The aim is to use Neutron Reflectivity (NR) to gain essential information on adsorption properties of practical fluorotelomer surfactants used in fire-fighting foam formulations (Figure 1). NR is needed to further understanding how molecular packing in air-water interfacial films influences surface tensions. These surfactants have already been studied individually by SANS and this provided necessary information on the self-assembled structures in solution. This is the first stage in a new 3-year program, including NR, so that F-carbon surfactants can be replaced by more environmentally-responsive low-F or hydrocarbon analogues. A sister proposal has been submitted this round to study aggregation of these surfactants as mixed systems by SANS (“Micellization in mixtures of surfactants used in fire-fighting foams”). Chris Hill is a 2nd year PhD student fully funded by Angus Fire.