Hydrogels have emerged as promising antimicrobial materials due to their unique three-dimensional structure, which provides sufficient capacity to accommodate various materials, including small ...molecules, polymers and particles. Coating substrates with antibacterial hydrogel layers has been recognized as an effective strategy to combat bacterial colonization. To prevent possible delamination of hydrogel coatings from substrates, it is crucial to attach hydrogel layers via stronger links, such as covalent bonds. To date, various surface chemical strategies have been developed to introduce hydrogel coatings on different substrates. In this review, we first give a brief introduction of the major strategies for designing antibacterial coatings. Then, we summarize the chemical methods used to fix the antibacterial hydrogel layer on the substrate, which include surface-initiated graft crosslinking polymerization, anchoring the hydrogel layer on the surface during crosslinking, and chemical crosslinking of layer-by-layer coating. The reaction mechanisms of each method and matched pretreatment strategies are systemically documented with the aim of introducing available protocols to researchers in related fields for designing hydrogel-coated antibacterial surfaces.
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•Hydrogel coating has advantages of multipoint anchoring, uniform coverage and high loading capacity.•Antibacterial function can be designed by bacteria-repellent, contact-killing and bactericide-releasing.•Antibacterial hydrogel coating can be introduced by surface-initiated graft polymerization.•Anchoring hydrogel coating by incorporating surface functional groups into network during crosslinking.•Antibacterial hydrogel layer can be fabricated by chemical crosslinking of layer-by-layer coating.
Chromium (Cr) poses serious consequences on human and animal health due to its potential carcinogenicity. The present study aims at preparing a novel biochar derived from Chenopodium quinoa crop ...residues (QBC), its activation with magnetite nanoparticles (QBC/MNPs) and strong acid HNO3 (QBC/Acid) to evaluate their batch and column scale potential to remove Cr (VI) from polluted water. The QBC, QBC/MNPs and QBC/Acid were characterized with SEM, FTIR, EDX, XRD as well as point of zero charge (PZC) to get an insight into their adsorption mechanism. The impact of different process parameters including dose of the adsorbent (1–4 g/L), contact time (0–180 min), initial concentration of Cr (25–200 mg/L) as well as solution pH (2–8) was evaluated on the Cr (VI) removal from contaminated water. The results revealed that QBC/MNPs proved more effective (73.35–93.62-%) for the Cr (VI) removal with 77.35 mg/g adsorption capacity as compared with QBC/Acid (55.85–79.8%) and QBC (48.85–75.28-%) when Cr concentration was changed from 200 to 25 mg/L. The isothermal experimental results follow the Freundlich adsorption model rather than Langmuir, Temkin and Dubinin-Radushkevich adsorption isotherm models. While kinetic adsorption results were well demonstrated by pseudo second order kinetic model. Column scale experiments conducted at steady state exhibited excellent retention of Cr (VI) by QBC, QBC/MNPs and QBC/Acid at 50 and 100 mg Cr/L. The results showed that this novel biochar (QBC) and its modified forms (QBC/Acid and QBC/MNPs) are applicable with excellent reusability and stability under acidic conditions for the practical treatment of Cr (VI) contaminated water.
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•A novel biochar and its composites (QBC/MNPs and QBC/Acid) were used for Cr(VI) removal.•Composites were characterized with FTIR, SEM, EDX, XRD and PZC.•Experimental data were modelled with equilibrium and kinetic models.•QBC/MNPs could effectively remove Cr(VI) with adsorption capacity of 77.35 mg/g.•Column scale removal showed excellent retention of Cr and reusability.
Biochar (QBC/MNPs) was applicable with excellent reusability and stability under acidic conditions for the practical treatment of Cr (VI) contaminated water.
Phosphonic acids act as robust surface modifiers on barium titanate (BT) nanoparticles (NPs) (see figure), affording homogeneous, high‐volume‐fraction composites of such NPs in polymeric hosts by ...simple solution processing. Pentafluorobenzyl phosphonic acid‐modified BT nanocomposite films in poly(vinylidenefluoride‐co‐hexafluoropropylene) show large relative permittivities and unusually high dielectric breakdown strengths.
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•The Zn foil is coated by carbon black to enlarge the electroactive surface area.•Nanofibrillated cellulose is used as an effective binder to adhere carbon black.•The modified anode ...can eliminate the dendritic growth and side reactions.•Excellent interface stability between the anode and electrolyte is achieved.•The Zn-MnO2 battery with modified anode shows significantly improved cyclability.
Aqueous zinc-ion batteries have received significant attention due to their low cost and high safety. However, the unsatisfactory cycling performances caused by the dendritic growth on the Zn anode limit their practical applications. Herein, we propose to modify the conventional Zn foil anode by using carbon black coating and nanofibrillated cellulose binder. The carbon black can form an electrically conductive network, thus greatly enlarging the electroactive surface area, while the nanofibrillated cellulose can act as an electrolyte reservoir to facilitate charge transports. Thanks to that, the modified anode can significantly eliminate the dendritic growth and side reactions, therefore ensuring excellent interface stability with the electrolyte even at a commercial-level areal capacity of 5 mAh g−1. With the modified anode, the Zn-MnO2 battery gives a high capacity retention of 87.4% after 1000 cycles, much higher than that with the unmodified Zn foil (42.6%). This study discloses a facile, scalable, and cost-effective strategy to achieve dendrite-free metal electrodes towards great cyclability.
In the present study, algicidal bacteria cultivated in an aqueous medium were utilized as a surface modification agent to develop an efficient adsorbent for the removal of Microcystis aeruginosa. The ...modification considerably enhanced M. aeruginosa cell removal efficiency. Moreover, the introduction of bio-compounds ensured specificity in the removal of M. aeruginosa. Additionally, the cyanotoxin release and acute toxicity tests demonstrated that the adsorption process using the developed adsorbent is environmentally safe. Furthermore, the practical feasibility of the adsorptive removal of M. aeruginosa was confirmed through cell removal tests performed using the developed adsorbent in a scaled-up reactor (50 L and 10 tons). In these tests, the effects of the adsorbent application type, water temperature, and initial cell concentration on the M. aeruginosa removal efficiency were evaluated. The results of this study provide novel insights into the valorization strategy of biological algicides repurposed as adsorbents, and provide practical operational data for effective M. aeruginosa removal in scaled-up conditions.
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•Bacterial bio-compound was utilized as surface modifier for cotton adsorbent.•M. aeruginosa adsorption rate of bio-compound modified adsorbents was increased.•Surface modification of bio-compound increased selectivity for M. aeruginosa control.•Operation factor in adsorption process using developed adsorbent was investigated.•Harmful algal blooms adsorption process using developed adsorbent was environmentally safe.
•Successful surface modification of CF with 2 anthraquinone analogues (AQ-1, AQ-2).•A 6.6× and 5× increase in capacitance for AQ-2 and AQ-1 respectively over control.•An increase of 78% and 44% in ...IFSS over control for AQ-1 and AQ-2 respectively.•Translation to in-situ modification, maintaining a 3x increase in capacitance.
Carbon fiber electrodes were prepared by grafting anthraquinone molecules via a scalable electrochemical approach which simultaneously increased interfacial and electrochemical capacitance properties. In this work, anthraquinone diazonium salts were synthesized and grafted onto carbon fiber tows at various concentrations. These modified fibers were subsequently evaluated mechanically and electrochemically to analyze their suitability in structural supercapacitors. Compared to control fibers, the grafted anthraquinone groups resulted in a 30% increase in interfacial shear strength (IFSS) and 6.6× increase in specific capacitance. Industry application was also a focus thus carbon fibers were also modified with in-situ generated diazonium salts to determine the applicability to an in-line industrial process. Specifically, potentiostatic functionalization of fibers with in-situ generated diazonium salts AQ-1 and AQ-2, showed 3× and 4.3× increase in specific capacitance, respectively, relative to unmodified carbon fiber (CF). We expect that implementing a scalable method to introduce a conductive and electrochemically active covalently bound surface chemistry layer onto carbon fiber exhibits a higher specific capacitance than carbon fiber grafted with most other small molecules reported in literature. This will open new avenues for manufacturing multifunctional and high-performance fibers with tailored properties for specific/targeted applications.
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•Fluid density functional theory can accurately simulate the structure of grafting polyelectrolyte solutions at interfaces.•The influence of chain length and density of the grafted polyelectrolyte on ...interface structure and capacitance was revealed.•The grafted polymer brush disrupts the alternating layer of anions and cations at the conventional interface.
The structure of the electrode/electrolyte interface directly determines electrochemical performance. One effective method for controlling this interface structure is by grafting polyelectrolyte onto the electrode surface, which can significantly alter the double layer structure and enhance electrochemical performance. This study focuses on the graft modification of polyelectrolytes at the electrochemical interface and investigates the impact of the length and density of the grafted polyelectrolyte chain on the structure and capacitance of the electrode/ionic liquid interface using fluid density functional theory (FDFT). The findings indicate that the grafted polymerbrush disrupts the alternating layer of anions and cations at the conventional interface and exerts an additional adsorption effect on counter ions, thereby reducing the density of freely movable co-ions. Consequently, this process increases the effective charge and capacitance of the interface. The results of this investigation contribute to a deeper comprehension of polyelectrolyte solutions at solid–liquid interfaces and guide the regulation of electrochemical interface properties.
Clean water is an integral part of industries, agricultural activities and human life, but water contamination by toxic dyes, heavy metals, and oil spills is increasingly serious in the world. ...Aerogels with unique properties such as highly porous and extremely low density, tunable surface modification, excellent reusability, and thermal stability can contribute to addressing these issues. Thanks to high purity, biocompatibility and biodegradability, bacterial cellulose can be an ideal precursor source to produce aerogels. Here, we review the modification, regeneration, and applications of bacterial cellulose-based aerogels for water treatment. The modification of bacterial cellulose-based aerogels undergoes coating of hydrophobic agents, carbonization, and incorporation with other materials, e.g., ZIF-67, graphene oxide, nanoparticles, polyaniline. We emphasized features of modified aerogels on porosity, hydrophobicity, density, surface chemistry, and regeneration. Although major limits are relevant to the use of toxic coating agents, difficulty in bacterial culture, and production cost, the bacterial cellulose aerogels can obtain high performance for water treatment, particularly, catastrophic oil spills.
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•Bacterial cellulose had high purity and biodegradability for aerogels production•Hydrophobic coating, carbonization and additive incorporation valorized aerogels•Bacterial cellulose aerogels possess ultrahigh porosity, ultralow density, high thermal stability•High effectiveness to oil separation and excellent regeneration were obtained
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•Cu cocatalyst can serve as the active site for C-C coupling.•SCN-induced surface dipole effect can enhance the carrier’s dynamic behavior and accelerate the multielectron ...transfer.•SCN- ions with nucleophilicity are conducive to CO hydrogenation and the multi-proton coupling process of C2+ products.•Cu species can effectively reduce the reaction energy of the key intermediate *CO-COH of ethylene.•SCN- ion modification of Cu/TiO2-SBO contributes to greatly promoting the adsorption capacity for CO2.
Titanium dioxide (TiO2) with defects is a promising semiconductor photocatalyst for photoreduction CO2, due to its unique electronic properties. However, defective TiO2 is difficult to achieve a high yield of CO2 photoreduction, especially the high-value-added C2+ hydrocarbons, due to the slow transfer of multielectron/proton and sluggish C-C coupling kinetics. Here, we combine the photoinduced deposition of copper (Cu) nanoparticle on defective titania (TiO2-SBO) with thiocyanate anion (SCN-, KSCN) surface modification via impregnation route to prepare a series of high performance photocatalysts (SCN-Cu/TiO2-SBO). It was found that the production rate and selectivity of C2H4 of CO2 over sample SCN-Cu/TiO2-SBO-3 as a representative are 4.7 μmol·g−1·h−1 and 40%, while the CO and CH4 yields rise by 2 times and 5 times as compared with those over bare TiO2-SBO. This is because the Cu cocatalyst can serve as the active site for C-C coupling (via intermediate *CO-COH) and the SCN-induced surface dipole effect can enhance the carrier’s dynamic behavior and accelerate the multielectron transfer, while the SCN- ions with nucleophilicity are conducive to CO2 adsorption as well as CO hydrogenation and the multi-proton coupling process of C2+ products. Furthermore, first principle calculations illustrate that the Cu species can effectively reduce the reaction energy of the key intermediate *CO-COH of ethylene, and SCN- ions benefit to the adsorption of CO2 molecules, and thereby being favor for the generation of ethylene.
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•A perovskite structure LSGM material was served as membrane support.•The Al2O3 coating on the porous support can improve the wettability.•The Al2O3 modified LSGM-based membrane ...achieves a high CO2 permeation flux.
A perovskite structure La0.8Sr0.2Ga0.8Mg0.2O3−δ (LSGM), is a promising support material for dual − phase membrane for high − temperature CO2 separation owing to its high oxygen ion conductivity. The microstructure plays an important role in CO2 separation performance of the membrane. The result shows that effective particle − to − particle contact is a crucial guarantee for improving CO2 permeability. The uniformly distributed small pores of the support can greatly reduce the leakage. The Al2O3 coating on the porous support can improve the wettability between LSGM and molten carbonate, simultaneously increasing CO2 permeation flux while reducing leakage. The Al2O3 coated LSGM − based dual − phase membrane achieves a CO2 permeation flux of 0.34 mL min−1 cm−2 at 750 °C, with no detectable leakage. Above 750 °C, a reaction occurs between LSGM and molten carbonate, leading to a decline in membrane performance. For LSGM − carbonate dual − phase membranes, it is recommended to operate at temperatures not exceeding 750 °C.
