Laminated graphene oxide (GO) has promising use as a membrane because of its high permeance, chemical and mechanical stability, as well as the molecular sieving effect of its interlayers. However, the hydrophilic surface of GO, which is highly decorated with oxygen groups, easily induces delamination of stacked GO films in aqueous media, thereby limiting the practical application. To stabilize GO films in aqueous media, we functionalized a polymer support with branched polyethylene-imine (BPEI). BPEI adsorbed intercalated into the stacked GO sheets via diffusion during filtration. The GO/BPEI membrane obtained exhibits high stability during sonication (>1 h duration, 40 kHz frequency) in water within a broad pH range (2-12). In contrast, the GO film spontaneously delaminated upon sonication. Furthermore, BPEI treatment did not affect the filtration performance of the GO film, as evidenced by the high rejection rates (>90%) for the dye molecules methylene blue, rose bengal, and brilliant blue and by their permeation rates of ca. 124, 34.8, 12.2, and 5.1%, respectively, relative to those of a typical GO membrane.
Bibliographical noteFunding Information:
This study was supported by the Climate Change Research Hub of KAIST (Grant N01150139) and the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2015R1A6A3A04057367), as well as by the Leading Foreign Research Institute Recruitment Program through the NRF funded by the Ministry of Education, Science and Technology (NRF-2015K1A4A3047100). PAL provided technical support for the small-angle X-ray scattering (3C1 SAXS) beamline used in our study.
All Science Journal Classification (ASJC) codes
- Materials Science(all)