Interaction of polyampholytic hydrogels based on partially hydrolyzed polyacrylamide with divalent metals

The sorption capacity of polyampholytic hydrogels prepared from partially hydrolyzed Polyacrylamide and ethylenediamine, 1,3-diaminopropane and 1,4-diaminobutane, with respect to divalent metal ions was studied. The amine numbers of the synthesized polyampholytic hydrogels were determined and amounted to 85-93 (mg of HCl) g(-1). The parameters of the polymer network and the mixing energies of the polyampholytic hydrogels and water were calculated (0.835-1.07 kJ mol(-1)), which correlate with the sorption capacity of the hydrogels. The hydrogel based on partially hydrolyzed polyacrylamide and 1,4-diaminobutane is characterized by the highest sorption capacity. The experimental data on equilibrium sorption are reliably described by the Langmuir model. The divalent metal ion forms coordination compounds with the polyampholytic hydrogels.

Automated summary

The sorption capacity of polyampholytic hydrogels prepared from partially hydrolyzed polyacrylamide and various diamines with respect to divalent metal ions was studied. The synthesized polyampholytic hydrogels exhibited amine numbers ranging from 85 to 93 mg of HCl per gram. The polymer network parameters and the mixing energies with water were calculated (0.835-1.07 kJ mol(-1)) and correlated with the sorption capacity of the hydrogels. The hydrogel based on partially hydrolyzed polyacrylamide and 1,4-diaminobutane showed the highest sorption capacity. The experimental data on equilibrium sorption were accurately described by the Langmuir model, indicating coordination compounds formation between divalent metal ions and polyampholytic hydrogels.