Cussler, E. L.
Thirty years ago we knew nothing that membranes could not do. Of course, we knew nothing that they could do either. Now we know that membranes can purify water and separate air. Now we also know many tasks where membranes do not perform well. The details of these successes and failures make us more realistic, less willing to dream. In this talk, I want to dream again of what membranes might accomplish. In these dreams, I want to improve permeance or selectivity or molecular weight cut off by at least ten times. The opiates for my dreams are membranes made of block copolymers, which self-assemble to make monodisperse flakes or pores nanometers in size, which suggest routes to these dreams. Three specific cases will be discussed: barriers made of blocks of polyisoprene and polylactide, ultrafiltraion membranes made of blocks of polystyrene and polylactide, and ammonia selective membranes made of blocks of polycyclooctene and sulfonated polystyrene. These membranes can engender new dreams which fuel our search for new realities.