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A donor–acceptor polymer with broad absorption from 300 to 1700 nm as a photothermal material toward highly efficient solar-driven water evaporation.

Oil/water separation by porous materials has received growing interest over the past years since the ever-increasing oily wastewater discharges seriously threaten our living environment. Purification of nano-sized and concentrated emulsions remains a big challenge because of the sharp flux decline by blocking the pores and fouling the surfaces of those porous materials. Herein, we propose a solar-driven evaporator possessing thin-film-composite architecture to deal with these two bottlenecks. Inspired by plant roots, our evaporator composes of a large-pore sponge wrapped by a thin hydrogel film, which is constructed by the contra-diffusion and cross-linking of alginate and calcium ions at the sponge surface. The dense superoleophobic hydrogel layer serves as a selective barrier that prevents oil emulsions but allows water permeation, while the inner sponge with large pores facilitates water transport within the evaporator, ensuring sufficient water supply for evaporation. By splitting the single evaporator into an array, the evaporator performs a high evaporation rate of ∼3.10 kg·m

Thin-film-composite (TFC) nanofiltration membranes have found wide uses in environment remediation and industrial separation. There is a growing trend to avoid the use of organic solvents and toxic chemicals during membrane fabrication. Therefore, the aqueous fabrication of TFC membranes receives considerable interest as a green and sustainable process. However, it remains challenging to construct a defect-free and ultrathin film in a homogeneous aqueous phase without the assistance of an interface. The contra-diffusion process provides a special "interface" to confine the film formation within a narrow space by regulating the competition between precursor diffusion and interfacial reactions. Herein, Fe

Immobilization of metal nanoparticles (NPs) on flexible substrates for surface-enhanced Raman scattering (SERS) has received great attention. Anchoring NPs on substrates generally involves the process of surface modification, thanks to its simple, universal, and nondestructive features. 2-Hydroxy-1,4-naphthoquinone (HNQ), a plant-derived compound used to dye hairs and nails, may interact with polyamine or metal ions to form a surface coating. Here, we report the formation of amino-quinone coatings via the co-deposition of HNQ and polyethyleneimine, which provides a functionalized platform to rapidly immobilize Ag NPs on substrates such as a poly(dimethylsiloxane) (PDMS) film to fabricate Ag-PDMS substrates for SERS detection. The detection concentrations are down to 10

The proposal of the aggregation-induced emission (AIE) effect shines a light on the practical application of luminescent materials. The AIE-active luminescence microgels (TPEC MGs) with photo-induced color-changing behavior were developed by integrating positively charged AIE luminogens (AIEgens) into the anionic network of microgels, where AIEgens of TPEC were obtained from the quaternization reaction between tetra-(4-pyridylphenyl)ethylene (TPE-4Py) and 7-(6-bromohexyloxy)-coumarin. The aqueous suspensions of TPEC MGs exhibit a significant AIE effect following the enhancement of quantum yield. In addition, further increase in fluorescence intensity and blueshift occur at elevated temperatures due to the collapse of microgels. The distinctive photochromic behavior of TPEC MGs was observed, which presents as the transition from orange-yellow to blue-green color under UV irradiation, which is different from TPEC in good organic solvents. The phenomenon of color changing can be ascribed to the competition between photodimerization of the coumarin part and photocyclization of TPE-4Py in TPEC. The photochromic TPEC MG aqueous suspensions can be conducted as aqueous microgel inks for information display, encryption, and dynamic anticounterfeiting.

This review focuses on end-functionalized polymers synthesized by controlled/living radical polymerizations and the applications in fields including bioconjugate formation, surface modification, topology construction, and self-assembly.

A Janus evaporator featuring a “moving interface” is developed. The photothermal layer shows a reversible wettability transition from the daytime to the night, performing excellent de-scaling capacity when treating hypersaline feed.

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.

Raman multivariate curve resolution (Raman-MCR) is applied to examine how the hydration shell around poly(N,N-diethylacrylamide) (PDEAM) changes upon heating, in comparison with poly(N-isopropylacrylamide) (PNIPAM), both of which undergo a clouding transition near room temperature. We report that PDEAM possesses a less-ordered and smaller hydration shell than PNIPAM. Furthermore, the PDEAM hydration-shell structure is insensitive to the occurrence of clouding, indicating the coil-globule transition and aggregation of multiple chains can be achieved without the hydration-shell structural transformation.

The advanced oxidation process of the photo-Fenton reaction can produce hydroxyl radicals with extremely strong oxidizing properties for the efficient and green degradation of various chemical and microbial pollutants. Herein, we report an approach to fabricating heterogeneous Fenton catalysts of

Electrospun nanofibrous membranes (ENM) possess many advantages over commonly utilized water purification systems. They provide high porosity with interconnected pores and a high surface to volume ratio, facilitating particle adsorption. Affinity separation moves into a promising future for application, for example, nanoparticle adsorption with excellent filtration efficiency, because of its highly specific adsorption mechanism. However, not all effects on filtration performance are entirely understood. In this paper, we investigate significant filtration parameters, such as pore size, mechanical stability, and hydrophilicity, and determine a sequence of importance for an optimal pressure drop. Copolymers with various hydrophilic functional groups such as acid, amide, pyridine, and quaternary amine were utilized. Effects on the pressure drop or nanoparticle filtration efficiency can then easily be attributed to the corresponding functional group. UV-light was used to induce cross-linking in the membranes, which subsequently surpassed the mechanical stability of commonly used hydrophobic membranes. A maximum tensile-stress of up to 11.6 MPa was obtained, whereby an optimization of at least 22% was achieved. Moreover, these cross-links reduce fiber swelling by a maximum of 26%. The membrane potential depends on the different functional groups and their incorporation number from 10 to 50 mol %. Successful gold nanoparticle (AuNP) filtration in flow mode was demonstrated and highlighted the outstanding membrane properties and selectivity. The Nplus membrane achieved 100% filtration efficiency over a duration of 6 min, surpassing the Pyr membrane's performance. This was attributed to the ionic interaction of the Nplus membrane, in contrast with the physical adsorption of the Pyr membrane.

Phacoemulsification with implantation of intraocular lens (IOLs) has been widely applied as a standard treatment for cataract, which is the leading cause of vision impairment. However, it still remains a critical challenge to prevent posterior capsule opacification (PCO) in terms of postoperative visual quality. Herein, we report IOLs with mussel-inspired coatings for inhibiting lens epithelial cells and then preventing PCO through photothermal conversion effect. The mussel-inspired coatings are deposited on the nonoptical surface areas of IOLs, endowing the modified IOLs with efficient photothermal conversion property. The temperature can be facilely raised to 50-60 °C for the photothermal IOLs (PT-IOLs) by near-infrared (NIR) laser irradiation at a safe intensity of 0.3 W/cm

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.

Postoperative endophthalmitis (POE) has been the most threatening complication after cataract surgery, which perhaps can be solved by the antibiotic-loaded intraocular lens (IOL). However, most drug-loaded IOLs demonstrate insufficient drug quantity, short release time, increased implantation-related difficulties or other noticeable drawbacks. To prevent POE and to address these deficiencies, a drug-loaded copolymer IOL, prepared from poly (urethane acrylate) prepolymer, isobornyl methacrylate (IBOMA), N-vinyl-2-pyrrolidone (NVP), Irgacure 819, RUVA-93, and gatifloxacin (GAT), was rapidly fabricated via photocuring and by using a 3D-printed mold. This composite displayed an outstanding and controllable GAT release behavior

The tympanic membrane plays an important role in the human hearing system, which is easily perforated under unfavorable conditions, leading to loss of hearing and otitis media. Many autologous materials and artificial materials have been used to repair a perforated tympanic membrane, but these materials sometimes can cause severe hearing loss because of their adhesion to the ossicle during the healing process and the postoperative process. Herein, we report Janus membranes with asymmetric cellular adhesion behaviors for regenerating the eardrum. These Janus membranes are constructed by co-depositing a tannic acid (TA)/3-aminopropyltriethoxysilane (APTES) coating on one surface of the polypropylene microfiltration membrane. Cellular experiments indicate that the Janus membranes have good biocompatibility and asymmetric cellular adhesion properties. The repair of the tympanic membrane perforation experiment and laser Doppler vibrometer (LDV) measurements prove that the hydrophilic surface of Janus membranes repairs perforated eardrums, and meanwhile the hydrophobic surface can avoid adhering to the inner ear tissue for reducing hearing loss. The Janus membranes have good prospects in the treatment of tympanic membrane perforation.

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.

Elaborate design of metal-organic frameworks (MOFs) composites with enhanced properties is of fundamental interest and practical importance in the fields of catalysis. Typical strategies are usually focused on how to increase MOFs contents while lacking architecture design for performance improvements. Herein, we first report MOFs composites with Janus structures to boost catalytic performance by Le Châtelier's principle when using wood aerogel as a versatile platform. Janus structures mean that one part of the composite is still wood aerogel while the other part is decorated with MOFs. The underoil hydrophilicity of the wood aerogels endows the Janus composites with dehydration capacity for promoting the equilibrium movement so as to boost the catalytic performance. The catalytic performance of Janus composites for the Knoevenagel reaction increases more than 40% compared with those symmetric composites. Moreover, both the final conversion and the reaction rate are much better for the Janus composites than other state-of-the-art heterogeneous ZIF-8-based catalysts. Our design is general and paves the way to exploit composites with special architecture.

Raman multivariate curve resolution (Raman-MCR) is applied to examine how the hydration shell around poly(

Mussel-inspired chemistry has become an ideal platform to engineer a myriad of functional materials, but fully understanding the underlying adhesion mechanism is still missing. Particularly, one of the most pivotal questions is whether catechol still plays a dominant role in molecular-scale adhesion like that in mussel adhesive proteins. Herein, for the first time, we reveal an unexplored adhesion mechanism of mussel-inspired chemistry that is strongly dictated by 5,6-dihydroxyindole (DHI) moieties, amending the conventional viewpoint of catechol-dominated adhesion. We demonstrate that polydopamine (PDA) delivers an unprecedented adhesion of 71.62 mN m