Solid Polymer Electrolyte with High Ionic Conductivity via Layer-by-Layer Deposition

A novel multilayer system via layer-by-layer (LbL) self-assembly by alternatively packing polyethylene glycol (PEG)−α-cyclodextrin (αCD) complex and poly­(acrylic acid) (PAA) via hydrogen-bonding is designed and investigated in this work. The PEG-αCD inclusion complex is obtained by supramolecular interaction. Multilayer films with different ratios of αCD are fabricated, and the growth behavior, morphology, thermal properties, and electrical properties of the resultant LbL films are systematically characterized. The films with PEG-αCD complex and PAA as building blocks show high ionic conductivity reaching up to 2.5 × 10^–5 S cm^–1 under room temperature (52%RH), which is almost two orders magnitude higher than the PEG/PAA films under the same conditions. The PEG-αCD₁₅/PAA films also possess high water retention due to the large amounts of hydroxyl groups carried by αCD, which enables the films, after being exposed to a high humidity environment, to maintain a high ionic conductivity under a low humidity environment. This PEG-αCD/PAA LbL system provides an insight for designing polymer based solid state electrolyte and its application toward electrochemical devices

Image_1_The Binding Mechanism Between Inositol Phosphate (InsP) and the Jasmonate Receptor Complex: A Computational Study.TIF

<p>Jasmonates are critical plant hormones, mediating stress response in plants and regulating plant growth and development. The jasmonate receptor is a multi-component complex, composed of Arabidopsis SKP-LIKE PROTEIN1 (ASK1), CORONATINE INSENSITIVE 1 (COI1), inositol phosphate (InsP), and jasmonate ZIM-domain protein (JAZ). COI1 acts as multi-component signaling hub that binds with each component. InsP is suggested to play important roles in the hormone perception. How InsP binds with COI1 and the structural changes in COI1 upon binding with InsP, JA-Ile, and JAZ are not well understood. In this study, we integrated multiple computational methods, such as molecular docking, molecular dynamics simulations, residue interaction network analysis and binding free energy calculation, to explore the effect of InsP on the dynamic behavior of COI1 and the recognition mechanism of each component of the jasmonate receptor complex. We found that upon binding with InsP, JA-Ile, and JAZ1, the structure of COI1 becomes more compact. The binding of InsP with COI1 stabilizes the conformation of COI1 and promotes the binding between JA-Ile or JAZ1 and COI1. Analysis of the network parameters led to the identification of some hub nodes in this network, including Met88, His118, Arg120, Arg121, Arg346, Tyr382, Arg409, Trp467, and Lys492. The structural and dynamic details will be helpful for understanding the recognition mechanism of each component and the discovery and design of novel jasmonate signaling pathway modulators.</p

Combining ZnO and Organosilica Nanodots as a Thick Cathode Interlayer for Highly Efficient and Stable Inverted Polymer Solar Cells

Low-work-function metal oxides as cathode interlayers are widely used in polymer organic solar cells (PSCs), but the surface defect and intrinsic photocatalysis issues severely affect the high efficiency, thickness insensitivity, and stability of PSCs. In this work, we used organosilica nanodots (OSiNDs) to modify ZnO as cathode interlayers via the self-assembly method. The ZnO/OSiNDs bilayer can acquire a suitable work function and a high conductivity of 5.87 × 10–4 S m–1. Through systematic studies, there is stable surface coordination interaction of Zn–N bonding between ZnO and OSiNDs. In i-PSCs, using D18:Y6 as the active layer, the ZnO/OSiNDs-based device achieves the best PCE of 17.87%. More importantly, due to the high conductivity, the PCE for the device based on a 68 nm thick ZnO/OSiNDs interlayer is still high up to 16.53%, while the PCE for the device based on a 66 nm thick ZnO interlayer is only 13.18%. For photostability, the PCE of the device based on the ZnO/OSiNDs interlayer maintains 95% of its original value after continuous AM 1.5G illumination (contains UV light) at 100 mW/cm2 for 600 min, while that of the ZnO-based device only maintains 72% of the original value. This work suggests that ZnO/OSiNDs can be utilized as a cathode interlayer to fabricate highly efficient and stable PSC over a wide range of thicknesses

Effect of Host–Guest Interactions on the Cloud Points of Neutral Thermosensitive Homopolymers: Poly(<i>N</i>-n-propylmethacrylamide) and Polymers with Similar Structures

We investigated effect of cyclodextrins (CDs) on the cloud point of several thermosensitive polymers that are not ionizable. α-CD increased the cloud point of the poly­(<i>N</i>-n-propylmethacrylamide) (PnPMAm) aqueous solution; by contrast, β-CD or γ-CD did not affect the cloud point of the PnPMAm solution. The cloud point of the PnPMAm solution increased gradually with an increase in the concentration of α-CD. Furthermore, we compared the effect of the CDs on the cloud points of four polymers with similar structures. As for poly­(<i>N</i>-isopropylacrylamide) (PiPAAm), neither α-CD nor β-CD affected its cloud point. On the basis of the effect of the differently sized CDs on the cloud point of five polymers and the corresponding NOESY NMR data, we inferred that steric hindrance by the main chain of PiPAAm might be responsible for the bulky CD being unable to form a complex with the short isopropyl group

Stretchable and Wearable Electrochromic Devices

Stretchable and wearable WO₃ electrochromic devices on silver nanowire (AgNW) elastic conductors are reported. The stretchable devices are mechanically robust and can be stretched, twisted, folded, and crumpled without performance failure. Fast coloration (1 s) and bleaching (4 s) time and good cyclic stability (81% retention after 100 cycles) were achieved at relaxed state. Proper functioning at stretched state (50% strain) was also demonstrated. The electrochromic devices were successfully implanted onto textile substrates for potential wearable applications. As most existing electrochromic devices are based on rigid technologies, the innovative devices in their soft form hold the promise for next-generation electronics such as stretchable, wearable, and implantable display applications