FT-IR characterization of antimicrobial hybrid materials through sol-gel synthesis

Silica/polycaprolactone and titania/polycaprolactone hybrid organic/inorganic amorphous composites were prepared via a sol-gel method starting from a multi-element solution containing tetramethyl orthosilicate (TMOS) or titanium butoxide (TBT), polycaprolactone (PCL), water and methylethylketone (MEK). The molecular structure of the crosslinked network was based on the presence of the hydrogen bonds between organic/inorganic elements as confirmed by Fourier Transform Infra-Red (FT-IR) analysis. In particular, the structure of crosslinked network was realized by hydrogen bonds between the X-OH (X = Si or Ti) group (H donator) in the sol-gel intermediate species and ester groups (H-acceptors) in the repeating units of the polymer. The morphology of the hybrid materials; pore size distribution, elemental homogeneity and surface features, was studied by scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) and by atomic force microscopy (AFM). The bioactivity of the synthesized hybrid materials was confirmed by observing the formation of a layer of hydroxyapatite (HAP) on the surface of the samples soaked in a simulated body fluid. The antimicrobial behavior of synthetized hybrids was also assessed against Escherichia coli bacteria. In conclusion, the prepared hybrid materials are proposed for use as future bone implants.