Porous poly(vinylidene fluoride) (PVDF) membranes for dehumidification were prepared from a PVDF/dimethylformamide/water system by phase inversion with poly(ethylene glycol) (PEG) as an additive at
various concentrations (1.2, 1.8, and 2.4%) and with various molecular weights (1000, 2000, and 6000). The surface
morphologies of the resultant membranes were characterized with scanning electron microscopy and atomic force
microscopy, and the pore diameter, porosity, and pore size distribution of the membranes were also determined
by a gas-sorption method. The influence of the concentration and molecular weight of PEG on water-vapor transport
through the membranes was evaluated. The moisturetransport property of the membranes was improved significantly
with increases in the concentration and molecular weight of PEG, and a membrane with good moisture permeability
was obtained with 2.4% PEG-6000 as an additive