Modification of poly acrylic acid using calix[4]arene derivative for the adsorption of toxic heavy metals

Poly acrylic acid (PAA) was grafted with p ‐ t ‐butyl calix[4]arene diamine (distal cone) (2) to adsorb toxic heavy metal and alkali metal cations. The grafting method includes the amidation reaction of PAA with calixarene diamine derivative 2 which was carried out in N,N ‐dimethylformamide (DMF) and N –methyl‐2‐pyrrolidone (NMP) as solvents. The modified PAAs (PAA‐C1 and PAA‐C2) were characterized by FTIR, 1 H‐NMR, thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). PAA‐C1 and PAA‐C2 were used to evaluate the sorption properties of some toxic heavy metal cations (Co 2+ , Cu 2+ , Cd 2+ , Hg 2+ ), alkali metal cations (Na + , K + , Cs + ), and Ag + . Results showed that the modified PAAs were good sorbents for heavy metal and alkali metal cations. The main goal of this project is to design hydrophobically modified PAA that is suitable for ion selective membranes and chemical sensor devices for adsorption of toxic heavy metals.