Porous Biocoatings Based on Diatomite with Incorporated ZrO2 Particles for Biodegradable Magnesium Implants

Abstract

In the present work, the surface of a biodegradable Mg alloy was modified to create porous diatomite biocoatings using the method of micro-arc oxidation. The coatings were applied at process voltages in the range of 350–500 V. We have studied the influence of the addition of ZrO2 microparticles on the structure and properties of diatomite-based protective coatings for Mg implants. The structure and properties of the resulting coatings were examined using a number of research methods. It was found that the coatings have a porous structure and contain ZrO2 particles. The coatings were mostly characterized by pores less than 1 μm in size. However, as the voltage of the MAO process increases, the number of larger pores (5–10 μm in size) also increases. However, the porosity of the coatings varied insignificantly and amounted to 5 ± 1%. It has been revealed that the incorporation of ZrO2 particles substantially affects the properties of diatomite-based coatings. The adhesive strength of the coatings has increased by approximately 30%, and the corrosion resistance has increased by two orders of magnitude compared to the coatings without zirconia particles.

Functionalizing Diatomite-Based Micro-Arc Coatings for Orthopedic Implants: Influence of TiO₂ Addition

“…The amount of dissolution products on the surface of the alloy increases with an increase in the duration of incubation. Similar patterns were observed and described in previous studies [44,51].…”

“…Figure 2 displays the thickness and roughness of the coatings in relation to MAO process voltage. The thickness of deposited coatings increases exponentially, which correlates well with our previous studies related to diatomite-based coatings [44,51]. The surface roughness ranges from 2.5 to 5 µm, with a sharp increase at 450 V. This is due to the more intense course of the micro-arc oxidation process at higher voltages, which leads to a greater number of micro-arc plasma discharges on the substrate surface.…”

Functionalizing Diatomite-Based Micro-Arc Coatings for Orthopedic Implants: Influence of TiO2 Addition

“…Figure 2 displays the thickness and roughness of the coatings in relation to the MAO process voltage. The thickness of deposited coatings increases exponentially, which correlates well with our previous studies related to diatomite-based coatings [48,55]. The surface roughness ranges from 2.5 to 5.0 µm, with a sharp increase at 450 V. This is due to the more intense course of the micro-arc oxidation process at higher voltages, which leads to a greater number of micro-arc plasma discharges on the substrate surface.…”

Biomimetic Diatom Biosilica and Its Potential for Biomedical Applications and Prospects: A Review

“…Increasing the voltage in the MAO process increased the number of relatively larger pores (5-10 µm in size). Incorporating ZrO 2 particles significantly affected the properties of DE-based coatings, with adhesive strength increasing by approximately 30% and corrosion resistance increasing by two orders of magnitude compared to coatings without zirconia particles [70].…”