An understanding of the adsorption of polymers on clay minerals is important in secondary oil recovery where polymers are used as clay swelling inhibitors. Here we propose to characterise the adsorption of sodium polyacrylate at the water mica interface using neutron reflection. Polymer adsorption on mica has been studied numerous times using other techniques but never before using neutron reflection which can provide unique molecular level detail. Here, we will determine the evolution of the adsorbed layer structure with polymer concentration and determine the key role that calcium ions have on polymer adsorption and layer structure.