With the widespread use of personal electronic devices, excessive blue light exposure that causes retinal cell damage and skin hyperpigmentation has attracted increasing attention. However, an effective indicator for real-time in-house monitoring of blue light is still lacking. In this study, we developed a screen-attachable visual hydrogel indicator for facile in-house monitoring of blue light. The indicator is fabricated by encapsulating both a blue light-responsive photosensitizer (fluorescein) and 3,3′,5,5′-tetramethylbenzidine (TMB) within an agarose hydrogel. Upon exposure to blue light, the photosensitizer generates reactive oxygen species (ROS), which oxidize colorless TMB to blue oxTMB. The proximity of fluorescein and TMB within the hydrogel nanopores significantly facilitates the oxidation reaction. Hence, using a hydrogel as the reaction carrier not only makes the indicator screen-attachable but also greatly enhances its sensitivity. The color change of TMB is good linearly with the blue light doses in the range of 0.15–1.2 J/cm2 with a detection limit about 0.082 J/cm2, much lower than the threshold (0.75 J/cm2) for oxidative eye stress. Green and red light from the electronic products caused no interference for the monitoring of blue light. It was successfully applied for monitoring the cumulative dose of blue light emitted from the three types of electronic products (i.e., laptops, tablets, and light-emitting diode (LED) lamps) by simply attaching the indicator on the screen or on the desk. This hydrogel indicator, with the merits of screen-attach ability, facile use, and high sensitivity, is quite appealing for in-house monitoring of blue light from electronic products.
Waste electrical and electronic equipment (WEEE) contains various valuable metals, making it a potential secondary resource for sustainable metal usage. Pyrometallurgical smelting is an efficient technique to recycle WEEE by extracting precious metals into copper matte and removing impurities into slags. The impact of WEEE impurities such as CaO and Al2O3on the phase compositions of the smelting products attracts great attention for industrial metal recovery. This study clarified the impact of CaO and Al2O3on the equilibrium phase compositions of copper matte and SiO2-saturated FeOx-SiO2-Al2O3-CaO slags. The high-temperature smelting experiments were taken at a controlled p(SO2) of 0.1 atm and 1300 °C, followed by quenching and electron probe microanalysis. The results showed that the copper and sulfur in the smelting system were highly deported into copper matte, and their distribution in matte was enhanced by increasing CaO and Al2O3concentrations introduced by WEEE. The chemical copper dissolution in slags increased with increasing matte grade but decreased by adding CaO and Al2O3. The iron was preferentially concentrated in slags, and higher matte grades improved the iron distribution in slags. The current experimental results enrich fundamental thermodynamic data and help optimize WEEE smelting operations for efficient recovery of valuable metals.
Qian Wang,Bingang Xu,Di Tan,Xin Hu,Yujue Yang,Junxian Huang,Yuanyuan Gao,Xinlong Liu
Silk has recently demonstrated a promising application potential in wearable electronic devices owing to its attractive electron affinity. However, natural silk possesses poor extensibility, and fabricating high-performance silk-based triboelectric nanogenerators (TENGs) remains a challenge. In this paper, we propose a new method to construct the fibroin (SF)/sericin (SS)/polyvinyl alcohol (PVA)/silver nanowires (AgNWs)/fluoro-nylon-TENG (FSPAG/F-TENG), which simultaneously achieves high electric outputs and remarkable flexibility with long-lasting durability. By employing SS rich in the amorphous domain and AgNWs with high electric conductivity , our proposed FSPAG/F-TENG can achieve a maximum voltage of 745 V and a current of 22.5 μA with a size of 2 × 2 cm 2 at a load of 5 N at 3 Hz. This results in an ultrahigh power density of 760 μW/cm 2 , which exceeds most silk-based TENGs reported recently. We also analyze the potential mechanism of enhanced electrical outputs. The constructed device not only demonstrates desirable mechanical performance like excellent flexibility, extensibility, and wear-resistant after 30,000 cycles but also possesses self-sensing capabilities, making it an intelligent device for monitoring human gestures and powering various commercial electronics.
危险品化学品经营许可证（带存储）