An interfacial composite structure as well as a method of making an interfacial composite structure are disclosed. The interfacial composite structure includes a support structure; and an interfacial membrane. The interfacial membrane is formed by a first organic solution and a second organic solution. The first organic solution includes a first reactant and the second organic solution includes a second reactant. The support structure is in contact with at least one of the organic solutions and the interfacial membrane includes a crosslinked polymer formed by the first reactant and the second reactant.