Chemical engineering science vol:57 issue:13 pages:2511-2518
The solvent flux and rejection of 2, 2'-methylenebis-(6-tert-butyl-4-methyl phenol) was studied in water, ethanol and n-hexane for four solvent-stable polymeric nanofiltration membranes (N30F, NF-PES-10, MPF-44 and MPF-50). Solvent fluxes were analysed with the Machado model to determine hydrophobicity/hydrophilicity of the membranes. The results are consistent with N30F, NF-PES-10 and MPF-44 being hydrophilic membranes, and MPF-50 being a hydrophobic membrane. The solvent flux for MPF 50 increases with decreasing polarity of the solvent: for n-hexane, a flux as high as 1600 1/m(2) h was obtained at a 20 bar transmembrane pressure. Much lower fluxes were found with ethanol; water fluxes were almost zero. For the other three membranes, the flux decreases in the order water > ethanol > n-hexane, i.e. with decreasing polarity.