“…The porous substrate does not hinder the filtrate from passing through, while at the same time it ensures mechanical robustness. Some examples include polymer supports (Sackmann et al, 2000), ceramics (Jayaraman et al, 1995), zeolites (Tavolaro et al, 2007), etc. This Chapter is dedicated exclusively to nanomembranes as freestanding or free-floating structures which are robust enough to ensure self-support.…”