Study about how the metal cationic ions affect the properties of partially hydrolyzed hydrophobically modified polyacrylamide (HMHPAM) in aqueous solution

How the inorganic cations (Na+, Mg2+, Ca2+, Cr3+ and Fe3+) affect the properties of partially hydrolyzed hydrophobically modified polyacrylamide (HMHPAM) in aqueous solution was studied via molecular dynamics simulations, transmission electron microscopy, dynamic light scattering, Fourier transformation infrared spectroscopy, viscometer and conductivity measurements. The hydration and dehydration states of cations and the interaction force of the hydrated cations to the charged groups of polymer have been investigated by MD, which provided a fresh look into the interactions between cationic ions and HMHPAM. It was found that the water absorbing ability of cations was not always central to the degree of the effect on properties of HMHPAM. The coordination interaction and Coulomb interaction between multivalent cations and HMHPAM were found to be overwhelmingly important which accommodate remarkable effect on the property of the polymers in solution.