Enhancement of the physical/mechanical properties of an epoxy composite by addition of aluminum nanoparticles through modification with cerium oxides and functionalization by SiO2-NH2 thin films

The surface of aluminum (Al) nanoparticles (80-100 nm) was modified by a thin film composed of cerium oxides (i.e CeO2) and then functionalized by 3-aminopropyltriethoxysilane (APTES) to improve the physical/mechanical properties of an epoxy/polyamide coating. The surface chemistry of nanoparticles was studied by means of X-ray photoelectron spectroscopy (7iPS), Fourier transform infrared spectroscopy (FT-IR) and thermal gravimetric analysis (TGA) analysis. The physical/mechanical properties of the nanocomposites were evaluated by dynamic mechanical thermal (DMTA) analysis and tensile test. The fracture surface morphology was studied by scanning electron microscopy (SEM). It was found that compared to the untreated nanoparticles, the nano particles functionalized with SiO2 film showed higher compatibility and more uniformly dispersed in the epoxy matrix. Results of tensile test showed that addition of 2 wt.% Al-SiO2 and Al-CeO2-SiO2 nanoparticles to the epoxy coating remarkably enhanced the energy and elongation at break compared to the neat epoxy and the one reinforced with neat Al particles. The increase of glass transition temperature (T-g), loss peak height, storage modulus at glassy and rubbery plateau zone was the most significant in the case of coatings modified with Al-Ce-Si particles.