Poly(ionic liquid) (PIL) gels with CO 2 stimulus responsiveness have been synthesized through the copolymerization of an imidazolium‐type ionic liquid monomer with 2‐(dimethyl amino) ethyl methacrylate. Upon bubbling with CO 2 gas, the prepared PIL solution is converted to a transparent and stable gel, which can be turned back to the initial solution state after N 2 bubbling. The reversible sol–gel phase transition behavior is proved by the reversible values of viscosity and ionic conductivity. The possible mechanism for such a reversible sol–gel phase transition is demonstrated by NMR, conductivity, and rheological measurements. image
Antibiotic resistance is considered as one of the serious public health issues. Antibacterial photocatalytic therapy, a clinically proven antibacterial therapy, is gaining increasing attention in recent years owing to its high efficacy. Here, an acridine-based covalent organic framework (COF) photosensitizer, named TPDA, with multiple active sites is synthesized via Schiff base condensation between 2,4,6-triformylphloroglucinol (TFP) and 3,6-diaminoacridine (DAA). Owing to the increased conjugation effect of the COF skeleton and outstanding light harvesting ability of DAA, TPDA exhibits a narrow optical band gap (1.6 eV), enhancing light energy transformation and conferring a wide optical absorption spectrum (intensity arbitrary unit > 0.8) ranging from the UV to near-infrared region. Moreover, TPDA shows high antibacterial activities against both gram-negative and gram-positive bacteria within a short time (10 min) of light irradiation and is found to efficiently protect fish from skin infections. Molecular dynamics simulation data show that the introduction of DAA and TFP facilitates the interaction between TPDA and bacteria and is conducive to reactive oxygen species migration, which further improves the antimicrobial performance. These findings indicate the potential of TPDA as a novel photosensitive material for photodynamic therapy.
Waterborne polyurethane (WPU) coatings have gained numerous attentions and popularity due to their outstanding structural tunability and environmental friendliness, but their applications are often limited due to their susceptibility to harbor bacteria and poor water resistance. Herein, a group of water-resistant antibacterial WPU coatings were developed by simultaneously incorporating imidazolium cations and siloxane groups into the WPU backbone. Utilizing imidazolium cations, the resulting WPU films and coatings demonstrated exceptional antibacterial efficacy against Escherichia coli and Staphylococcus aureus, with rates exceeding 99.99%. The incorporated siloxane groups are prone to migrate to the surface of the coatings/films due to their low surface free energy, thus significantly promoting the antifouling properties and hydrophobicity of the resulting WPU films/coatings.
Copper nanowires (Cu NWs) have become a promising material for flexible transparent conductive electrodes (FTCEs) owing to their outstanding transparency and conductivity properties. In this work, ultralong Cu NWs with an average length over 250 μm and a diameter of around 50 nm (aspect ratio ∼5000) were synthesized in a water/polyhydric alcohol cosolvent. The effects of polyhydric alcohols (including ethanol, ethylene glycol, and glycerol) on the aspect ratio of Cu NWs were investigated. The diameter of Cu NWs decreased with the increased number of hydroxyl groups of polyhydric alcohols. In addition, the capping ligands (oleylamine and oleic acid) and glucose also exhibit important effects on the dispersity and morphology of Cu NWs. The ultralong Cu NW-based poly(dimethylsiloxane) (PDMS) FTCEs exhibit high performance with a low sheet resistance of 92.1 Ω sq-1 at a transmittance of 91.524%. Inspired by the stretchable ability of PDMS, wearable sensors were fabricated to detect the movement of the finger joint through the chronoamperometry method. The prepared sensors exhibit high sensitivity and a fast response time. The excellent performance of FTCEs and wearable sensors suggests that the ultralong Cu NWs have a bright future in the application of the next generation of flexible optoelectronic devices.
Poly(ionic liquid)s are ionic polymers containing ionic liquid anion and cation structures in polymer repeating units. Poly(ionic liquid)s possess the physical and chemical properties of small ionic liquid molecules (structural diversity, adjustable solubility, chemical/thermal stability, conductivity, etc .) and the mechanical properties and processability of polymers, which makes it possible to apply in conductive materials, intelligent response materials, biomedical materials and other fields. This article mainly reviews the synthesis methods of poly(ionic liquid)s and their potential applications as functional materials in the fields of energy devices, smart response devices and antibacterial materials.
Abstract The development of aqueous metal‐ion batteries has attracted great attention due to their relatively low cost and high safety levels. However, their practical applications are hindered by the ease at which their aqueous electrolytes freeze. Inspired by the antifreezing properties of salts and alcohol cryoprotective agents, a “two‐in‐one” cryoprotective agent, hydroxyl‐functionalized poly(ionic liquid) (PIL‐OH)‐based hydrogel electrolyte for aqueous lithium‐ion batteries (ALIBs) is developed. The synergy of both ionic hydration and hydrogen bond interactions between the PIL‐OH and water molecules impairs the hydrogen‐bond networks of water and depresses the freezing point of water below −80 °C. Benefiting from exceptional ultralow temperature tolerance, the prepared PIL‐OH hydrogel exhibits a highly enhanced low temperature adaptability and a high ionic conductivity of 0.08 mS cm −1 at −80 °C. The PIL‐OH hydrogel‐based flexible ALIBs exhibit high flexible durability and good cycling stability with 93% capacity retention over 200 cycles at −80 °C. The PIL‐OH hydrogel report herein opens up new opportunities for practical applications of wearable and flexible aqueous batteries at ultralow temperature environments, such as the North and South Poles.
Imidazolium (Im), quaternary ammonium (Qa), and 1,4-diazabicyclo[2.2.2]octane-1,4-diium (DABCO-diium) cation-based small molecule cationic compounds and their corresponding side-chain/main-chain cationic polymers were synthesized.
Pandemic and epidemic spread of antibiotic-resistant bacterial infections would result in a huge number of fatalities globally. To combat antibiotic-resistant pathogens, new antimicrobial strategies should be explored and developed to confront bacteria without acquiring or increasing drug-resistance. Here, oxygen saturated perfluorohexane (PFH)-loaded mesoporous carbon nanoparticles (CIL@ICG/PFH@O
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