Evaluation of mechanical properties and hemocompatibility of open cell iron foams with polyethylene glycol coating

Degradation Performance of Open-Cell Biomaterials from Phosphated Carbonyl Iron Powder with PEG Coating

“…Phosphating of iron powder caused a slight reduction of corrosion rate of Fe/P foam when compared to the bare Fe foam sample. In consistency with the results of our previous research [ 25 , 26 , 28 ], the higher corrosion rate was observed for samples with a polymer coating layer as compared to foams without PEG. The higher corrosion rate may be due to both the pH decrease caused by PEG dissolution and degradation and the iron complexation by PEG [ 28 ].…”

“…The densities of the Fe, Fe-PEG, Fe/P, and Fe/P-PEG foams were 0.72 ± 0.03 g·cm −3 , 0.95 ± 0.04 g·cm −3 , 0.81 ± 0.05 g·cm −3 , and 0.97 ± 0.03 g·cm −3 , respectively. The amounts of the polymer deposited onto the surface of the Fe and Fe/P foams, calculated from the differences in weight of foams before and after the coating layer deposition, were ~8.5 wt.% and ~8.2 wt.% for the Fe-PEG and Fe/P-PEG samples respectively, higher than the previous samples of 0.8–3 wt.% [ 25 , 26 , 28 ]. The porosities were 85%, 78%, 80%, and 76%, for Fe, Fe-PEG, Fe/P, and Fe/P-PEG foams, respectively.…”

“…The corrosion current densities and corrosion rates were in the sequence from high to low: Fe-PEG, Fe/P-PEG, Fe, Fe/P. Acceleration of the corrosion of coated samples can be attributed to local acidity in the vicinity of the surface of coated samples caused by the oxidative degradation of PEG [ 25 , 26 , 28 , 37 ]. A decrease in pH increases the solubility of the degradation products and thus hinders their precipitation and enables increased oxygen diffusion [ 18 , 25 ].…”

“…To prevent penetration of open pores, the foams were encased in Parafilm and sequentially weighted in air and water at room temperature. The Archimedes’ principle (DIN ISO3369) was used to determine the density from the following equation [ 28 , 29 ]: where m i , m PA , and m PW are the initial mass (g), mass of the foam encased in Parafilm determined in air (g), and mass of the foam encased in Parafilm determined in water (g), and ρ W and ρ P are the density (g cm −3 ) of water and Parafilm.…”

“…To prevent penetration of open pores, the foams were encased in Parafilm and sequentially weighted in air and water at room temperature. The Archimedes' principle (DIN ISO3369) was used to determine the density from the following equation [28,29]:…”