A Silver Key to Polymer Synthesis: The Role of Metallic Silver in the Preparation of Functional Polymers, Coatings, and Materials

Silver is among the less frequently employed zerovalent metals as a reducing agent in atom transfer radical polymerization (ATRP), primarily due to its relatively mild reducing capacity. Silver generally exists in two oxidation states (0 and +1), which effectively minimizes undesirable side reactions. This review summarizes the recent advances in the application of metallic silver in ATRP. The application of Ag0 as a reducing agent has enabled the synthesis of polymers with narrow molecular weight distributions Đ ≤ 1.1 and the preparation of functional polymers, incorporating isocyanate groups, perfluorophenyl rings, or succinimide moieties, synthesis of branched, star, and bottlebrush polymers, and the modification of organic surfaces. Additionally, Ag-containing nanocrystals with photocatalytic activity have also been employed in visible-light-driven, metal-free ATRP. Furthermore, silver nanoparticles (AgNP) and thin films have been successfully functionalized to enhance their dispersibility in both aqueous and organic solvents, and enable the fabrication of highly sensitive humidity sensors.