Dispersibility and characterization of polyvinyl alcohol-coated magnetic nanoparticles in poly(glycerol sebacate) for biomedical applications

Magnetic nanoparticles (MNPs) often require surface modification to improve their dispersion in other materials for biomedical applications. Polyvinyl alcohol (PVA) is a low-cost, water-soluble polymer that has been reported to be biocompatible and biodegradable. In this study, we investigated the properties of MNPs coated with different weight percentages of PVA (i.e., 0%, 3%, 5%, 10%, 20%, and 30%) in a one-pot synthesis, to determine the ideal weight percentage of PVA needed to achieve the best dispersion of MNPs in a model polymer matrix such as poly(glycerol sebacate) (PGS). The results showed that PVA was successfully coated onto the surface of MNPs, and all the MNPs with 0 to 30% nominal PVA exhibited spherical shape and similar crystallinity and superparamagnetism. The average diameter of PVA-coated MNPs was 8 +/- 2 nm for 0, 3, 5, and 10% PVA-coated groups, but was slightly smaller for 20% and 30% groups with a respective diameter of 7 +/- 2 nm and 6 +/- 2 nm. The X-ray diffraction also confirmed that the particle sizes for 20% and 30% groups were slightly smaller than those of the other groups. When the MNPs were dispersed in the same PGS matrix and the weight percentages of PVA coating increased, less agglomerates of MNPs were observed and greater optical transmittance was achieved, indicating better dispersion. Overall, 30 wt.% of PVA coating used in MNP synthesis improved homogeneous dispersion of MNPs in a polymer matrix and reduced agglomeration. The effects of PVA content on the synthesized MNPs and the dispersion of MNPs reported in this study could be valuable for different applications when homogeneous dispersion of MNPs in a polymer matrix is desired.