Phosphorescent O2 sensors based on polyolefin fabric materials

Abstract

New phosphorescent oxygen sensors based on non-woven polypropylene membranes with grafted and ungrafted monofibres were created and evaluated. The two-component materials were fabricated by simple swelling of the polymeric fabric and partitioning of the phosphorescent dye molecules in an appropriate solvent system. The resulting sensors exhibited high brightness, optimal lifetime signals (22–30 μs at 21 kPa and 50–60 μs at 0 kPa O₂), linear Stern–Volmer plots, temperature dependence and low cross-sensitivity to humidity. Compared to state-of the-art O₂ sensors (PS coating on the microporous support), the new PP-based sensors performed well, showing good wettability and fast response time in liquid (5 min for grafted and 7 min for ungrafted PP vs. 32 min for the reference), mechanical stability without any additional support. Microscopic analysis of the PP fabric sensors by PLIM confirmed the homogenous dispersion of the dye throughout the membrane and uniformity of O₂ sensing properties.