Oil/water separation

A method of separating an oil and an aqueous medium from a mixture of the oil and the aqueous medium, the method comprising:

• A) contacting a first face of a composite membrane with the mixture of the oil and the aqueous medium to provide a separated aqueous medium at a second face of the composite membrane and a separated oil at the first face of the composite membrane;
• and
• B) recovering the separated aqueous medium from the second face of the composite membrane, or recovering the separated aqueous medium downstream from the second face of the composite membrane, and/or
• recovering the separated oil from the first face of the composite membrane, or recovering the separated oil downstream from the first face of the composite membrane,
• wherein:
• the composite membrane comprises a porous support membrane and a hydrated coating, wherein an external face of the hydrated coating corresponds to the first face of the composite membrane;
• the hydrated coating comprises a plurality of 2D phyllosilicate flakes and a plurality of cations associated with said 2D phyllosilicate flakes;
• and
• the hydrated coating is no less than 10 nm thick and no more than 60 nm thick.