Titanium dioxide-coated expanded polymer sheet having photocatalytic activity, container and packaging for foodstuffs obtained from such polymer sheet

摘要

A method is described for the production of a polymer leaf of expanded polymeric material coated with titanium dioxide (TiO₂) on at least one of the surfaces thereof, the method comprising the steps of:a) mixing an organic TiO₂ precursor with an acidic aqueous solution;b) hydrolysing the organic TiO₂ precursor in said acidic solution to yield a TiO₂ sol or suspension in which the TiO₂ is in a substantially crystalline and photocatalytically active form with particles of nanometric and/or sub-nanometric dimensions,c) optionally converting the TiO₂ sol into a TiO₂ gel, the TiO₂ gel subsequently being mixed with an alcohol;d) applying the TiO₂ sol or suspension, or the TiO₂ gel mixed with alcohol, onto a leaf of expanded polymeric material in such a manner as to coat at least one surface of the polymer leaf with a TiO₂ film in which the TiO₂ is substantially in a photocatalytically active crystalline form with particles of nanometric and/or sub-nanometric dimensions.;Methods are also described for producing containers and packages for foodstuffs starting from polymer leafs coated with TiO2 obtained in the above manner.