Hierarchical Polysulfone Membrane for Emulsion Separation


This invention is ideal for separation of two immiscible liquids, like oil and water, for applications such as deep seep oil exploration, oil purification, oil spill cleanup.

Problem Addressed

Separation of oil and water mixtures is of great importance across a wide range of technologies and industries. Existing separation devices and methods are either environmentally unfriendly, extremely energy intensive, or incapable of performing the desired separations. For example, in deep soil oil extraction, when most of the water is separated using current methods, trace amounts of water still remain. These trace amounts of water in oil may cause problems for end users, process equipment, and machinery. Current separation techniques are therefore inefficient and incapable of performing the wide range of oil and water separations of interest. There is a need for more efficient devices and methods for separating oil and water mixtures. In particular, a need exists for separating trace amounts of water from oil and water mixtures.


This invention relates to articles and methods for separations. The hierarchical porous membrane suitable for use in oil/water separation processes is comprised of a polymer and is oleophilic and hydrophobic. It has a first layer with small pores and a second support layer that is substantially thicker than the first layer and has substantially larger pores than the first layer. The method of preparing this hierarchical porous membrane consists of combining a polymer, a pore former and a solvent to make a polymer solution, casting the polymer solution on a plate, following step, immersing the plate in a non-solvent to allow release of air bubbles and optionally, cutting the layer of the membrane  resulting from  the following step to undergo coagulation, thereby forming the hierarchical porous membrane.


  • Separate trace amounts of water
  • Easily alter properties of the membrane and control parameters critical to operation