Perfluorocarbon-free membranes for membrane distillation

A membrane distillation method, comprising:

• providing a perfluorocarbon-free membrane, the perfluorocarbon-free membrane comprising
• a non-perfluorocarbon material having a first side and a second side opposite of the first side, the non-perfluorocarbon material forming a hydrophilic layer;
• and
• a plurality of pores, each having an inlet and outlet and each passing through the non-perfluorocarbon material so that each pore provides fluidic communication between the first and second sides of the non-perfluorocarbon material,
• wherein a portion of the non-perfluorocarbon material extends over the inlet and outlet of each the plurality of pores so that a cross-sectional area (Ci/o) of the inlets and outlets in a direction of the extension of the non-perfluorocarbon material is smaller than a cross-sectional area (Cp) of the respective pore in the direction of the extension of the non-perfluorocarbon material, wherein the perfluorocarbon-free membrane does not include a hydrophobic perfluorocarbon coating, and
• wherein the cross-sectional area (Ci/o) of the inlets and outlets and the cross-sectional area (Cp) of the respective pore extend within the hydrophilic layer,
• arranging the perfluorocarbon-free membrane so that the first side of the perfluorocarbon-free membrane is exposed to salinated water and the second side of the perfluorocarbon-free membrane is exposed to non-salinated water, wherein the salinated water is warmer than the non-salinated water,
• wherein air is entrapped in each of the plurality of pores so that water vapor passes through each of the plurality of pores from the first side to the second side of the perfluorocarbon-free membrane and the salinated water does not pass through the plurality of pores from the first side to the second side of the perfluorocarbon-free membrane.

A method for forming a perfluorocarbon-free membrane, the method comprising:

• providing first and second sheets of non-perfluorocarbon material, each having a first side and a second side that is opposite the first side;
• forming a plurality of cavities in the first and second sheets of non-perfluorocarbon material, each of the plurality of cavities having a bottom on the second side of the respective sheet of the non-perfluorocarbon material;
• forming a passageway through the bottom of each of the plurality of cavities and through the second side;
• and
• joining the first side of the first sheet non-perfluorocarbon material with the first side of the second sheet of non-perfluorocarbon material to form the perfluorocarbon- free membrane,
• wherein the perfluorocarbon-free membrane does not include a hydrophobic perfluorocarbon coating.