Coating of metallic implant surfaces with synthetic hydrogel polymers by electropolymerization method to increase biocompatibility

The aim of this study is to coat 316L stainless steel which is used as an implant material with bio-compatible poly (HEMA-GDMA) by electropolymerization method and to develop the functionality and the bio-compatibility of the coatings. In the electropolymerization cell; (NH4)2S2O8 and H2SO4 (sulphuric acid) were chosen as the initiators, while 316L stainless steel, graphite electrode and saturated calomel electrode (SCE) were chosen as working electrode, counter electrode, and reference electrode, respectively. Also Na2SO4 was used for increasing the conductivity of the solution. In order to increase the adhesion of coatings, surface preparation processes were applied to the metal. Thickness, homogenity and adehesion properties of the coating depend on the type of initiators, cross-linker concentration and applied voltage. First optimum coating conditions were determined in terms of applied potential, initiators, monomer and cross-linker concentrations. These parameters were tried to be optimized and coatings with different thickness and morphologies were obtained. Surface morphologies of the coatings were examined by optical microscope and scanning electron microscope (SEM), the chemical characterizations were done using energy dispersive spectroscopy (EDS) and FT-IR. Surface thickness and roughness of the coatings were obtained by the surface profilometer device.