porous membranes

microfiltration, ultrafiltration

-membranes of this class induce separation by disciminating between particle size.

-High selectivities can be obtained when the solute size or particle size is large relative the pore size in the membrane.

-For the porous membranes the dimension of pore mainly determines the separation characteristics.

-the type of membrane material is of crucial importance for chemical, thermal and mechanical stability but not for flux and rejection.

-syringe filters belongs to the microfiltration.

-Membranes from this class are capable of separating molecules of approximately the same size from each other.

-Separation takes place through differences in solubility and /or differences in diffusivity.

-This means that the intrinsic properties of polymeric material determine the extent of selectivity and permeability.