The exploration of novel O/W filters having not only high permeation and rejection but also durable performance is a key driver of membrane material research. In this study, a glass fiber membrane (GF) was grafted with hyperbranched polyethyleneimine (HPEI) via a two-step process and used for O/W separation. The silanol group in the GF was reacted with epichlorohydrin followed by the reaction with the amine groups in the HPEI molecules. The obtained GF-g-HPEI membranes were characterized by FTIR, XPS, SEM and WCA measurements. The O/W separation performance was evaluated by dead-end filtration of a series of oil dispersion and emulsions. ATR-FTIR and XPS measurements indicated that HPEI was grafted on GF membrane surface successfully. The engineered GF membranes exhibit superwetting properties, outstanding permeability (1000 L/m(2)h at 10 cm gravity pressure) and quantitative oil rejection (>= 99.6%) for emulsified and dispersed oil. In addition, the modified membrane showed excellent thermal and chemical stability, compared with polymer-based membranes. All the above characteristics render the modified GF membrane cheap, effective and durable filters for O/W emulsion separation. (C) 2016 Elsevier B.V. All rights reserved.