Eco-friendly polymer succinate capping on silver nano-particles for enhanced stability: a UV-Vis and electrochemical particle impact study

A facile green method is used to synthesize silver nanoparticles (Ag Nps) in one minute. The colloidal stability of two types of Ag Nps (namely, hydroxypropylcellulose-succinate (HPC-Suc) capped silver nanoparticles (Ag Nps@suc) and citrate-capped silver nanoparticles (Ag Nps@cit)) is investigated using UV-Vis spectrometry and electrochemical particle impacts “nano-impacts” measurements. Ag Nps@suc were newly synthesized by simply mixing aqueous solutions of HPC-Suc and silver nitrate and exposure to sunlight. The growth of Ag Nps was controlled by adjusting the exposure time to sun light. Local surface plasmon resonance (LSPR) study was conducted using UV-Vis spectrophotometer. The surface morphology, size, elemental analysis and composition of Ag NPs@suc was determined by SEM-EDX, while ATR-FTIR was used to assess any type of chemical reactions between the precursors. For stability and size distribution measurements zeta-potential (ZP), dynamic light scattering (DSL) and anodic particle coulometry (APC) were performed. The as-prepared Ag Nps@suc exhibited a narrow size distribution with an average diameter of 20 nm. Nps sizing using particles electrochemical impacts method is consistent with SEM and DLS techniques. The results show that Ag Nps@cit are prone to relatively rapid clustering upon addition of electrolyte (100 mM K2SO4). On the other hand, Ag Nps@suc exhibit excellent stability with only ~ 9% decay in absorbance over 24 h even at high electrolyte concentration. Using KCl, KBr and NaCl electrolytes, the stability of the synthesized Ag Nps@suc also compares favorably to Ag Nps@cit.