Sol-gel derived mesoporous 58S bioactive glass coatings on AZ31 magnesium alloy and in vitro degradation behavior

To improve the corrosion resistance and bioactivity, mesoporous 58S bioactive glass (58S MBG) coatings were prepared on AZ31 magnesium alloy via the sol-gel dip-coating method using Pluronic F127 (EO106PO70EO106) as pore-structure template. With the addition of F127, the glass transition temperature of 58S bioglass is significantly decreased to 385 °C, much lower than that of sample without F127 additives. Immersion tests in simulated body fluid (SBF) revealed that 58S MBG coatings could effectively provide corrosion protection for magnesium (Mg) alloys on account of the stable barrier properties. Meanwhile, apatite is observed on coating surface after 3 days immersion in SBF, suggesting that the mesoporous coatings could accelerate the apatite precipitation and thus improve the bioactivity of Mg alloy substrates. Furthermore, the formed apatite layer on sample surface also indirectly retards the biodegradation of Mg alloys to some extent.