Poly(vinyl alcohol) Nanocomposites Reinforced with Bamboo Charcoal Nanoparticles: Mineralization Behavior and Characterization

Polyvinyl alcohol (PVA) demonstrates chemical stability and biocompatibility and is widely used in biomedical applications. The porous bamboo charcoal has excellent toxin absorptivity and has been used in blood purification. In this study, bamboo charcoal nanoparticles (BCNPs) were acquired with nano-grinding technology. The PVA and PVA/BCNP nanocomposite membranes were prepared and characterized by the tensile test, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray diffraction (XRD). Results showed that the tensile strength and elongation of the swollen PVA membranes containing 1% BCNPs (PB₁) were significantly greater than those of PVA and other PVA/BCNP composite membranes. In addition, the major absorption band of OH stretching in the IR spectra shifted from 3262 cm-¹ for PVA membrane containing 1% BCNP to 3244 cm-¹ for PVA membrane containing 20% BCNP. This blue shift might be attributed to the interaction between the PVA molecules and BCNPs. Moreover, the intensity of the XRD peaks in PVA was decreased with the increased BCNP content. The bioactivity of the nanocomposites was evaluated by immersion in the simulated body fluid (SBF) for seven days. The mineral deposition on PB₅ was significantly more than that on the other samples. The mineral was identified as hydroxyapatite (HA) by XRD. These data suggest that the bioactivity of the composite hydrogel membranes was associated with the surface distribution of hydrophilic/hydrophobic components. The PVA/BCNP composite hydrogels may have potential applications in alveolar bone regeneration.