Nardi, TommasoRtimi, SamiPulgarin, CesarLeterrier, Yves2016-02-162016-02-162016-02-16201510.1039/c5ra19298fhttps://infoscience.epfl.ch/handle/20.500.14299/123616WOS:000366865900092Functionally graded epoxy composites with various concentration profiles of Fe3O4@TiO2 core-shell nanoparticles (NPs) were synthetized and characterized, with focus on their antibacterial properties. The NPs consisted of rutile, anatase, magnetite and hematite. Graded composites were produced starting with homogeneous 2 vol% to 12 vol% NPs suspensions using a magnetophorese process, leading to an enrichment of TiO2 at the surface of the composite up to 16 vol% from an initial 4 vol%. Homogeneous composites were also produced as references. Graded composites with an initial 4 vol% of NPs inactivated E. coli bacteria in less than 2 hours under simulated solar light (50 mW cm(-2)), significantly faster than their homogeneous analogues. During bacterial inactivation the pH decreased from 6.8 to 5.0. Repetitive E. coli inactivation tests on these 4 vol% graded composites were stable up to 8 cycles and 5 min contact between the bacteria and the sample surface was enough to guarantee an adequate bacterial adhesion.text::journal::journal article::research article