Composite membranes, methods of making same, and applications of same

A method of fabricating a composite membrane, comprising:

• forming one or more first-type polymer solutions from one or more first-type polymers and one or more second-type polymer solutions from one or more second-type polymers, respectively, wherein each of the one or more first-type polymers comprises a charged polymer and each of the one or more second-type polymers comprises a uncharged (or minimally charged) polymer;
• electrospinning, separately and simultaneously, the one or more first-type polymer solutions and the one or more second-type polymer solutions to form a dual or multi fiber mat of one or more first-type polymer fibers and one or more second-type polymer fibers;
• and
• processing the dual or multi fiber mat by softening and flowing at least one of the one or more first-type polymer fibers to fill in the void space between the one or more second-types polymer fibers, or by softening and flowing at least one of the one or more second-type polymer fibers to fill in the void space between the one or more first-types polymer fibers, so as to form the composite membrane.

A composite membrane, comprising:

• a fiber network, formed from a dual or multi fiber mat of one or more first-type polymer fibers and one or more second-type polymer fibers;
• and
• a polymer matrix encompassing the fiber network, wherein the polymer matrix is formed by softening and flowing at least one of the one or more of the first-type polymer fibers of the dual or multi fiber mat to fill in the void space between the one or more second-type polymer fibers of the dual or multi fiber mat, or by softening and flowing at least one of the one or more of the second-type polymer fibers of the dual or multi fiber mat to fill in the void space between the one or more first-type polymer fibers of the dual or multi fiber mat,
• wherein the one or more first-type polymer fibers comprise charged polymer fibers or charged polymer precursor fibers, and the one or more second-type polymer fibers comprise uncharged polymer fibers.