LAUSR

Abstract A new economic method of modifying chitosan based on direct condensation reaction between chitosan and phenolic acids “Gallic or Caffeic acids” to produce new condensation adducts RI and RII. The new adducts structure and morphology were confirmed by physical and chemical tools such as FTIR, TGA, SEM, elemental analysis, water regain, dissociation in acidic medium, and point of zero charge. The new adducts were evaluated as silver ions adsorbents. The new adducts showed efficient removal of toxic silver ions from the aqueous medium with removal efficiency reached 100% and 92.66% for RI and RII respectively. Factors affecting on adsorption process as well as Kinetics, equilibrium, and thermal properties of adsorption were studied using conventional equations. Both adducts showed good re-use ability lasted for three cycles.