“…[16][17][18] The solutionbased methods used to obtain TiO 2 nanoparticles include hydrothermal, solvothermal, hydrolytic and non-hydrolytic sol-gel syntheses. 16,19,20 The functional TiO 2 layers are usually obtained through various coating and printing methods such as dip coating, 21,22 spin coating, 23,24 drop casting, 25,26 screen printing, [27][28][29] inkjet printing, 14,15,30 3D-printing, 31 and various contact printing techniques (gravure, offset, flexography, etc.). [32][33][34] All of the coating and printing deposition methods require the rheological adjustment of a functional ink to meet the specific technological conditions and to control the thickness of the depositing layer.…”