Amphiphilically Modified Porous Polymeric Nanosandwich-Based Membranes for Rapid and Efficient Water Treatment.

Low removal efficiency, long treatment time, and high energy consumption hinder advanced and eco-friendly use of traditional adsorbents and separation membranes. Here, a class of amphiphilically modified 2D porous polymeric nanosandwich is designed and is subsequently assembled into adsorptive membranes. The 2D nanosandwich is gifted with high porosity and excellent pore accessibility, demonstrating rapid adsorption kinetics. The as-assembled membrane integrates unimpeded interlayer channels and well-developed, amphiphilic, and highly accessible intralayer nanopores, leading to ultrafast water permeation (1.2 × 104  L m-2  h-1  bar-1 ), high removal efficiency, and easy regeneration. The family of the membrane can be expanded by changing amphiphilic functional groups, further providing treatment of a wide-spectrum of pollutants, including aromatic compounds, pesticide, and pharmaceuticals. It is believed that the novel amphiphilically modified adsorptive membrane offers a distinct water treatment strategy with ultrahigh water permeation and efficient pollutants removal performances, and provides a multiple-in-one solution to the detection and elimination of pollutants.

Facile and Universal Defect Engineering Toward Highly Stable Carbon-Based Polymer Brushes with High Grafting Density.

Carbon-based polymer brushes (CBPBs) are an important class of functional polymer materials, which synergistically combine the advantageous properties of both carbons and polymers. However, the conventional fabrication procedures of CBPBs involve tedious multistep modification, including preoxidation of carbon substrates, introduction of initiating groups, and subsequent graft polymerization. In this study, a simple yet versatile defect-engineering strategy is proposed for the efficient synthesis of high-grafting-density CBPBs with highly stable CC linkages via free radical polymerization. This strategy involves the introduction and removal of nitrogen heteroatoms in the carbon skeletons via a simple temperature-Fmed heat treatment, leading to the formation of numerous carbon defects (e.g., pentagons, heptagons, and octagons) with reactive C=C bonds in the carbon substrates. The as-proposed methodology enables the facile fabrication of CBPBs with various carbon substrates and polymers. More importantly, the highly grafted polymer chains in the resulting CBPBs are tethered with the carbon skeletons by robust CC bonds, which can endure strong acid and alkali environments. These interesting findings will shed new light on the well-orchestrated design of CBPBs and broaden their applications in various areas with fascinating performances.

Emerging porous organic polymers for biomedical applications.

Porous organic polymers (POPs) have emerged as a new class of multifunctional porous materials and received tremendous research attention from both academia and industry. Most POPs are constructed from versatile organic small molecules with diverse linkages through strong covalent bonds. Owing to their high surface area and porosity, low density, high stability, tunable pores and skeletons, and ease of functionalization, POPs have been extensively studied for gas storage and separation, heterogeneous catalysis, biomedicine, sensing, optoelectronics, energy storage and conversion, etc. Particularly, POPs are excellent platforms with exciting opportunities for biomedical applications. Consequently, considerable efforts have been devoted to preparing POPs with an emphasis on their biomedical applications. In this review, first, we briefly describe the different subclasses of POPs and their synthetic strategies and functionalization approaches. Then, we highlight the state-of-the-art progress in POPs for a variety of biomedical applications such as drug delivery, biomacromolecule immobilization, photodynamic and photothermal therapy, biosensing, bioimaging, antibacterial, bioseparation, etc. Finally, we provide our thoughts on the fundamental challenges and future directions of this emerging field.

Self-Supporting Electrocatalyst Film Based on Self-Assembly of Heterogeneous Bottlebrush and Polyoxometalate for Efficient Hydrogen Evolution Reaction.

Developing efficient electrocatalysts to promote the hydrogen evolution reaction (HER) is essential for a green and sustainable future energy supply. For practical applications, it is a challenge to achieve the self-assembly of electrocatalyst from microscopic to macroscopic scales. Herein, a facile strategy is proposed to fabricate a self-supporting electrocatalyst film (CNT-g-PSSCo/PW12 ) for HER by electrostatic interaction-induced self-assembly of cobalt polystyrene sulfonate-grafted carbon nanotube heterogeneous bottlebrush (CNT-g-PSSCo) and polyoxometalate (PW12 ). Co2+ ions of CNT-g-PSSCo can function as junctions for interconnecting neighboring bottlebrushes to form the 3D nanonetwork structure and enable electrostatic capture of negatively charged PW12 nanodots. Moreover, CNT backbones can provide highly conductive pathways to CNT-g-PSSCo/PW12 . Such a self-assembled CNT-g-PSSCo/PW12 displays a low overpotential of 31 mV at a current density of 10 mA cm-2 and a small Tafel slope of 25 mV dec-1 , showing high efficiency toward HER. Furthermore, CNT-g-PSSCo/PW12 with a stable self-supporting film morphology exhibits long-term electrocatalytic stability over 1000 CV cycles without noticeable overpotential change in acidic media. The findings may provide a new avenue for constructing self-assembled functional nanonetwork materials with well-orchestrated structural hierarchy for many applications in energy, environment, catalysis, medicine, and others.

Water-Dispersible, Responsive, and Carbonizable Hairy Microporous Polymeric Nanospheres.

Multifunctionalization of microporous polymers is highly desirable but remains a significant challenge, considering that the current microporous polymers are generally hydrophobic and nonresponsive to different environmental stimuli and difficult to be carbonized without damage of their well-defined nanomorphology. Herein, we demonstrate a facile and versatile method to fabricate water-dispersible, pH/temperature responsive and readily carbonizable hairy microporous polymeric nanospheres based on combination of the hyper-cross-linking chemistry with the surface-initiated atom transfer radical polymerization (SI-ATRP). The hyper-cross-linking creates a highly microporous core, whereas the SI-ATRP provides diverse functionalities by surface grafting of hairy functional blocks. The as-prepared materials present multifunctional properties, including sensitive response to pH/temperature, high adsorption capacity toward adsorbates from aqueous solution, and valuable transformation into well-defined microporous carbon nanospheres because of hybrid of carbonizable core and thermo-decomposable protection shell. We hope this strategy could promote the development of both functional microporous polymers and advanced hairy nanoparticles for multipurpose applications.

Radical covalent organic frameworks: a general strategy to immobilize open-accessible polyradicals for high-performance capacitive energy storage.

Ordered π-columns and open nanochannels found in covalent organic frameworks (COFs) could render them able to store electric energy. However, the synthetic difficulty in achieving redox-active skeletons has thus far restricted their potential for energy storage. A general strategy is presented for converting a conventional COF into an outstanding platform for energy storage through post-synthetic functionalization with organic radicals. The radical frameworks with openly accessible polyradicals immobilized on the pore walls undergo rapid and reversible redox reactions, leading to capacitive energy storage with high capacitance, high-rate kinetics, and robust cycle stability. The results suggest that channel-wall functional engineering with redox-active species will be a facile and versatile strategy to explore COFs for energy storage.

Synthesis of well-defined microporous carbons by molecular-scale templating with polyhedral oligomeric silsesquioxane moieties.

Formation of a uniform interface between the carbon precursor and the selected template is critical for preparing high-quality nanoporous carbons. It can be accomplished by various templating procedures but still remains a challenge, especially for microporous carbons. A new strategy to fabricate well-defined microporous carbon nanosphere (MCNS) materials via molecular-scale interfacial engineering using an organic/inorganic hybrid molecule as the building block was designed. A commercially available octaphenyl polyhedral oligomeric silsesquioxane was selected as such a building block and transformed into the MCNS products via cross-linking of organic components, followed by carbonization, and subsequent removal of monodispersed silica domains, surrounded by molecular-scale carbon/silica interfaces. The obtained MCNS materials exhibit very large surface area (e.g., 2264 m(2)/g) and fast and selective sorption, and thus demonstrate excellent adsorption and supercapacitance properties. These findings could provide a new benchmark for preparing well-defined nanoporous carbons for various applications.

Ammonia-assisted semicarbonization: a simple method to introduce micropores without damaging a 3D mesoporous carbon nanonetwork structure.

A simple and effective way to introduce micropores into skeleton of carbon aerogel (CA) without damaging its unique 3D mesoporous nanonetwork has been successfully developed by NH3-assisted semicarbonization. During the NH3-assisted semicarbonization process, nitrogen functional groups with high thermo-decomposable ability like pyrrolic/pyridine and pyridinic can be introduced into the semicarbonized aerogel framework by substituting oxygen functional groups with low thermo-decomposable ability like C═O quinone-type groups and then escape from the resultant CA framework during the subsequent carbonization, thus forming abundant micropores inside carbon framework under the circumstance of keeping wonderful stability of mesoporous nanonetwork structure. Compared with the traditional CA without NH3 assistance during semicarbonization, the as-prepared novel CA represents a much higher surface area (1100 vs 620 m(2) g(-1)) and a compatible mesopore structure. Meanwhile, such a NH3 treatment confers many useful nitrogen functional groups on the nanonetwork framework. The novel CA is then used as electrode material of supercapacitors and shows a much higher capacitance and comparable high capacitance retention as compared with the traditional CA.

Templated synthesis of nitrogen-enriched nanoporous carbon materials from porogenic organic precursors prepared by ATRP.

A facile templated synthesis of functional nanocarbon materials with well-defined spherical mesopores is developed using all-organic porogenic precursors comprised of hairy nanoparticles with nitrogen-rich polyacrylonitrile shells grafted from sacrificial cross-linked poly(methyl methacrylate) cores (xPMMA-g-PAN). Such shape-persistent all-organic nanostructured precursors, prepared using atom transfer radical polymerization (ATRP), assure robust formation of template nanostructures with continuous PAN precursor matrix over wide range of compositions, and allow for removal of the sacrificial template through simple thermal decomposition. Carbon materials prepared using this method combine nitrogen enrichment with hierarchical nanostructure comprised of microporous carbon matrix interspersed with mesopores originating from sacrificial xPMMA cores, and thus perform well as CO2 adsorbents and as supercapacitor electrodes.

Synergistic Drug-Loaded Shear-Thinning Star Polymer Hydrogel Facilitates Gastrointestinal Lesion Resection and Promotes Wound Healing.

Easy injection, long-lasting barrier, and drug loading are the critical properties of submucosal injection materials for endoscopic surgery. However, conventional injectable polymers face challenges in simultaneously attaining these properties due to the inherent conflict between injectability and in situ stability. Here, a multi-arm star polymer hydrogel (denoted as ßCP hydrogel) with long-lasting submucosal barrier (exceeding 120 min), rapid hemostasis, and sustained antibacterial properties is successfully developed by grafting poly(oligo(ethylene glycol) methyl ether methacrylate) (PEGMA) side-chains from ß-CD via atom transfer radical polymerization (ATRP). During the onset of shearing, ßCP hydrogel experiences the unwinding of polymer side-chains between neighboring star polymers, which facilitates the process of endoscopic injectability. After submucosal injection, ßCP hydrogel undergoes the winding of polymer side-chains, thereby establishing a long-lasting barrier cushion. Meanwhile, owing to its distinctive structures with a hydrophobic inner cavity and an outer layer of hydrophilic polymer side-chains, ßCP hydrogel enables simultaneous loading and on-demand release of diverse categories of drugs. This unique performance can adapt to the diverse demands during different stages of wound healing in a porcine endoscopic surgery model. These results indicate an appealing prospect for new application of star polymers as a good submucosal injection material in endoscopic treatments.

Super-Structured Wet-Adhesive Hydrogel with Ultralow Swelling, Ultrahigh Burst Pressure Tolerance, and Anti-Postoperative Adhesion Properties for Tissue Adhesion.

Wet-adhesive hydrogels have been developed as an attractive strategy for tissue repair. However, achieving simultaneously low swelling and high burst pressure tolerance of wet-adhesive hydrogels is crucial for in vivo application which remains challenges. Herein, a novel super-structured porous hydrogel (denoted as PVA/PAAc-N+ ) is designed via facile moisture-induced phase separation-solvent exchange process for obtaining porous polyvinyl alcohol (PVA) hydrogel as dissipative layer and in situ photocuring technology for entangling quaternary ammonium-functionalized poly(acrylic acid)-based wet-adhesive layer (PAAc-N+ ) with the porous surface of PVA layer. Benefitting from the ionic crosslinking between quaternary ammonium ions and carboxylate ions in PAAc-N+ wet-adhesive layer as well as the high crystallinity induced by abundant hydrogen bonds of PVA layer, the hydrogel has unique ultralow swelling property (0.29) without sacrificing adhesion strength (63.1 kPa). The porous structure of PVA facilitates the mechanical interlock at the interface between PAAc-N+ wet-adhesive layer and tough PVA dissipative layer, leading to the ultrahigh burst pressure tolerance up to 493 mm Hg and effective repair for porcine heart rupture; the PVA layer surface of PVA/PAAc-N+ hydrogel can prevent postoperative adhesion. By integrating ultralow swelling, ultrahigh burst pressure tolerance, and anti-postoperative adhesion properties, PVA/PAAc-N+ hydrogel shows an appealing application prospect for tissue repair.

Hydrogel Encapsulating Wormwood Essential Oil with Broad-spectrum Antibacterial and Immunomodulatory Properties for Infected Diabetic Wound Healing.

The integration of hydrogels with bio-friendly functional components through simple and efficient strategies to construct wound dressings with broad-spectrum antibacterial and immunomodulatory properties to promote the healing of infected diabetic wounds is highly desirable but remains a major challenge. Here, wormwood essential oil (WEO) is effectively encapsulated in the hydrogel via an O/W-Pickering emulsion during the polymerization of methacrylic anhydride gelatin (GelMA), acrylamide (AM), and acrylic acid N-hydroxysuccinimide ester (AAc-NHS) to form a multifunctional hydrogel dressing (HD-WEO). Compared with conventional emulsions, Pickering emulsions not only improve the encapsulation stability of the WEO, but also enhance the tensile and swelling properties of hydrogel. The synergistic interaction of WEO's diverse bioactive components provides a broad-spectrum antibacterial activity against S. aureus, E. coli, and MRSA. In addition, the HD-WEO can induce the polarization of macrophages from M1 to M2 phenotype. With these advantages, the broad-spectrum antibacterial and immunomodulatory HD-WEO effectively promotes the collagen deposition and neovascularization, thereby accelerating the healing of MRSA-infected diabetic wounds.

Double-Layer Asymmetric Porous Mesh with Dynamic Mechanical Support Properties Enables Efficient Single-Stage Repair of Contaminated Abdominal Wall Defect.

Contamination tolerance and long-term mechanical support are the two critical properties of meshes for contaminated abdominal wall defect repair. However, biological meshes with excellent pollution tolerance fail to provide bio-adaptive long-term mechanical support due to their rapid degradation. Here, a novel double-layer asymmetric porous mesh (SIS/PVA-EXO) is designed by simple and efficient in situ freeze-thaw of sticky polyvinyl alcohol (PVA) solution on the loosely porous surface of small intestinal submucosal decellularized matrix (SIS), which can successfully repair the contaminated abdominal wall defect with bio-adaptive dynamic mechanical support through only single-stage surgery. The exosome-loaded degradable loosely porous SIS layer accelerates the tissue healing; meanwhile, the exosome-loaded densely porous PVA layer can maintain long-term mechanical support without any abdominal adhesion. In addition, the tensile strength and strain at break of SIS/PVA-EXO mesh change gradually from 0.37 MPa and 210% to 0.10 MPa and 385% with the degradation of SIS layer. This unique performance can dynamically adapt to the variable mechanical demands during different periods of contaminated abdominal wall reconstruction. As a result, this SIS/PVA-EXO mesh shows an attractive prospect in the treatment of contaminated abdominal wall defect without recurrence by integrating local immune regulation, tissue remodeling, and dynamic mechanical supporting.

One-Pot Construction of Articular Cartilage-Like Hydrogel Coating for Durable Aqueous Lubrication.

Articular cartilage has an appropriate multilayer structure and superior tribological properties and provides a structural paradigm for design of lubricating materials. However, mimicking articular cartilage traits on prosthetic materials with durable lubrication remains a huge challenge. Herein, an ingenious three-in-one strategy is developed for constructing an articular cartilage-like bilayer hydrogel coating on the surface of ultra-high molecular weight polyethylene (BH-UPE), which makes full use of conceptions of interfacial interlinking, high-entanglement crosslinking, and interface-modulated polymerization. The hydrogel coating is tightly interlinked with UPE substrate through hydrogel-UPE interchain entanglement and bonding. The hydrogel chains are highly entangled with each other to form a dense tough layer with negligible hysteresis for load-bearing by reducing the amounts of crosslinker and hydrophilic initiator to p.p.m. levels. Meanwhile, the polymerization of monomers in the top surface region is suppressed via interface-modulated polymerization, thus introducing a porous surface for effective aqueous lubrication. As a result, BH-UPE exhibits an ultralow friction coefficient of 0.0048 during 10 000 cycles under a load of 0.9 MPa, demonstrating great potential as an advanced bearing material for disc prosthesis. This work may provide a new way to build stable bilayer coatings and have important implications for development of biological lubricating materials.

Topological Defect-Regulated Porous Carbon Anodes with Fast Interfacial and Bulk Kinetics for High-Rate and High-Energy-Density Potassium-Ion Batteries.

Carbonaceous materials are regarded as one of the most promising anodes for potassium-ion batteries (PIBs), but their rate capabilities are largely limited by the slow solid-state potassium diffusion kinetics inside anode and sluggish interfacial potassium ion transfer process. Herein, high-rate and high-capacity PIBs are demonstrated by facile topological defect-regulation of the microstructure of carbon anodes. The carbon lattice of the as-obtained porous carbon nanosheets (CNSs) with abundant topological defects (TDPCNSs) holds relatively high potassium adsorption energy yet low potassium migration barrier, thereby enabling efficient storage and diffusion of potassium inside graphitic layers. Moreover, the topological defects can induce preferential decomposition of anions, leading to the formation of high potassium ion conductive solid electrolyte interphase (SEI) film with decreased potassium ion de-solvation and transfer barrier. Additionally, the dominant sp2-hybridized carbon conjugated skeleton of TDPCNSs enables high electrical conductivity (39.4 S cm-1) and relatively low potassium storage potential. As a result, the as-constructed TDPCNSs anode demonstrates high potassium storage capacity (504 mA h g-1 at 0.1 A g-1), remarkable rate capability (118 mA h g-1 at 40 A g-1), as well as long-term cycling stability.

All-in-one porous membrane enables full protection in guided bone regeneration.

The sophisticated hierarchical structure that precisely combines contradictory mechanical and biological characteristics is ideal for biomaterials, but it is challenging to achieve. Herein, we engineer a spatiotemporally hierarchical guided bone regeneration (GBR) membrane by rational bilayer integration of densely porous N-halamine functionalized bacterial cellulose nanonetwork facing the gingiva and loosely porous chitosan-hydroxyapatite composite micronetwork facing the alveolar bone. Our GBR membrane asymmetrically combine stiffness and flexibility, ingrowth barrier and ingrowth guiding, as well as anti-bacteria and cell-activation. The dense layer has a mechanically matched space maintenance capacity toward gingiva, continuously blocks fibroblasts, and prevents bacterial invasion with multiple mechanisms including release-killing, contact-killing, anti-adhesion, and nanopore-blocking; the loose layer is ultra-soft to conformally cover bone surfaces and defect cavity edges, enables ingrowth of osteogenesis-associated cells, and creates a favorable osteogenic microenvironment. As a result, our all-in-one porous membrane possesses full protective abilities in GBR.

Rough Endoplasmic Reticulum Inspired Polystyrene-Brush-Based Superhigh Sulfur Content Cathodes Enable Lithium-Sulfur Cells with High Mass and Capacity Loading.

The development of highly sophisticated biomimetic models is significant yet remains challenging in the electrochemical energy storage field. Lithium-sulfur (Li-S) cells with high sulfur content and high-sulfur-loading cathodes are urgently required to meet the fast-growing demand for electronic devices. Nevertheless, such cathode materials generally suffer from large sulfur agglomeration, nonporous structure, and insufficient conductivity, leading to rapid capacity decay and low sulfur utilization. Herein, inspired by rough endoplasmic reticulum, a 2D polystyrene (PS)-brush-based (G-g-PS) superhigh-sulfur-content (96 wt%) composite(G-g-sPS@S) is fabricated via the vulcanization reaction. The vulcanized PS side-chains and their S8 composites on the nanosheet surface can efficiently provide sulfur species, and the intersheet interstitial pores can provide rapid mass-transfer channels for redox reactions of sulfur species. Furthermore, the highly sulfophilic vulcanized PS side-chains are able to effectively inhibit the shuttle effect of polysulfides and regulate their redox process. With these merits, the cells with G-g-sPS@S cathodes exhibit an ultralow decay rate of 0.02% per cycle over 400 cycles at 2 C and deliver a superior areal capacity of 12.6 mAh cm-2 even with a high sulfur loading of 10.5 mg cm-2 .

A Versatile Sulfur-Assisted Pyrolysis Strategy for High-Atom-Economy Upcycling of Waste Plastics into High-Value Carbon Materials.

With the overconsumption of disposable plastics, there is a considerable emphasis on the recycling of waste plastics to relieve the environmental, economic, and health-related consequences. Here, a sulfur-assisted pyrolysis strategy is demonstrated for versatile upcycling of plastics into high-value carbons with an ultrahigh carbon-atom recovery (up to 85%). During the pyrolysis process, the inexpensive elemental sulfur molecules are covalently bonded with polymer chains, and then thermally stable intermediates are produced via dehydrogenation and crosslinking, thereby inhibiting the decomposition of plastics into volatile small hydrocarbons. In this manner, the carbon products obtained from real-world waste plastics exhibit sulfur-rich skeletons with an enlarged interlayer distance, and demonstrate superior sodium storage performance. It is believed that the present results offer a new solution to alleviate plastic pollution and reduce the carbon footprint of plastic industry.

Band-Aid-Like Self-Fixed Barrier Membranes Enable Superior Bone Augmentation.

In guided bone regeneration surgery, a barrier membrane is usually used to inhibit soft tissue from interfering with osteogenesis. However, current barrier membranes usually fail to resist the impact of external forces on bone-augmented region, thus causing severe displacement of membranes and their underlying bone graft materials, eventually leading to unsatisfied bone augmentation. Herein, a new class of local double-layered adhesive barrier membranes (ABMs) is developed to successfully immobilize bone graft materials. The air-dried adhesive hydrogel layers with suction-adhesion properties enable ABMs to firmly adhere to the wet bone surface through a "stick-and-use" band-aid-like strategy and effectively prevent the displacement of membranes and the leakage of bone grafts in uncontained bone defect treatment. Furthermore, the strategy is versatile for preparing diverse adhesive barrier membranes and immobilizing different bone graft materials for various surgical regions. By establishing such a continuous barrier for the bone graft material, this strategy may open a novel avenue for designing the next-generation barrier membranes.

NADPH Selective Depletion Nanomedicine-Mediated Radio-Immunometabolism Regulation for Strengthening Anti-PDL1 Therapy against TNBC.

Anti-PD(L)1 immunotherapy recently arises as an effective treatment against triple-negative breast cancer (TNBC) but is only applicable to a small portion of TNBC patients due to the low PD-L1 expression and the immunosuppressive tumor microenvironment (TME). To address these challenges, a multifunctional "drug-like" copolymer that possesses the auto-changeable upper critical solution temperature and the capacity of scavenging reduced nicotinamide adenine dinucleotide phosphate (NADPH) inside tumor cells is synthesized and employed to develop a hypoxia-targeted and BMS202 (small molecule antagonist of PD-1/PD-L1 interactions)-loaded nanomedicine (BMS202@HZP NPs), combining the anti-PD-L1 therapy and the low-dose radiotherapy (LDRT) against TNBC. In addition to the controlled release of BMS202 in the hypoxic TNBC, BMS202@HZP NPs benefit the LDRT by upregulating the pentose phosphate pathway (PPP, the primary cellular source for NADPH) of TME whereas scavenging the NADPH inside tumor cells. As a result, the BMS202@HZP NPs-mediated LDRT upregulate the PD-L1 expression of tumor to promote anti-PD-L1 therapy response while reprogramming the immunometabolism of TME to alleviate its immunosuppression. This innovative nanomedicine-mediated radio-immunometabolism regulation provides a promising strategy to reinforce the anti-PD-L1 therapy against TNBC.