Cupric chloride

The current rates of production and consumption of electronic devices have made the generation of electronic waste a global concern.Waste printed circuit boards (WPCBs) are the core component of elec. waste.A proper management of WPCBs is crucial from both, an environmental point of view (they contain toxic materials) and an economic point of view since they contain valuable materials such as precious metals (PMs).The heterogeneity in WPCBs composition hampers the effective recovery of the valuable metals contained in WPCBs, making it essential to adopt a combined approach such as the inclusion of a chem. pretreatment to recover the materials that they contain.This work studies the effect of the chem. pretreatment, Fe²⁺ and Cl^- concentrations on the recovery yield and the kinetics of the leaching of Cu, Au and Ag, during the electrochem. treatment of real WPCBs.This study aims to assess the viability of using waste spent pickling acids (SPAs) from surface treatment industries to recover valuable materials from WPCBs by electrochem. leaching.Two full 2² factorial designs were considered: the first design evaluated the effect of Cl^- and Fe²⁺ concentrations, while the second design studied the effect of the chem. pretreatment and Cl^- concentrationA novel inhouse leaching system was used.Operating at room temperature with a mildly acidic media (0.05 M H₂SO₄), the system achieved leaching yields up to 99 %, 75 % and 99 % for Cu, Au, and Ag, resp.These recoveries were reached in less than 150 min for Cu and Ag and less than 60 min for Au.Based on the results, a sequential and environmentally friendly recovery process was proposed to recover sep. base and PMs from WPCBs.

Metallic nanowires have served as novel materials for soft electronics due to their outstanding mechanical compliance and electrical properties. However, weak adhesion and low mechanical robustness of nanowire networks to substrates significantly undermine their reliability, necessitating the use of an insulating protective layer, which greatly limits their utility. Herein, we present a versatile and generalized laser-based process that simultaneously achieves strong adhesion and mechanical robustness of nanowire networks on diverse substrates without the need for a protective layer. In this method, the laser-induced photothermal energy at the interface between the nanowire network and the substrate facilitates the interpenetration of the nanowire network and the polymer matrix, resulting in mechanical interlocking through percolation. This mechanism is broadly applicable across different metallic nanowires and thermoplastic substrates, significantly enhancing its universality in diverse applications. Thereby, we demonstrated the mechanical robustness of nanowires in reusable wearable physiological sensors on the skin without compromising the performance of the sensor. Furthermore, enhanced robustness and electrical conductivity by the laser-induced interlocking enables a stable functionalization of conducting polymers in a wet environment, broadening its application into various electrochemical devices.