Superhydrophobic and oleophobic luminescent composite materials for oxygen sensing in fuel-laden atmospheres

Abstract

Accurate measurement and monitoring of oxygen concentration in fuel-laden atmospheres is crucial for reducing the risk of fire and explosion. Oxygen sensors based on luminescence quenching are suitable for such applications. This study explored a luminescent composite material for use as an oxygen sensor. The composite was prepared by dispersing a platinum(II)-5,10,15,20-tetra-(2,3,4,5,6-pentafluorophenyl)porphyrin oxygen-sensitive probe in a polydimethylsiloxane film supported on a silicon wafer with a nano-structured porous silica intermediate layer. The composite was modified by vapor deposition of trichloro(1H,1H,2H,2H-perfluorooctyl)silane. The modified composite demonstrated superhydrophobic and oleophobic properties with contact angles measuring 165° towards water and >150° towards solutions with surface tensions exceeding 26.8 mN m⁻¹. It displayed a linear Stern–Volmer relation within an oxygen concentration range of 0–30%, featuring a relatively high Stern–Volmer constant of 0.120 h Pa⁻¹. The superhydrophobic and oleophobic composite material exhibited notable stability, with its Stern–Volmer constant remaining almost unchanged after exposure to a fuel-laden atmosphere for 12 hours. It is concluded that the composite material developed in the present study is promising for use as an oxygen sensor in environments with fuel vapors.