High density polyethylene (HDPE)/polyethylene-block-poly(ethylene glycol) (PE-b-PEG) blend porous membranes were prepared via thermally induced phase separation (TIPS) process using diphenyl ether (DPE) as diluent. The phase diagrams of HDPE/PE-b-PEG/DPE systems were determined by optical microscopy and differential scanning calorimetry (DSC). By varying the content of PE-b-PEG

the effects of PE-b-PEG copolymer on morphology and crystalline structure of membranes were studied by scanning electron microscopy (SEM) and wide angle X-ray diffraction (WAXD). The chemical compositions of whole membranes and surface layers were characterized by elementary analysis

Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS). Water contact angle

static protein adsorption and water flux experiments were used to evaluate the hydrophilicity

antifouling and water permeation properties of the membranes. It was found that the addition of PE-b-PEG increased the pore size of the obtained blend membranes. In the investigated range of PE-b-PEG content

the PEG blocks could not aggregate into obviously separated domains in membrane matrix. More importantly

PE-b-PEG could not only be retained stably in the membrane matrix during membrane formation

but also enrich at the membrane surface layer. Such stability and surface enrichment of PE-b-PEG endowed the blend membranes with improved hydrophilicity

protein absorption resistance and water permeation properties

which would be substantially beneficial to HDPE membranes for water treatment application.