Nonionic surfactants usually do not show affinity to proteins and they work via competitive surface and interfacial processes in abinary mixture. However, we show in this work that Tween 80, a much bigger nonionic molecule than C12E5, with an oleyl chain, could initiate interaction possibly via the hydrophobic effect, evident from the surface tension plots. We propose to examine their surface co-adsorption processes by neutron reflection to gain direct structural evidence of the interaction, as this is a rather new observation from such systems. We request 3 days of Inter beam time to exploit the contrast variations by using deuterated Tween 80 in combination with 3 different water contrasts (weak signals under some contrast combinations). The proposed measurements will enable us to analyse the structures via the kinematic approach.