fdca 2,5-FURANDICARBOXYLIC ACID Furane-alpha Preparation of polyethyleneimine-changed chitosan/Ce-UIO-66 composite hydrogel for the adsorption of methyl orange.In this work, a polyethyleneimine-changed chitosan/Ce-UIO-66 composite hydrogel (PEI-CS/Ce-UIO-66) was cooked using the ex-situ blend method. The synthesized composite hydrogel was characterised by SEM, EDS, XRD, FTIR, BET, XPS, and