Effect of pigment concentration and particle size of TiO2 support on performance of chemochromic hydrogen tape sensor

A chemochromic hydrogen tape sensor has been developed to detect hydrogen leaks using titania (TiO2) supported palladium oxide (PdO) pigments encapsulated within a silicone matrix. This study has been carried out to investigate the effects of pigment (PdO-TiO2) concentration and particle size of TiO2 support on detection performance in terms of color contrast of a chemochromic hydrogen tape sensor. The irreversible hydrogen tape sensors were tested with different concentration from 0.2 wt% to 10.0 wt%. Several pigments were synthesized using three different TiO2 support with particle sizes ranging from 100 nm to 5 μm. The experimental results exhibit that the color of the pigment with 0.2 wt% shows distinctive color change in minimum and the optimal pigment concentration for silicone matrix type irreversible tape sensor is 3.0 wt%. In addition, TEM analysis revealed that the PdO particles become larger and agglomerated as increasing the particle size of TiO2 support. The pigment with Aldrich TiO2 particle size ≤5 μm has a good performance than smaller one.