Charge-transfer (CT) states, bound combinations of an electron and a hole on separate molecules, play a crucial role in organic optoelectronic devices. We report direct nanoscale imaging of the transport of long-lived CT states in molecular organic donor-acceptor blends, which demonstrates that the bound electron-hole pairs that form the CT states move geminately over distances of 5-10 nm, driven by energetic disorder and diffusion to lower energy sites. Magnetic field dependence reveals a fluctuating exchange splitting, indicative of a variation in electron-hole spacing during diffusion. The results suggest that the electron-hole pair of the CT state undergoes a stretching transport mechanism analogous to an 'inchworm' motion, in contrast to conventional transport of Frenkel excitons. Given the short exciton lifetimes characteristic of bulk heterojunction organic solar cells, this work confirms the potential importance of CT state transport, suggesting that CT states are likely to diffuse farther than Frenkel excitons in many donor-acceptor blends.

A stretchable transparent double network ionogel composed of physically cross-linked poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDFco-HFP)) and chemically cross-linked poly(methyl methacrylate-co-butylmethacrylate) (P(MMA-co-BMA)) elastomer networks within [EMIM][TFSI] ionic liquid was fabricated through a facile one-pot thermal polymerization. The dualnetwork (DN) ionogel presents good mechanical performance (failure tensile stress 2.31 MPa, strain 307%) with a high loading of ionic liquid (70 wt %) for achieving required ionic conductivity (>0.1 S/m at room temperature). The transparent chemical cross-linked P(MMA-co-BMA) elastomer network endows high transparency (>93%) and high stretchability to the DN ionogel. The DN ionogel maintains good toughness, elasticity, and transparency in a wide temperature range (−40 to 80 °C) for the application in a harsh environment. In addition, the sensitivity of the DN ionogel to the change of environment temperature and deformation was detected and described. The practical potential of the DN ionogel in flexible electronic devices is further revealed by fabricating DN ionogel strain sensors to detect the movement of different human limbs including the bending of the finger, wrist, and elbow as well as the slight throat jitter during the swallowing and vocalization, showing fast response, high sensitivity, and good repeatability.

This meta-analysis suggested that green tea had favorable effects, ie, decreased fasting glucose and Hb A1c concentrations. Subgroup analyses showed a significant reduction in fasting insulin concentrations in trials with high Jadad scores.

As a new two-dimensional material similar to graphene, MXene has attracted extensive attention in the field of electrochemical materials such as supercapacitors because of its excellent mechanical properties, electrical conductivity, and thermal conductivity. What is better than graphene is that the few-layer MXene material obtained by proper treatment has good water dispersibility and can be used as an ideal nanomaterial to enhance the conductivity of hydrogels. However, the articles about the few-layer MXene material used in the preparation of composite hydrogels are rare. In this paper, MXene was synthesized by Yury mild method. Poly­(N-isopropyl acrylamide) (PNIPAM) hydrogel and physical cross-linking hydrogel were used as the matrix to prepare composite hydrogels with temperature sensitivity and stress-sensing properties. The composite hydrogels exhibited excellent mechanical properties: it could be stretched to over 14 times the original length and achieved a 0.4 MPa tensile strength while showing good self-healing ability, which was of great significance for the practical application of hydrogels. The conductivity of the composite hydrogel was 1.092 S/m, which was about 15 times that of the control hydrogel without MXene. The potential of the composite hydrogel as a smart compression sensor was also verified by the conductivity tests.

A remarkably rich variety of nanophase-separated structures and various order–order transitions are observed in a series of low-molecular weight (MW) rod–coil block copolymers (BCPs) with the rod blocks of different lengths (L Rod’s). The rod–coil diblock copolymer studied herein is poly(dimethylsiloxane)-b-poly{2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene} (PDMS-b-PMPCS), in which PMPCS is a rod-like polymer and exhibits an MW-dependent liquid crystalline (LC) phase behavior. When the polymerization degree of the PMPCS rod block (N Rod) is less than 32 (L Rod < 8 nm), the PMPCS block is always amorphous in the entire temperature range. And the corresponding PDMS-b-PMPCS BCPs with N Rod from 11 to 29 and the volume fraction of the PMPCS rod (f Rod) from 43% to 67% self-assemble into various equilibrium nanostructures after annealed at temperatures above the glass transition temperatures of the PMPCS blocks. When N Rod = 11 and f Rod = 43%, the BCP forms a lamellar structure (LAM); when N Rod = 15 and f Rod = 51%, the BCP forms a double gyriod structure (GYR) ; when N Rod = 20 and f Rod = 57%, the BCP forms a GYR structure after annealed below 180 °C and transforms to the Fddd structure after annealed above 180 °C; when N Rod = 29 and f Rod = 67%, the nanostructure of the BCP after annealed below 180 °C is hexagonally packed cylinders (HEX) and changes to a body centered cubic structure (BCC) after annealed above 180 °C. When N Rod > 32 (L Rod > 8 nm), the PMPCS rod block is amorphous at low temperatures and transforms to a stable columnar LC phase after annealed at high temperatures. Correspondingly, the PDMS-b-PMPCS BCP with N Rod = 44 and f Rod = 75% forms a HEX structure after annealed at lower temperatures at which the PMPCS block is amorphous, and the nanostructure transforms to LAM after the sample is annealed at higher temperatures at which the PMPCS block enters into the LC phase. Therefore, only by a small change of the rod length in the low-MW PDMS-b-PMPCS rod–coil BCPs, various nanostructures including LAM, GYR, Fddd, HEX, and BCC are obtained. In addition, by increasing annealing temperatures, GYR-to-Fddd and HEX-to-BCC transitions are observed in the BCPs with the amorphous PMPCS, and a HEX-to-LAM transition occurs in the BCP when the LC PMPCS block undergoes an isotropic-to-LC phase transformation.