Injection of carbon dioxide (CO2) into finely bedded reservoirs leads to enhanced contact area with water and hence enhanced dissolution rates. The dissolution of free-phase CO2, and hence the rates at which it travels within the reservoir, transitions from advection to diffusion dominated as the contact area with water increases. For injection into the heterogeneous Salt Creek reservoir in Wyoming, nearly 10% of the injected CO2 is predicted to dissolve in one year suggesting that dissolution in heterogeneous formations can play a
The motion of ice sheets to the ocean depends sensitively on the amount of water present beneath the ice, and particularly at the grounding line, where the ice touches down onto the bedrock beneath. This study explore how ocean water can be pumped into the region underneath ice sheets as the ocean tides go up and down and hence in and out of the subglacial cavity. We show that tides rush in but are slow to flow out, much like waves washing up on the beach, and this asymmetry can act as a nonlinear filter that may explain observations of tidal
The investigation of buried interfaces, such as the mineral/aqueous solution interface, is experimentally challenging. Neutron reflectometry is a well-established and non-invasive technique that allows behaviour at these interfaces to be measured, and a technique has been developed within the group to allow the surface of the mineral muscovite mica to be measured. This surface shows atomic flatness due to perfect cleavage along the basal plane, and is negatively charged in solution.
We show how droplets which comprise two solvents of different volatility can display an instability during drying. This can drive suspended solutes to the edge of the droplets and create a non-homogeneous final film.
We make micron sized water core droplets surrounded by a polymer shell and then place a silver layer around the entire droplet to seal it. The capsules can be used to deliver pharmaceuticals and other small molecules to desired locations.
Buried interfaces, pertinent to realistic environments such as those found in a car engine, are notoriously difficult to investigate due to the challenges of accessing information concerning the interface itself without being swamped by the much greater signal from the bulk materials; here, we describe the combination of a suite of sophisticated surface study techniques to characterise small molecules adsorbing at key metal surfaces from an oil phase.
Understanding the structure and behaviour of proteins adsorbing at key biomaterial surfaces is both challenging but also critical to designing implants that interact favourably with the body. Here, we report the first use of the powerful surface analysis technique neutron reflectometry to characterise a stainless steel surface and the adsorption of key proteins found in the blood plasma thereupon.
Figure illustrating the very thin mica sheet on the silicon block support. The Data shows the distinctive ‘double critical angle’ indicative of the mica/D2O interface (the two ‘steps’ at low Q) and the changes on adsorbing a layer of AOT at the mica surface, clearly evidence at high Q. using data such as this we can identify and structurally characterise the layers at the mica surface.
Migration of CO2 through storage reservoirs can be monitored using time lapse seismic reflection surveys. At the Sleipner Field, injected CO2 is distributed throughout nine layers within the reservoir. These layers are too thin to be seismically resolvable by direct measurement of the separation between reflections from the top and bottom of each layer. Here we develop and apply an inverse method for measuring thickness changes of the shallowest layer.