A Silver(I) Coordination Complex as a Reinforcing Antibacterial Agent for Cellulose Nanocrystal Cryogels

: Cellulose nanocrystal (CNC)-based materials are promising sustainable alternatives for numerous applications, and enhancing their mechanical robustness while imparting antimicrobial activity could further broaden their utility. Here, the Ag(I) coordination complex [(ina)2Ag]NO3 (ina = isonicotinic acid) is introduced as a multifunctional additive for CNC materials. The complex was synthesized via a simple liquid-assisted grinding approach with full conversion and quantitative yield and incorporated into CNC suspensions under mild conditions. Its addition promotes attractive interparticle interactions, leading to a more cohesive CNC network. Consequently, the resulting cryogels exhibit a more compact morphology and a greater than 2-fold increase in compressive modulus compared to pristine CNC cryogels. In contrast, analogous systems containing AgNO3 show negligible mechanical improvement, highlighting the importance of the coordination environment. Furthermore, CNC materials containing [(ina)2Ag]NO3 display broad-spectrum antimicrobial activity. These findings establish coordination compounds as multifunctional additives capable of reinforcing CNC materials while introducing non-native functionality.