Electrostatic coalescer for coalescing a dispersed phase from a continuous phase in an emulsion

An electrostatic coalescer for coalescing of a dispersed phase from a continuous phase in an emulsion, the electrostatic coalescer comprising:

• at least one inlet for receiving the emulsion;
• at least one outlet for discharging the emulsion after coalescing the dispersed phase;
• at least one electrode disposed between the inlet and the outlet, wherein the electrode is configured to receive an AC voltage/current from a power source;
• and
• at least one article disposed between the inlet and the outlet, the article comprising a plurality of regions disposed on a surface in a predefined pattern, wherein a portion of the plurality of regions is substantially wetting with respect to the dispersed phase, a portion of the plurality of regions is substantially non-wetting with respect to the dispersed phase and the pattern comprises a plurality of inter-connected regions that are substantially wetting or non-wetting with respect to the dispersed phase.