Colour changing pigments detect minute hydrogen leaks

US Scientists from the Florida Solar Energy Centre have developed a 'smart paint' that changes colour in the presence of hydrogen, allowing visible detection of minute leaks.

With many predicting a future 'hydrogen economy', simple and cheap detection of the gas will be vital. The technology could prove invaluable for use on hydrogen fuel cell powered vehicles, at hydrogen fuel stations, as well as on the infrastructure transporting the gas. Hydrogen is an odourless and colourless substance, so a simple leak detection system could do much to reassure future developers, local authorities and users. The technology is being applied at the Kennedy Space Centre where it is detecting leaks in the joins of pipe work (pictured). The darker area shows where the gas is escaping. The paint uses an inexpensive metal oxide based powder that can also be deposited onto tapes that adheres to pipe and flange joints. The paint undergoes either an irreversible or reversible change. The irreversible formulations are based on titanium oxide supported palladium oxide pigments encapsulated within a silicone matrix. The reversible formulations are based on polyoxometalates of tungsten and molybdenum, doped with small amounts of platinum to catalyse the colouration bleaching reaction.