Computational modelling and microfluidics as emerging approaches to synthesis of silver nanoparticles – a review

This review provides an integrated overview of the current state of knowledge for sustainable production of silver nanoparticles (AgNPs), focussing on recent advances in their synthesis using emerging microfluidic-based methods and computational modelling, their properties and practical applications. Special attention is given to the Finke-Watzky two-step kinetic model, which provides the best fitting for nucleation and growth of AgNPs and the multiple operating parameters that affect their physical and chemical properties. An overview of numerical simulations used to model the synthesis of AgNPs across different length and time scales is presented. Investigations made at the molecular scale via molecular dynamics (MD) simulations, at the meso- and macroscale via population balance modelling (PBM) and computational fluid dynamics (CFD), respectively are discussed, alongside data-driven modelling approaches. The review also identifies both limitations and advantages in exploiting the aforementioned techniques, offering a way forward for further investigations on the topic. A critical analysis of the literature leads to confirm that the combination of microfluidics-based synthesis, which enable reactions to be carried out under highly-controlled conditions, along with physics-driven simulations and data-driven models are a powerful tool to effectively link input information of the process and output data related to the properties of the AgNPs. This combined framework therefore provides an opportunity to improve the prediction accuracy of the whole cycle of synthesis of AgNPs and overcome the environmental impact and limitations of traditional methods.