Hybrid Gel Electrolytes Derived from Keggin-Type Polyoxometalates and Imidazolium-Based Ionic Liquid with Enhanced Electrochemical Stability and Fast Ionic Conductivity

New hybrid gel electrolytes, derived from synergetic self-assembling of inorganic polyoxometalates (POMs) and organic ionic liquid (IL) components, have been successfully prepared using Keggin-type heteropolyanions such as {PMo₁₁VO₄₀}^4– and {PW₁₁MoO₄₀}^3– and ionic liquid <i>N</i>-methyl imidazolium-1-(3-sulfonic group) propyl (MIMPS). Powder X-ray diffraction study reveals that these hybrid gels possess lamellar structure and exhibit characteristic thermo-tropic liquid-crystalline behavior. Ionic conductivity (σ) of ∼0.1 S cm^–1 under ambient conduction was observed at 93 °C for [MIMPS]₄PMo₁₁VO₄₀ (IL-PMo₁₁V) and [MIMPS]₃PW₁₁MoO₄₀ (IL-PW₁₁Mo) hybrid gels. The electrochemical stability window (ESW) of IL-PMo₁₁V and IL-PW₁₁Mo seem to be about 2 and 4 V, respectively, at room temperature. The POM-based IL gel electrolytes show super ionic conductivity and high ESW compared to other known IL-based electrolytes, including 1-dodecyl-3-methylimidazolium-bis­(pentafluoro-ethylsolfonyl)­imide (σ = 0.003 S cm^–1 at 94 °C, ESW = 3.5 V), 1-dodecylimidazolium-bis­(pentafluoro-ethylsolfonyl)­imide (σ = 0.002 S cm^–1 at 94 °C, ESW = 3 V), SiO₂/1-methy-3-propylpiperidinium/bis­(trifluoro methanesulphonyl)­imide (σ = 0.014 S cm^–1 at 85 °C, ESW = 1.5 V), and 1-ethyl-3-methylimidazolium tetracyanoborate/poly­(vinylidene fluride-<i>co</i>-hexafluoropropylene (σ = 0.027 S cm^–1 at 90 °C, ESW = 3.8 V)

Block Copolymer Micelles with a Dual-Stimuli-Responsive Core for Fast or Slow Degradation

We report the design and demonstration of a dual-stimuli-responsive block copolymer (BCP) micelle with increased complexity and control. We have synthesized and studied a new amphiphilic ABA-type triblock copolymer whose hydrophobic middle block contains two types of stimuli-sensitive functionalities regularly and repeatedly positioned in the main chain. Using a two-step click chemistry approach, disulfide and <i>o</i>-nitrobenzyle methyl ester groups are inserted into the main chain, which react to reducing agents and light, respectively. With the end blocks being poly­(ethylene oxide), micelles formed by this BCP possess a core that can be disintegrated either rapidly via photocleavage of <i>o</i>-nitrobenzyl methyl esters or slowly through cleavage of disulfide groups by a reducing agent in the micellar solution. This feature makes possible either burst release of an encapsulated hydrophobic species from disintegrated micelles by UV light, or slow release by the action of a reducing agent, or release with combined fast-slow rate profiles using the two stimuli

Diverse Thermoresponsive Behaviors of Uncharged UCST Block Copolymer Micelles in Physiological Medium

Three amphiphilic diblock copolymers, representative of three types of block copolymer (BCP) design, were synthesized using reversible addition–fragmentation chain-transfer (RAFT) polymerization. All of them have a same uncharged block of a random copolymer of commercially available acrylamide and acrylonitrile, P­(AAm-<i>co</i>-AN), and exhibit a composition-tunable upper critical solution temperature (UCST). We show that by coupling a common P­(AAm-<i>co</i>-AN) block with either hydrophobic polystyrene (PS) or hydrophilic poly­(dimethylacrylamide) (PDMA) or the lower critical solution temperature (LCST) polymer of poly­(<i>N,N</i>-dimethylaminoethyl methacrylate) (PDMAEMA), the BCP micelles formed in water or in phosphate buffered saline (PBS) can display diverse and UCST-dictated changes in response to temperature variations, such as the reversible dispersion-aggregation of micelles, dissolution-formation of micelles, and reversal of micelle core and corona. The results point out that P­(AAm-<i>co</i>-AN) is a robust UCST polymer that can be introduced into controlled polymer architectures producible by RAFT, the same way as using the extensively studied LCST counterparts like poly­(<i>N</i>-isopropylacrylamide) (PNIPAM). This ability should make the door wide open to exploring new thermosensitive polymers based on the thermosensitivity opposite to the LCST

General Strategy for Making CO₂-Switchable Polymers

By discovering that poly­(<i>N</i>,<i>N</i>-dimethylaminoethyl methacrylate) (PDMAEMA) in water can react with carbon dioxide (CO₂) and have its lower critical solution temperature (LCST) reversibly tuned by passing CO₂ and argon (Ar) through the solution, we describe a general strategy for imparting a CO₂-switchable LCST or water solubility to polymers of broad interest like poly­(<i>N</i>-isopropylacrylamide) (PNIPAM) and poly­[2-(2-methoxyethoxy)­ethyl methacrylate] (PMEO₂MA). We show that by easy copolymerization incorporating DMAEMA as a CO₂-responsive trigger into PNIPAM or PMEO₂MA, their LCST can effectively be switched by the gases. Two examples of applications were further demonstrated: upon CO₂ or Ar bubbling at a constant solution temperature, hydrogels could undergo a reversible volume transition and block copolymer micelles could be dissociated and reassembled. This study opens the door to a wide range of easily accessible CO₂-switchable polymers, enabling the use of CO₂ as an effective trigger for smart materials and devices

CO₂‑Responsive Polymer Single-Chain Nanoparticles and Self-Assembly for Gas-Tunable Nanoreactors

CO₂-responsive polymer single-chain nanoparticles (SCNPs) and self-assembled micellar aggregates are investigated as gas-controlled, rate- and size-tunable nanoreactors of gold nanoparticles (AuNPs). On one hand, SCNPs are prepared from a random copolymer of poly­{(<i>N</i>,<i>N</i>-dimethylaminoethyl methacrylate)-<i>co</i>-4-methyl-[7-(methacryloyl)­oxy-ethyl-oxy]­coumarin} (P­(DMAEMA-<i>co</i>-CMA)). When dispersed in aqueous solution, individual nanoparticles can undergo reversible swelling/shrinking under alternating CO₂/N₂ stimulation as a result of the reversible protonation/deprotonation of tertiary amine groups. On the other hand, tadpole-like single-chain “Janus” nanoparticles (SCJNPs) are prepared using an amphiphilic diblock copolymer of PS-<i>b</i>-P­(DMAEMA-<i>co</i>-CMA) (PS is hydrophobic polystyrene). This type of SCJNPs can self-assemble into core–shell micellar aggregates in aqueous solution. Under CO₂/N₂ stimulation, the collective swelling/shrinking of SCJNPs within the micelle results in large, reversible volume change. Both P­(DMAEMA-<i>co</i>-CMA) SCNPs and PS-<i>b</i>-P­(DMAEMA-<i>co</i>-CMA) SCJNP micelles are explored as gas-tunable nanoreactors for AuNPs. The rate of AuNP formation increases under CO₂ stimulation and decreases upon N₂ bubbling, which makes it possible to tune the reaction rate up and down (on/off switching) by using the two gases. Moreover, using the micelles of SCJNPs, whose volume can be controlled over a wide range by adjusting the CO₂ stimulation strength, variable-size AuNPs and their aggregates are obtained with continuous redshift of the surface plasmon resonance (SPR) into the long-wavelength visible light region

CO₂‑Responsive Polymer Single-Chain Nanoparticles and Self-Assembly for Gas-Tunable Nanoreactors

CO₂-responsive polymer single-chain nanoparticles (SCNPs) and self-assembled micellar aggregates are investigated as gas-controlled, rate- and size-tunable nanoreactors of gold nanoparticles (AuNPs). On one hand, SCNPs are prepared from a random copolymer of poly­{(<i>N</i>,<i>N</i>-dimethylaminoethyl methacrylate)-<i>co</i>-4-methyl-[7-(methacryloyl)­oxy-ethyl-oxy]­coumarin} (P­(DMAEMA-<i>co</i>-CMA)). When dispersed in aqueous solution, individual nanoparticles can undergo reversible swelling/shrinking under alternating CO₂/N₂ stimulation as a result of the reversible protonation/deprotonation of tertiary amine groups. On the other hand, tadpole-like single-chain “Janus” nanoparticles (SCJNPs) are prepared using an amphiphilic diblock copolymer of PS-<i>b</i>-P­(DMAEMA-<i>co</i>-CMA) (PS is hydrophobic polystyrene). This type of SCJNPs can self-assemble into core–shell micellar aggregates in aqueous solution. Under CO₂/N₂ stimulation, the collective swelling/shrinking of SCJNPs within the micelle results in large, reversible volume change. Both P­(DMAEMA-<i>co</i>-CMA) SCNPs and PS-<i>b</i>-P­(DMAEMA-<i>co</i>-CMA) SCJNP micelles are explored as gas-tunable nanoreactors for AuNPs. The rate of AuNP formation increases under CO₂ stimulation and decreases upon N₂ bubbling, which makes it possible to tune the reaction rate up and down (on/off switching) by using the two gases. Moreover, using the micelles of SCJNPs, whose volume can be controlled over a wide range by adjusting the CO₂ stimulation strength, variable-size AuNPs and their aggregates are obtained with continuous redshift of the surface plasmon resonance (SPR) into the long-wavelength visible light region

Two-Way CO₂‑Switchable Triblock Copolymer Hydrogels

CO₂-responsive ABA triblock copolymer hydrogels are described. Through rational block copolymer design, these hydrogels could undergo either CO₂-induced gel-to-sol or the reverse sol-to-gel transition. While the middle block B is water-soluble, the solubility of the two end blocks A can be switched by CO₂. For the gel-to-sol transition, the A block was made to have a lower critical solution temperature (LCST) that can increase upon CO₂ bubbling, while for the sol-to-gel transition, the A block was designed to have a LCST that decreases with CO₂. Repeated cycles of hydrogel formation and dissociation could be achieved by simply passing CO₂ and an inert gas alternately through the solution, at a constant temperature and without adding acids and bases for pH change. Moreover, CO₂-induced release of an encapsulated protein was demonstrated

DataSheet_1_Single cell meta-analysis of EndMT and EMT state in COVID-19.pdf

COVID-19 prognoses suggests that a proportion of patients develop fibrosis, but there is no evidence to indicate whether patients have progression of mesenchymal transition (MT) in the lungs. The role of MT during the COVID-19 pandemic remains poorly understood. Using single-cell RNA sequencing, we profiled the transcriptomes of cells from the lungs of healthy individuals (n = 45), COVID-19 patients (n = 58), and idiopathic pulmonary fibrosis (IPF) patients (n = 64) human lungs to map the entire MT change. This analysis enabled us to map all high-resolution matrix-producing cells and identify distinct subpopulations of endothelial cells (ECs) and epithelial cells as the primary cellular sources of MT clusters during COVID-19. For the first time, we have identied early and late subgroups of endothelial mesenchymal transition (EndMT) and epithelial-mesenchymal transition (EMT) using analysis of public databases for single-cell sequencing. We assessed epithelial subgroups by age, smoking status, and gender, and the data suggest that the proportional changes in EMT in COVID-19 are statistically significant. Further enumeration of early and late EMT suggests a correlation between invasive genes and COVID-19. Finally, EndMT is upregulated in COVID-19 patients and enriched for more inflammatory cytokines. Further, by classifying EndMT as early or late stages, we found that early EndMT was positively correlated with entry factors but this was not true for late EndMT. Exploring the MT state of may help to mitigate the fibrosis impact of SARS-CoV-2 infection.</p