Li-Ion Transfer Mechanism of Gel Polymer Electrolyte with Sole Fluoroethylene Carbonate Solvent.

Although gel polymer electrolytes (GPEs) represent a promising candidate to address the individual limitations of liquid and solid electrolytes, their extensive development is still hindered due to the veiled Li-ion conduction mechanism. Herein, the related mechanism in GPEs is extensively studied by developing an in situ polymerized GPE comprising fluoroethylene carbonate (FEC) solvent and carbonate ester segments (F-GPE). Practically, although with high dielectric constant, FEC fails to effectively transport Li ions when acting as the sole solvent. By sharp contrast, F-GPE demonstrates superior electrochemical performances, and the related Li-ion transfer mechanism is investigated using molecular dynamics simulations and 7 Li/6 Li solid-state nNMR spectroscopy. The polymer segments are extended with the swelling of FEC, then an electron-delocalization interface layer is generated between abundant electron-rich groups of FEC and the polymer ingredients, which works as an electron-rich "Milky Way" and facilitates the rapid transfer of Li ions by lowering the diffusion barrier dramatically, resulting in a high conductivity of 2.47 × 10-4  S cm-1 and a small polarization of about 20 mV for Li//Li symmetric cell after 8000 h. Remarkably, FEC provides high flame-retardancy and makes F-GPE remains stable under ignition and puncture tests.

The use of quartz crystal microbalance with dissipation (QCM-D) for studying nanoparticle-induced platelet aggregation.

Interactions between blood platelets and nanoparticles have both pharmacological and toxicological significance and may lead to platelet activation and aggregation. Platelet aggregation is usually studied using light aggregometer that neither mimics the conditions found in human microvasculature nor detects microaggregates. A new method for the measurement of platelet microaggregation under flow conditions using a commercially available quartz crystal microbalance with dissipation (QCM-D) has recently been developed. The aim of the current study was to investigate if QCM-D could be used for the measurement of nanoparticle-platelet interactions. Silica, polystyrene, and gold nanoparticles were tested. The interactions were also studied using light aggregometry and flow cytometry, which measured surface abundance of platelet receptors. Platelet activation was imaged using phase contrast and scanning helium ion microscopy. QCM-D was able to measure nanoparticle-induced platelet microaggregation for all nanoparticles tested at concentrations that were undetectable by light aggregometry and flow cytometry. Microaggregates were measured by changes in frequency and dissipation, and the presence of platelets on the sensor surface was confirmed and imaged by phase contrast and scanning helium ion microscopy.