Abstract
Radiation grafting of polyethyleneimine (PEI) onto the surface of cellulose triacetate (CTA) membrane was successfully performed. Pre-radiation and co-radiation were applied by gamma rays at the dose of 12 kGy. FT-IR, SEM, XPS, contact angle, zeta-potential, grafting ratio, etc. Were used to characterize the PEI-CTA membranes before and after grafting. The FT-IR spectrum showed that a notable discernible shoulder peak of N–H appeared for amide at co-radiation and pre-radiation, and XPS analysis indicated that co-radiation achieved the highest N percent of 9.75%, suggesting that PEI was introduced into the membrane surface. In a forward osmosis (FO) process, the PEI-CTA membrane obtained higher cesium, Cs(I), retention (95–97%) than the CTA membrane with Cs(I) retention of 92%. Cs(I) fluxes significantly decreased from 0.09 to 0.02–0.03 mmol m−2h−1 after PEI modification. Effective Cs(I) retention was attributed to increase of the positive charges on CTA membrane when PEI was added, which exerted a repulsive effect on Cs(I), preventing them from moving towards the membrane direction. In the FO process, the PEI-CTA membrane featured the water flux of 23 L m−2 h−1 a little lower than that of CTA membrane (24 L m−2 h−1). Although modified PEI increased the hydrophilicity, the increase of water flux did not occur with the co-irradiated membrane, which was related to the high graft, higher thickness and resistance of the membrane.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.