The effect of dopamine modified titanium dioxide nanoparticles on the performance of Poly (vinyl alcohol)/titanium dioxide composites

In order to improve the dispersion of nanoparticles (NPs) and enhance the interfacial interactions between NPs and Poly (vinyl alcohol) (PVA) matrix, the surface of titanium dioxide (TiO2) was modified by green and biocompatible dopamine (DA). PVA composites containing TiO2 or modified TiO2 (DA-TiO2) were fabricated through simple one-step method. The as-prepared composites were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), tensile experiments and thermogravimetric analysis (TGA). The TEM images demonstrated that DA-TiO2 NPs were dispersed well in the PVA matrix, which may originate from the hydrogen bonding and covalent bond formed between PVA and DA-TiO2 NPs. The tensile experiments exhibited significant improvement for the mechanical properties of PVA composites with proper amount of DA-TiO2 NPs. Especially, the PVA composites with 1 wt% DA-TiO2 NPs displayed the desired consequences in terms of tensile strength and toughness, compared to the pure PVA, which were increased by 47.9% and 145.2%, respectively. The TGA curves showed that DA-TiO2 NPs enhanced the thermal stability of PVA. Additionally, PVA/DA-TiO2 composite showed relatively good optical transparency and water resistance.