PREPARATION AND CHARACTERIZATION OF IMPROVED HYDROPHILIC POLYETHERSULFONE/REDUCED GRAPHENE OXIDE MEMBRANE

Abstract

Polyethersulfone (PES)/reduced graphene oxide (rGO) membrane was prepared by phase inversion method for water treatment. Graphene oxide (GO) was obtained via modified Hummer’s method and reduced to rGO where NaBH4 was chosen as a reducing agent. FTIR was used to investigate functional groups left on rGO after reduction process. The FTIR peak at 1718 cm, attributed to the carbonyl (C=O) group, was absent after GO was reduced. Interlayer spacing of GO and rGO were obtained using XRD. It was found that the interlayer spacing of GO was reduced from 7.87 to 3.68 Å after reduction process due to the removal of some of the functional groups from the material. The membrane cross section showed that addition rGO increase the length of finger-like pores as compared to neat PES when it is observed under SEM. It was observed that the membrane hydrophilicity is enhanced as the contact angle of PES reduced from 69.70 to 32.99 when rGO 24 hours was introduced into the polymer matrix. The highest pure water flux obtained was 174.29 L/mh. The membranes showed significant enhancement when rGO was used in the polymer matrix. Keyword: polyethersulfone, phase inversion method, modified Hummer’s method, reduced graphene oxide Abstrak Membran polietersufon (PES)/grafin oksida terturun (rGO) telah dihasilkan melalui kaedah fasa terbalik untuk rawatan air. Grafin oksida (GO) dihasilkan menerusi kaedah Hummer terubahsuai dan diturunkan kepada rGO menggunakan NaBH4 sebagai ejen penurunan. FTIR digunakan untuk menyiasat kumpulan berfungsi yang hadir pada rGO selepas proses penurunan. Puncak FTIR pada 1718 cm yang menunjukkan kumpulan karbonil (C=O) tidak hadir selepas GO terturun. Jarak antara lapisan GO dan rGO telah dikaji menggunakan XRD. Didapati jarak antara lapisan GO berkurang daripada 7.87 Å ke 3.68 Å selepas proses penurunan kerana sebilangan kumpulan berfungsi telah terkeluar dari bahan. Keratan rentas membran menunjukkan bahawa penambahan rGO meningkatkan panjang liang seperti jejari berbanding PES asli apabila dilihat menggunakan SEM. Didapati bahawa sifat hidrofilik membran telah dipertingkatkan kerana sudut sentuh air PES telah berkurang dari 69.70 kepada 32.99 apabila rGO 24 jam ditambah ke dalam matriks polimer. Bacaan fluks air tulen tertinggi ialah 174.29 L/mh. Membran menunjukkan perubahan ketara apabila rGO digunakan di dalam matriks polimer. Kata kunci: polietersulfon, kaedah fasa terbalik, kaedah Hummer terubahsuai, grafin oksida terturun ISSN