Co-functional Group Conducting Hydrogels Inspired by Ligament for Flexible Electronic Devices.

The application of conductive hydrogels in flexible electronics has attracted much interest in recent years due to their excellent mechanical properties and conductivity. However, the development of conductive hydrogels combining with superior self-adhesion, mechanical properties, antifreeze, and antibacterial activity is still a challenge. Herein, inspired by the structure of the ligament, a multifunctional conductive hydrogel is constructed to address the issue by introducing collagen into the polyacrylamide. The obtained conductive hydrogel exhibits outstanding conductivity (52.08 mS/cm), ultra-stretchability (>2000%), self-adhesion, and antibacterial properties. More significantly, the supercapacitor based on this hydrogel electrolyte achieves a desirable capacitance (514.7 mF·cm-2 at 0.25 mA·cm-2 current density). As a wearable strain sensor, the obtained hydrogel can rapidly detect different movements of the body such as finger, wrist, elbow, and knee joints. It is conceived that this study would provide a potential approach for the preparation of conductive hydrogels in the application of flexible electronics.

Appropriate solvent NaVO3 for composition analysis of LiNbO3 crystal using chemical method.

It is crucial to find an appropriate solvent for composition analysis of LiNbO(3) crystal by a chemical method, such as inductively coupled plasma atomic emission spectroscopy. We have comparatively studied several solvents for LiNbO(3) crystal, including HF acid, KHSO(4), B(2)O(3), LiBO(2), and NaVO(3). The results show that as the NaVO(3) is used as the solvent, the solubility of LiNbO(3) is as high as 1 g/g at 1000 °C. The dissolving is quite fast. Neither solute nor solvent is lost from the melting during the dissolving procedure. A clear high-concentration solution is obtained. Moreover, it is verified experimentally that such a solution is valid for composition analysis of LiNbO(3) crystal by a chemical method. In contrast, the other solvents suffer from one problem or another. We conclude that NaVO(3) is an appropriate solvent for chemical analysis of LiNbO(3).

Influence of postgrowth Li-poor vapor-transport equilibration on the surface Li2O content of a congruent LiNbO3 crystal.

The influence of Li-poor vapor-transport equilibration (VTE) on the surface Li(2)O content of initially congruent X- and Z-cut LiNbO(3) crystal plates was studied against the VTE temperature and time. The VTE-induced surface-Li(2)O-content reduction was evaluated from the measured birefringence. The results show that the reduction and VTE temperature follow the traditional Arrhenius law with a surface-Li(2)O-content alteration constant of (1.0 ± 0.2) × 10(8)/(1.6 ± 0.2) × 10(10) mol % and an activation energy (2.2 ± 0.2)/(2.8 ± 0.2) eV for the X/Z-cut plate, and the reduction has a square-root dependence on the VTE time, ΔC(X) = 0.15t(0.5) for the X-cut plate and ΔC(Z) = 0.167t(0.5) for the Z-cut plate. A generalized empirical expression that relates the reduction to both the VTE temperature and duration is presented. The expression is useful for producing an off-congruent, Li-deficient LiNbO(3) plate with the desired surface Li(2)O content via adjustment of the VTE temperature and duration. On the basis of the known VTE time dependence on the surface-Li(2)O-content reduction, a solution to the Li(+) out-diffusion equation, an integral of the error function complement, is obtained and verified by previously reported experimental results. The results also show that the VTE displays slight anisotropy and is slightly faster along the optical axis direction of the crystal. The Li-poor VTE is a slow process. At 1100 °C, the Li-poor VTE time required for the surface Li(2)O content reaching the Li-deficient boundary is about 400/323 h for the X/Z-cut plate.