An electrochemical method to rapidly assess the environmental risk of silver release from nanowire transparent conductive films

Abstract

Silver nanowires (AgNW) are new nanomaterials designed to be incorporated into transparent conductive films in electronics, microelectrodes, heated surfaces and others. Although in these films, the AgNW are generally protected by a coating material, a risk for release of silver at all stages of the nanoproduct life cycle does exist due to corrodibility of the metal. Since ionic and nanoparticulate Ag represent a toxicological risk for a large number of living cells, there is a need for quantifying the potential Ag release from these product components. We developed an electrochemical method to evaluate possible corrosion activity of silver in AgNW transparent conductive films (TCFs) and concomitant Ag + release. A polysiloxane polymer was used as protective coating of AgNW TCFs. A consistent correlation is observed between the degree of corrosion and the coatings' characteristics, in particular the thicknesses. A major advantage of the new approach, compared to classical aging studies, is the short experimentation time: 20 min are sufficient for a diagnostic result. The method is an accelerated corrosion and release test. It is green methodology with use of very low electric power and with no harmful reagents. A particularly attractive application could be in the field of environmental risk assessment of metals from portable electronics and biosensors.

Advances in Flexible Metallic Transparent Electrodes

“…[ 182 ] Finally, an interesting approach to rapidly diagnose the environmental risk of metal release from TEs in optoelectronic devices was recently reported by Omaña‐Sanz et al. [ 183 ]…”

“…[181] Moreover, Han et al demonstrated a "nanorecycling" approach using a laser-induced selective photothermochemical reduction, to restore oxidized Cu to a metallic state for repetitive reuse. [182] Finally, an interesting approach to rapidly diagnose the environmental risk of metal release from TEs in optoelectronic devices was recently reported by Omaña-Sanz et al [183] One of the main physical parameters of MNW networks is their density: below a critical density, η c , there is no percolation (i.e., no pathways for conducting free charges between the two opposite electrodes at each side of the network). [184] This critical density is related to the "2D stick percolation theory" and has been investigated via Monte Carlo simulations and experimental approaches.…”

Recent advancements in transparent carbon nanotube films: chemistry and imminent challenges

“…ITO has unique features besides a sheet resistance of 10 Ω sq −1 at around 90% visual transmission, shows excellent durability and adaptability through equally wet and dry equipment methods. Though, expected optoelectronics need TCF substances those are mechanically flexible, insubstantial and lower assembly price [6][7][8][9][10]. The increasing market toward ITO owing to the growth of solar cells can drive to an improvement in the price.…”