New and conventional pore size tests in virus-removing membranes

► Monodispersions of Au3+ Ag+ nanoparticles help evaluate the UF membrane pore size distribution. ► The absolute pore size d100 is determined by the particle retained with 100% efficiency. ► The virus retention can be predicted directly or with models fed with d100. ► The absolute pore size in majority of polymer UF membranes is within 40-50 nm diapason.