Reinforcing epoxy with Ag-decorated flower-like TiO2nanoparticles: Structure and photocatalytic performance

The objective of this work was to synthesize silver (Ag) decorated flower-like (FL) titania (TiO2) nanoparticles and incorporate them into epoxy. The motivation was to increase the matrix-filler interlocking by FL morphology, so that mechanical durability of the surface could be preserved while photocatalytic capability was introduced to the polymer. FLTiO(2)nanoparticles were synthesized by solvothermal reaction at 180 degrees C, for 4 h. Ag-decoration was performed by a simple solution-mixing approach using silver nitrate. 4 wt.% reinforced FLTiO2/epoxy composites were prepared w/o Ag-decoration. X-ray diffraction (XRD), scanning/transmission electron microscopy (SEM, TEM), gas adsorption (N-2), Fourier-transform (FT) infrared (IR) and UV-visible spectroscopies were used to characterize the phases, morphology, surface, chemical and optical structure of the nanoparticles. Nanoparticles were composed of rutile (71%) and anatase (29%) phases and exhibited a mesoporous structure with an indirect band gap of 2.90 eV. Analysis of the nanocomposites indicated that FLTiO(2)nanoparticles formed Ti-O-C linkages with epoxy at the interface and enhanced mechanical/chemical interlocking resulted in 13-fold increase in microhardness. Water sorption (WS) was not significantly affected by FLTiO(2)reinforcement, but Ag-decoration increased the WS. FLTiO2/epoxy nanocomposites exhibited photocatalytic performance up to 48 h, w/o Ag-decoration. Ag-decoration enhanced the degradation rate. Each nanocomposite was reusable and was still photo-active after 3 cycles. In the overall, considering the well-known antimicrobial behavior of Ag, the synergic effect of Ag with FLTiO(2)in epoxy can provide durable alternatives which require microbe/pollutant resistance in public environments.