The research interests of the Mills group are wide and varied including: dye and semiconductor photochemistry, redox catalysis (in particular, oxygen catalysis), solar energy conversion (in particular artificial photosynthesis) and colour and fluorescence based indicators and smart inks and plastic films.

Open Access Paper – Extruded polymer films pigmented with a heterogeneous ion-pair based lumophore for O2 sensing

A novel approach to polymeric Ru(II)-diimine luminescent O­sensors is described. The Ru(II)-diimine, tris (4,7-diphenyl-1,10-phenanthroline) ruthenium (II) dichloride ([Ru(dpp)3]2+), is first ion-paired to the surface of heterogeneous TiO2 particles, rendered negatively charged due to the alkali nature of the aqueous solution, to produce an O2 sensitive pigment with a strikingly high oxygen sensitivity (i.e. PO2 (S=1/2) = 0.002 atm, where PO2 (S=1/2) is defined as the amount of oxygen required to reduce the initial, oxygen free luminescence by 50%), and a rapid response to oxygen. The pigment is extruded in low density polyethylene (LDPE) to produce a thin (60 µm), flexible, O2 sensing plastic film, with an O2 sensitivity (PO2 (S=1/2) = 0.84 atm) comparable to the more traditional homogeneous lumophore ion-pair based O2 sensor ink films reported in the literature.

this is an open access article and can be downloaded free of charge from:!divAbstract