable chem- and phystability of the codeposited coatings. The aggregation kinetics of polyphenol/polyamine is provided for the first time, and the formed aggregates show high-adhesive properties, which can be deposited as the skin layers for high-performance nanofiltration membranes.

Large-scale fabrication of nanofilms directly on macro-porous substrates remains a major challenge in preparing advanced separation membranes. In this work, polyphenol/polyamine nanofilms with a minimum thickness around 13 nm were formed at the gas/liquid interface and simultaneously composited onto hydrophobic macro-porous substrates with the pore size of several hundreds of nanometers, a process driven by high oxygen concentration and interfacial energy at the interface. The as-prepared nanofilms show nearly complete rejection to a wide spectrum of dye molecules, and above 90% rejection to divalent cations such as Mg2+ and Ca2+ with a relative high permeate flux above 15 L m−2 h−1 bar−1, demonstrating great potential in ionic and molecular sieving processes.

Nanocomposite membranes (NCMs) provide inspiration to combine the superiorities of inorganic nanomaterials and polymeric matrices for outstanding nanofiltration performance. Herein, novel NCMs have been fabricated via co-deposition of polydopamine (PDA), polyetheylenimine (PEI) and electropositive gold nanoparticles (GNPs) followed by crosslinking. The GNPs distribute in the formed selective layer uniformly without obvious aggregation due to their good dispersion and compatibility with the positively charged PDA/PEI matrix. Thus the selective layer remains defect-free and the surface potential is enhanced by the positively charged GNPs. These endow the NCMs with high retention ratio (> 90%) for bivalent cations, such as Mg 2+ , Ca 2+ , and various heavy metal ions. Meanwhile, the permeate flux of the NCMs doubles compared with the PDA/PEI co-deposited nanofiltration membranes (NFMs) attributed to the hydrophilicity of the embedded GNPs and the loosened selective layer structures. The compact resistance and the structural stability of the NCMs are also improved effectively in contrast with the PDA/PEI ones, which are of significant importance for the practical use of NFMs. Moreover, the quaternary amine moieties on GNPs improve the antibacterial activity of NCMs against S. aureus and E. coli .

Loose nanofiltration membranes (LNMs) have attracted increased attention in the field of sustainable management of the highly-saline textile wastewater. Remained challenges include achieving efficient dye/salt fractionation and alleviating high fouling propensity. Herein, functionalized-LNMs (F-LNMs) are developed by the co-deposition of polyethylenimine and tannic acid, followed by the assembly of ferric ions (Fe(III)) and organophosphonic acid (OPa) for antifouling surface construction. Plentiful OPa groups are immobilized onto the membrane surface via the high surface binding affinity and the strong coordination bonding of Fe(III) as ‘bridge’ linkers. The superior hydrophilicity and large steric hindrance of these OPa groups endow the F-LNMs with notably improved antifouling property against organic dye clusters. The optimized F-LNMs show significantly increased membrane permeance (10–30 L m−2 h−1·bar−1) in treating those simulated dye/salt aqueous solutions containing 1.0 g L−1 dye and 80.0 g L−1 Na2SO4. They also exhibit high salt permeation (>94%) and acceptable dye rejection (overall >93%) of Congo red, methyl blue and three hydrolyzed reactive dyes. Furthermore, the direct reuse of Na2SO4 from the actual dyeing effluent is achieved by combining membrane separation and activated carbon adsorption, revealing the promising application prospects of F-LNMs in managing highly-saline textile wastewater.

Slippery lubricant-infused porous surfaces (SLIPSs) hold great promise in fields requiring adhesion resistance such as self-cleaning, anti-fouling, anti-icing, and anti-scaling. However, their road to practical application is still blocked by the complicated fabrication process and the restricted coating area. To address these challenges, we propose a new concept of endogenous SLIPS in which the porous structure grows from the solution coating of polypropylene/caprylyl methicone undergoing a thermally induced phase separation (TIPS) process. Caprylyl methicone serves as the diluent during TIPS as well as the lubricant in the SLIPS so that the coating can be fabricated in one step and unrestrictedly. The dissolution and phase separation mechanisms have been revealed by molecular dynamic simulation and in situ microscopic observation. Such SLIPSs exhibit impressive sliding property even for sticky and viscous liquids and exhibit extremely low ice adhesion in anti-icing tests.

Separation membranes are urgently desired for the efficient recovery of oil-like ionic liquids (ILs) from industrially applied emulsions. Conventional membranes with asymmetric porous structure and high tortuosity suffer from high trans-membrane resistance and low mass transfer efficiency for this application. Herein, Janus membranes (JMs) are constructed by the single-side modification of hydrophobic poly(vinylidene fluoride) (PVDF) membrane with vertically penetrative pores for the rapid-mass-transfer separation of viscous ILs. A charged and underwater IL-phobic thin layer is facilely co-deposited on one side of the PVDF membranes from polydopamine/poly(diallyldimethylammonium chloride) solution. This single-side modification endows the as-prepared JMs with a deemulsification function to IL-in-water emulsions and a unidirectional transportation ability to hydrophobic ILs. These JMs show an excellent IL recovery capacity with high permeation speed and stable flux during a long-term cyclic separation of IL-in-water emulsions because the vertically penetrative pores with low tortuosity allow to significantly reduce the trans-membrane resistance toward those viscous ILs. Overall, our vertically-channeled JMs provide an ideal material solution for recovering high-viscosity and value-added chemicals from their industrial water mixture in practice, especially from those aqueous emulsions.

Biofouling control is a major task in membrane separation processes for water treatment and biomedical applications. In this work, N -alkylated polyethylenimine (PEI) is facilely and efficiently introduced onto the membrane surfaces via the co-deposition of catechol (CCh) and PEI, followed by further grafting of PEIs (600 Da, 70 kDa and 750 kDa) and cationization with methyl iodide (CH 3 I). The physical and chemical properties of the constructed membrane surfaces are characterized with scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, zeta potential and water contact angle measurements. Antibacterial assay reveals that the optimized membrane surfaces possess around 95% antibacterial efficiency against Gram-positive Staphylococcus aureus ( S. aureus ) with weak adhesion of bacteria cells after 24 h of bacterial contact. Additionally, the membrane surfaces also exhibit much enhanced antifouling property during the filtration of opposite charged bovine serum albumin (BSA). These results demonstrate a useful strategy for the surface modification of separation membranes by a kind of antimicrobial and antifouling coating.

Surface modification has been well recognized as a promising strategy to design and exploit diversified functional materials. However, conventional modification strategies usually suffer from complicated manufacture procedures and lack of universality. Herein, a facile, robust, and versatile approach is proposed to achieve the surface functionalization using dopamine and acrylate monomers via a one-step polymerization and codeposition process. The gel permeation chromatography, proton nuclear magnetic resonance, liquid chromatography-mass spectrometry, and UV-visible spectra results indicate that dopamine possesses the capability of triggering the polymerization of acrylate monomers into high-molecular-weight products, and the inherent adhesive ability of polydopamine can assist the polymerized products to deposit on various substrates. Besides, protein-resistant, antibacterial, and cell adhesion-resistant surfaces can be easily fabricated via the finely designed integration of corresponding acrylate monomers into the codeposition systems. This approach of in situ polymerization and codeposition significantly simplifies the fabrication process and provides more manifold choices for surface modification, which will open a new door for broadening the applications of polydopamine-based coatings.

Porous separators are key components for lithium-ion batteries (LIBs) and they have drawn considerable attention because of their vital role in governing battery cost and performance (e.g., power density, safety, and longevity). Here, zirconia-coated separators were fabricated via a facile biomineralization process with the aim to improve the performance of commercialized polypropylene separators. The as-prepared organic-inorganic composite separators show excellent thermal stability, even at the melting temperature (160 °C) of polypropylene. This is due to the well-distributed zirconia coatings on the separator surfaces. Furthermore, the interfacial impedance of the composite separators is only 343.8 Ω, which is four times lower than the pristine polypropylene ones. The results demonstrate an attractive method to prepare organic-inorganic composite separators with outstanding properties, which makes them promising candidates for high-performance LIBs.

Polysulfone (PSF) membranes have gained great attention in the fields of ultrafiltration, microfiltration, and thin film composite membranes for nanofiltration or reverse osmosis. For the first time, it is proposed to fabricate PSF membranes via thermally induced phase separation (TIPS) process using diphenyl sulfone (DPSO2) and polyethylene glycol (PEG) as mixed diluent. DPSO2 is chosen as a crystallizable diluent, while PEG is considered in terms of molecular weight (M w) and dosage. We systematically investigate the interactions between PSF, DPSO2 and PEG based on the simulation calculations and solubility parameter theory. It is inferred that DPSO2 has an excellent compatibility with PSF, and the addition of PEG results in the ternary system thermodynamically less stable and then facilitates its liquid-liquid (L-L) phase separation. SEM images indicate that cellular-like pores are obvious throughout the membrane when the PEG content in the mixed diluent is 25 wt%−35 wt%. We can facilely manipulate the pore size, water flux and mechanical properties of PSF membranes with the dosage of PEG-200, the M w of PEG or the cooling rate. The successful application of TIPS can provide a new approach for structure manipulation and performance enhancement of PSF membranes.

A Janus membrane with opposing wettability was first reported with both function of water-to-oil and oil-to-water emulsification. This membrane is conveniently fabricated by single-surface deposition of polydopamine/polyethylenimine (PDA/PEI). The asymmetric wettability can also reduce the transmembrane resistance during the process, indicating an economical and promising strategy to prepare various emulsions. This research opens a novel avenue for exploring and understanding the Janus membrane, and provides a perspective to design the asymmetric membrane structures with promoted performance in conventional membrane processes.

Directed self-assembly (DSA) of block copolymers (BCPs) combines advantages of conventional photolithography and polymeric materials and shows competence in semiconductors and data storage applications. Driven by the more integrated, much smaller and higher performance of the electronics, however, the industry standard polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) in DSA strategy cannot meet the rapid development of lithography technology because its intrinsic limited Flory–Huggins interaction parameter (χ). Despite hundreds of block copolymers have been developed, these BCPs systems are usually subject to a trade-off between high χ and thermal treatment, resulting in incompatibility with the current nanomanufacturing fab processes. Here we discover that polystyrene-b-poly(propylene carbonate) (PS-b-PPC) is well qualified to fill key positions on DSA strategy for the next-generation lithography. The estimated χ-value for PS-b-PPC is 0.079, that is, two times greater than PS-b-PMMA (χ = 0.029 at ...

Mussel-inspired polydopamine (PDA) coatings have been broadly exploited for constructing functional membrane surfaces. One-step codeposition of PDA with antifouling polymers, especially zwitterionic polymers, has been regarded as a promising strategy for fabricating antifouling membrane surfaces. However, one challenge is that the codeposition is usually a slow process over 10 h or even several days. Herein, we report that CuSO4/H2O2 is able to notably accelerate the codeposition process of PDA with poly(sulfobetaine methacrylate) (PSBMA). In our case, PSBMA is facilely anchored to the polypropylene microporous membrane (PPMM) surfaces within 1 h with the assistance of PDA because of its strong interfacial adhesion. The PDA/PSBMA-coated PPMMs show excellent surface hydrophilicity, high water permeation flux (7506 ± 528 L/m2·h at 0.1 MPa), and an outstanding antifouling property. Moreover, the antifouling property is maintained after the membranes are treated with acid and alkali solutions as well as organ...

The fluorescent properties of a linear poly(hydroxyurethane) (P1) from carbon dioxide, siloxane (Si–O–Si)-containing bisepoxide and diamine are described. P1 showed strong photoluminescence with a quantum yield of up to 23.6%, high photostability, and broad absorption and emission spectra either in bulk or solution. The flexibility and hydrophobicity of the Si–O–Si linkage in P1 were utilized to drive the intense aggregation of hydroxyurethane chromophores which combined with the hydrogen bonding interactions lead to strong photoluminescence. P1 was used as a single phosphor film for fabricating a low voltage, cool white light-emitting diode device with competitive performances.

The molecular weight distribution (MWD) of polymers shows effects on their phase separation, crystallization, self-assembly, and mechanical properties. It is well known that the architecture of polymers plays a crucial role in the self-assembly of patterned porous films via the breath figure method. However, the effect of MWD is still unknown. In this work, we synthesized a series of hydroxyl-end-functionalized polystyrenes with a narrow MWD by atom transfer radical polymerization (ATRP). MWD was further broadened by mixing the polystyrenes. Honeycomb-patterned porous films were prepared from the polystyrenes. For a unimodal distributed sample with a wide MWD, the optimal concentration for patterned film formation is expanded. However, an improvement cannot be observed in bimodal distributed polymers. The high heterogeneity of the bimodal system weakens the cooperation of components with different molecular weights in stabilizing water droplets. Furthermore, it is interesting to note that the stiffness of patterned porous films can be enhanced by tuning the MWD. The present study demonstrates the effects of the MWD of polymers on the self-assembly behaviors, providing new insights into the breath figure process and the design of robust patterned porous films.

Nanofiltration membranes are of great interest in brackish water desalination and drinking water purification. Improving the permeation and separation performance remains a big challenge in advanced nanofiltration membranes. Herein, we report triple-layered composite nanofiltration membranes constructed by the interfacial polymerization of diamine and acyl chloride on a cellulose nanocrystal interlayer supported by a microporous substrate. The cellulose nano-crystal interlayer plays a crucial role in the polyamide skin layer formation and the following nanofiltration process. It can store aqueous diamine monomers and slow down the interfacial polymerization for a relatively low cross-linking degree of the skin layer. This hydrophilic interlayer also facilitates water permeation through a “dragging effect”. The constructed membranes exhibit an ultra-high permeation flux up to 204 L m−2 h−1 under 0.6 MPa with a Na2SO4 rejection above 97%, which is the highest reported result to our knowledge. The ultra-high water permeation flux enables nanofiltration at low operating pressure, making it an energy-saving process. Moreover, the low cross-linking degree of the skin layer results in a high monovalent/divalent ion separation ratio.

PVDF/PAN blend porous membranes were prepared via thermally induced phase separation (TIPS) and used as separators for lithium ion batteries. TIPS behavior was investigated in detail to control the morphology, pore size, porosity, and mechanical properties of the blend separators as a function of PAN content. Rod-like pores are the typical structure resulted from solid−solid phase separation, while the pore size and porosity decrease with an increase of PAN in the blend. The introduction of PAN enhances the tensile strength and the thermal stability of the blend separator. The electrolyte uptake and the ionic conductivity reduce correspondingly with the decrease of the pore size and the porosity. However, the graphite/polymer electrolyte/LiFePO4 batteries with the blend separators exhibit higher C-rate performance, and better reversible charge/discharge cycle stability than those with PVDF separators and the commercial Celgard 2400.

Nanofiltration membranes (NFMs) with a high water permeation flux and salt rejection are extremely desirable due to their low energy consumption and superior separation efficiency in practical appl...

Enhanced capabilities of stain removal and comfort control are simultaneously achieved by the light and thermo dual-responsive copolymer poly(triethylene glycol methyl ether methacrylate- co-ethylene glycol methacrylate- co-acrylamide azobenzene) (P(MEO3MA- co-EGMA- co-AAAB)) cross-linked on cotton fabrics. P(MEO3MA- co-EGMA- co-AAAB) is synthesized by sequential atom transfer radical polymerization with a molar ratio of 8 (MEO3MA):1 (EGMA):1 (AAAB). The MEO3MA units induce a thermoresponsive behavior to the copolymer. The hydrophilicity of the copolymer films can be further improved by the light-induced trans- cis isomerization of the AAAB units with UV radiation. The copolymer is facilely immobilized onto cotton fabrics with 1,2,3,4-butane tetracarboxylic acid as cross-linker. Due to the immobilization of P(MEO3MA- co-EGMA- co-AAAB), the hydrophilicity of the fabric surface is increased under UV radiation. Therefore, by simply installing a UV light source in the washing machine, better capability of stain removal is realized for the cross-linked cotton fabrics. It can prominently reduce the consumption of energy, water, and surfactants in laundry. In addition, the trans-AAAB units of the copolymer cause the cross-linked P(MEO3MA- co-EGMA- co-AAAB) layer to be more hydrophobic under ambient conditions. Hence, the copolymer can more easily collapse and form a porous structure on the fabrics. Thus, the air permeability of cotton fabrics cross-linked with P(MEO3MA- co-EGMA- co-AAAB) is enhanced by 13% at human body temperature as compared to P(MEO3MA- co-EGMA), giving improved comfort control during daily wear.

Sponges are open cellular materials with numerous interesting features. However, the potential of compartmentalized sponges has not been explored although many new properties and applications could be envisioned. We found that compartmentalized fibrous ultraporous polymer sponges with superhydrophobic surfaces could be designed as virtually wall-less reaction containers. With this, for example, the efficient removal of CO 2 from water and the controlled mineralization of calcium carbonate are possible. The high porosity (>99%) and superhydrophobicity make these sponges ideal candidates to hold alkanolamine solution for absorbing CO 2 and exchange gas through the walls of the sponges. The tubular sponge exhibits a much higher evaporation rate than a glass tube with the same diameter due to the much larger contact area between water and air. Therefore, the spongy reaction container also possesses a much faster adsorption rate, smaller equilibration time and higher efficiency for CO 2 adsorption than the glass tube container. In addition, these tubular sponges are also utilized to precipitate calcium carbonate by ammonium carbonate decomposition, which can control the deposition rates and products by tailoring the porosity and surface chemistry in the future. These new sponges provide an ideal basis for numerous new applications, for example, as breathable pipe lines for gas-liquid exchange, slag slurry carbonization, humidifier, and blood enricher.

Homoporous membranes fabricated by self-assembled block copolymers (BCPs) have gained growing attention for their easy availability of well-ordered nanostructures for precise separation. However, it remains a challenges to improve the mechanical integrity, hydrophilic properties, and pore functionalities of the existing systems. To this end, we report an organic-mineral composite hybrid nanoporous BCP membrane with attractive superhydrophilicity, mechanical stability, and fouling-resistance derived from a bioinspired block copolymer, poly(propylene carbonate)- block-poly(4-vinylcatechol acetonide) (PPC- b-PVCA). The key advances include the following. (1) The PPC minor block is qualified as sacrificial domain because of its alkali sensitivity for generating monodisperse nanopores. (2) The PVCA matrix block contains the catechol groups, which enables the formation of inorganic layer via a biomineralization process, thus producing an organic-mineral composite nanoporous BCP membrane with attractive superhydrophilicity, mechanical stability, and fouling resistance. A ∼200 nm thickness BCP film with monodisperse through-pores of 12 nm diameter cylinders oriented perpendicularly to a supporting microfiltration membrane is fabricated by sequential blade-casting, solvent annealing, hydrolysis sacrificial block, and biomineralization process. The mechanical stability, high water flow (114 L m

Separation membranes with switchable wettability show great potential in the efficient treatment of both oil-in-water and water-in-oil emulsions. There still remain some critical challenges to prepare these membranes by a facile procedure and to elucidate the wettability response mechanism reasonably. Herein, commercial polypropylene membranes are endowed with switchable surface wettability by a simple co-deposition method of tannic acid and diethylenetriamine. The as-fabricated membrane surfaces are hydrophilic due to water immersion but hydrophobic after ethanol treatment. This hydrophilicity-hydrophobicity translation can repeat cyclically by water/ethanol treatments without losing the surface wettability. DFT simulations are used to calculate the solvation free energies of tannic acid in water and ethanol, respectively, to illustrate the chemical mechanism of the hydrophilicity-hydrophobicity translation. The results are in accordance with UV–vis spectra of the polyphenol in both solvents. The wettability switchable membranes show great potential in separating both oil-in-water and water-in-oil emulsions with excellent efficiency (98%). Moreover, the driving force for the separation processes can be an applied pressure of 0.1 MPa or merely the gravity of emulsions.

It is essential to develop portable, versatile, and reliable diagnostic devices in point-of-care testing (POCT). The detection of biomarkers requires selective separation and large specific surface for high sensitivity and accuracy at trace levels in whole blood samples using POCT devices. Herein, a kind of 3D electrochemical biosensors were designed via in-situ synthesizing polyaniline (PANI) and platinum nanoparticles (Pt NPs) on polysulfone hollow fiber membrane (HFM) scaffolds with gradient porous structure. The gradient porous HFMs scaffolds provide uniform capillary flow, self-driven blood separation and sufficient enzyme immobilization sites. Simultaneously, the in-situ deposited materials fulfill interconnected conductive networks, thus ensuring accurate and rapid detection of the sensors without hindering capillary progress. These sensors display ultralow sampling (~3 μL), fast fluid flow (>1 μL/ms), wide linear range (glucose: 0–24 mM, R2=0.992; cholesterol: 0–9 mM, R2=0.999), high sensitivity and accuracy especially under different hematocrits in POCT applications towards glucose and cholesterol. The innovative integration of POCT biosensors with interconnected conductive nanoparticles, selective blood separation and gradient porous structures can find wide application in resource-limited regions, large population screening, and public health emergencies.

Polyamide composite membranes are still required to promote their structure uniformity and desalination performance. Herein, a vacuum-assisted strategy was used to deal with this challenge by improving the distribution homogeneity of diamine monomer in porous substrates for typical interfacial polymerization. Laser scanning confocal microscope analyses demonstrate that the piperazine solution can be adsorbed in the microporous substrates with a very homogeneous and stable way. This uniform diamine distribution shows great advantages for synthesizing the selective layers of polyamide on the substrate surfaces via the interfacial polymerization of piperazine and trimesoyl chloride. The as-prepared polyamide layers with a circular size of 30 cm exhibit uniform structures including thickness less than 20 nm, cross-linking degree up to 100%, surface roughness lower than 20 nm and pore diameter about 0.41 nm. Therefore, the polyamide composite membranes present nanofiltration performances of ultrahigh rejection above 99.6% to Na2SO4 and high water permeability of 20 L/m2 h bar. These membranes also show a promising selectivity for NaCl/Na2SO4 up to 196, which is higher than most of the commercial and the reported nanofiltration membranes in recent years.