AN OXYGEN-RELEASING DEVICE - REVERSIBLE OXYGEN RELEASE FROM A COBALT CHELATE CARBON COMPOSITE IN RESPONSE TO AN APPLIED VOLTAGE

A disk (e.g. diameter 2 cm x 2 mm) was made of [N,N'-bis(salicylidene) ethylenediamine] cobalt [Co(salen)] and carbon powder. The composite d isk selectively absorbed oxygen from air, e.g. 22 cm(3) oxygen per gra m of composite at room temperature, which is almost stoichiometrically ascribed to 2: 1 cobalt-dioxygen adduct formation. The adduct formati on was an exothermic reaction, and the absorbed oxygen was released ab ove 80 degrees C. The application of 6 V to the disk sandwiched betwee n platinum meshes induced a temperature elevation in the disk, which q uickly released the absorbed oxygen. Under ambient conditions, the oxy gen-releasing and -absorbing processes could be established within a f ew min and a 30 min interval, respectively, for the composite disk con taining the 3-ethoxy derivative of Co(salen), while the oxygen absorpt ion took several hours for the Co(salen) disk.