Porous ionic polymers (PiPs) are newly emerging organic porous polymers. In sharp contrast to charge-neutral porous polymers, ionic moieties are either incorporated into the polymer backbone, or are ...covalently attached to a polymeric framework. Therefore, their physicochemical properties, functional groups, and active sites can be easily modified through screening of building blocks and ionic tectons. Meanwhile, their surface area, pore size, and pore volume can also be tuned by counterions exchange. Intrinsic functionalization further broadens the application range of the PiPs. This review will describe the recent advancements with regard to PiPs, and their development in the area of gas adsorption, catalysis, antibacterial applications and water purification.
Metal nanowires (NWs) have become the most promising candidates for the next generation of flexible transparent conductive electrodes (FTCEs), with high transmittance and low sheet resistance. In ...this work, ultralong silver NWs (Ag NWs), ∼220 μm (even larger than 400 μm) in length and ∼55 nm in diameter (aspect ratio: ∼4000), were synthesized via a one-pot polyol process using high molecular weight poly(vinylpyrrolidone) (M w = 1 300 000) and an appropriate concentration of FeCl3 (12.5 μM) through hydrothermal reaction. The prepared Ag NWs were purified by a filter cloth (pore size: about 30 × 50 μm2) to remove the Ag nanoparticles and short-length Ag NWs. The FTCE based on the ultralong Ag NWs without any post-treatments exhibits low sheet resistance of 155.0 Ω sq–1 and transmittance of 97.70% at 550 nm. The outstanding performance of FTECs demonstrated that the ultralong Ag NWs are ideal materials for applications in flexible transparent optical devices.
Pyrrolidinium-type small molecule ionic liquids (ILs), poly(ionic liquid) (PIL) homopolymers, and their corresponding PIL membranes were synthesized and used for antibacterial applications. The ...influences of substitutions at the N position of pyrrolidinium cation on the antimicrobial activities against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were studied by minimum inhibitory concentration (MIC). The antibacterial efficiency of both the small molecule ILs and PIL homopolymers increased with the increase of the alkyl chain length of substitutions. Furthermore, PIL homopolymers show relatively lower MIC values, indicating better antimicrobial activities than those of the corresponding small molecule ILs. However, the antibacterial properties of the PIL membranes are contrary to corresponding ILs and PIL homopolymers, which reduce with the increase of alkyl chain length. Furthermore, the resultant PIL membranes show excellent hemocompatibility and low cytotoxicity toward human cells, demonstrating clinical feasibility in topical applications.
Alkaline alcohols (methanol, ethanol, propanol, and ethylene glycol) have been applied as fuels for alkaline anion exchange membrane fuel cells. However, the effects of alkaline media on the ...stability of anion exchange membranes (AEMs) are still elusive. Here, a series of organic cations including quaternary ammonium, imidazolium, benzimidazolium, pyridinium, phosphonium, pyrrolidinium cations, and their corresponding cationic polymers are synthesized and systematically investigated with respect to their chemical stability in various alkaline media (water, methanol, ethanol, and dimethyl sulfoxide) by quantitative 1H nuclear magnetic resonance spectroscopy and density functional theory calculations. In the case of protic solvents (water, methanol, and ethanol), the lower dielectric constant of the alkaline media, the lower is the lowest unoccupied molecular orbital (LUMO) energy of the organic cation, which leads to the lower alkaline stability of cations. However, the hydrogen bonds between the anions and protic solvents weaken the effects of low dielectric constant of the alkaline media. The aprotic solvent accelerated the SN2 degradation reaction of “naked” organic cations. The results of this study suggest that both the chemical structure of organic cations and alkaline media (fuels) applied affect the alkaline stability of AEMs.
The alkaline stability of organic cations and cationic polymers in various alkaline media (water, methanol, ethanol and DMSO) is characterized using quantitative 1H NMR spectra and density functional theory calculations.
Gels that are freeze-resistant and heat-resistant and have high ultimate tensile strength are desirable in practical applications owing to their potential in designing flexible energy storage ...devices, actuators, and sensors. Here, a simple method for fabricating ionic liquid (IL)-based click-ionogels using thiol-ene click chemistry under mild condition is reported. These click-ionogels continue to exhibit excellent mechanical properties and resilience after 10,000 fatigue cycles. Moreover, due to several unique properties of ILs, these click-ionogels exhibit high ionic conductivity, transparency, and nonflammability performance over a wide temperature range (-75° to 340°C). Click-ionogel-based triboelectric nanogenerators exhibit excellent mechanical, freeze-thaw, and heat stability. These promising features of click-ionogels will promote innovative applications in flexible and safe device design.
As an inflammatory skin disease of pilosebaceous follicles, Propionibacterium acnes (P. acnes) can aggravate local inflammatory responses and forms acne lesions. However, due to the skin barrier, ...various transdermal measures other than antibiotic creams are necessary. Microneedle (MN) patches are emerging platforms for the transdermal delivery of various therapeutics since it can effectively create transport pathways in the epidermis. Herein, we develop an active pharmaceutical ingredient poly(ionic liquid) (API PIL)-based MN patches containing salicylic acid (SA). The PIL-based MNs are simply prepared through photo-crosslinking of an imidazolium-type ionic liquid (IL) monomer in MN micro-molds, and following by anion exchange with salicylic acid anions (SA
). The fabricated SA-loaded PIL-MNs exhibited therapeutic efficiency in the topical treatment of P. acnes infection in vitro and in vivo. These active pharmaceutical ingredient PIL-based MNs can improve acne treatment, demonstrating potential applications for skin diseases. STATEMENT OF SIGNIFICANCE: Microneedle (MN) patches can be used as platforms for transdermal delivery of various therapeutics to treat bacterial infection. Here, a facile strategy was developed to synthesize active pharmaceutical ingredient poly(ionic liquid)-based microneedle patches by anion-exchange with salicylic acid anion (SA
). The fabricated SA-loaded PIL-MNs are active on not only anti-bacteria but also anti-inflammation in P. acnes treated mice, and may have potential applications for skin acne infection.
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.
A robust and flexible polymer velcro was synthesized
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surface modification of poly(ionic liquid) (PIL) membranes with ferrocene (Fc) and β-cyclodextrin (β-CD) moieties, which act as the hooks and ...loops, respectively. Through molecular recognition between the β-CD and Fc moieties, the prepared PIL-β-CD and PIL-Fc membranes adhered with each other under mechanical compression, without the use of any curing agents. This polymer velcro exhibits strong adhesion in air and in aqueous solutions (including acidic and basic water, and artificial seawater), and could be unfastened and fastened by mechanical and chemical means. Due to the intrinsic ionic conductivity of the PIL membranes, our polymer velcro possesses an unprecedented feature, that the adhesion reversibility can be electrochemically controlled by the applied potential.
Polymer velcro with voltage-switchable adhesion was synthesized
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surface modification of poly(ionic liquid) membranes with ferrocene (Fc) and β-cyclodextrin (β-CD) moieties.
Poly(ionic liquid) (PIL) gels with CO2 stimulus responsiveness have been synthesized through the copolymerization of an imidazolium‐type ionic liquid monomer with 2‐(dimethyl amino) ethyl ...methacrylate. Upon bubbling with CO2 gas, the prepared PIL solution is converted to a transparent and stable gel, which can be turned back to the initial solution state after N2 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.
Poly(ionic liquid) (PIL) gels with CO2 stimuli responsiveness are synthesized through the copolymerization of an imidazolium‐type ionic liquid monomer with 2‐(dimethyl amino) ethyl methacrylate. Upon bubbling with CO2 gas, the prepared PIL solution is converted to a transparent and stable gel, which can be turned back to the initial solution state after N2 bubbling.
Electroactive supramolecular gels with multistimuli responsiveness were fabricated through host–guest interactions between a host polymer containing β-cyclodextrin (CD) and an ionic liquid (IL) type ...asymmetric gemini guest, which contains both ferrocene (Fc) and bis(trifluoromethyl-sulfonyl)imide (TFSI–) as the respective α- and ω-guest groups. Owing to the multiple stimuli-responsiveness of the host–guest interactions, reversible sol–gel phase transition could be triggered by various stimuli, including temperature, electrochemical/chemical redox and anion-exchange reactions. Due to the intrinsically conductive properties of the IL gemini guest, the sol–gel transition behavior could be electrochemically controlled by the applied voltage, without using additional supporting electrolyte.
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