Life-Cycle Assessment of Various Synthesis Routes of Silver Nanoparticles

Abstract

The current study evaluated the environmental impacts caused due to different synthesis routes of Ag NPs using life cycle analysis. Silver nanoparticles (Ag NPs) have been studied extensively in the past due to their unique physical, chemical, antibacterial and anti-fungal properties. The study was aimed to identify the environmental hot spots due to system variables like Ag NPs synthesis route, its application (on socks) and its disposal into environment (water) from a life-cycle assessment (LCA) perspective. Presently, various synthesis methods of Ag NPs (physical, chemical and biological methods) are available for fabrication of different size distributions. A life cycle study on different synthesis routes (microwave-assisted, green synthesis and laser ablation method) of Ag NPs was carried out to assess the impacts on the environment due to fabrication of NPs. This was assessed with the help of LCA tool (SimaPro), and the assessment was performed at midpoint levels using ReCIPe method. When evaluating the results from the LCA study, we observed that the synthesis of NP is dominated by the environmental impacts associated with energy and chemical use, especially relevant for the type of synthesis method used. After coating a cotton sock with the synthesised Ag NPs, it can be seen that about 90% contribution towards FEU and MEU is due to the production of Ag NPs coated socks, and nearly 50% of the contribution towards TET is caused by transportation. In terms of various factors, Ag NPs synthesised using non-renewable energy (grid) have more impact compared to renewable source (solar).