Síntese e caracterização de materiais fotocrômicos híbridos impressos em 3D

This research aimed to produce transparent and photochromic polymer-WO3 hybrid parts by FDM 3D printing (layer-by-layer Fused Deposition Modelling) for optical applications. A laboratory investigation was conducted employing the polyol method for the synthesis of sub-stoichiometric tungsten oxide WO3-x, which was subsequently subjected oxidized by potassium dichromate K2Cr2O7. The photochromism of the synthesized WO3 was confirmed after irradiation under UV lamp. Experiments with several polymers showed that PMMA is the most suitable polymer for composing the matrix of the hybrid material. PMMA-WO3 hybrid blocks were produced by a solution route and characterized by UV-vis-NIR spectrophotometry, showing its photochromism. As the required diameter of filaments for 3D printing is 1.75 mm, fibering has been found ineffective for the production of PMMA-WO3 adequate hybrid filaments. Extrusion was chosen as the method for obtaining filaments for 3D printing, but due to technical problems with the extruder, the diameters of the filaments obtained were not close enough to 1.75 mm to be printed directly by FDM.