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Title:	Hydrothermal pre-treatment on oil palm empty fruit bunch cellulose for the production of ion-selective graphene oxide-cellulose membrane
Authors:	Khairunnisa Waznah Baharin (P83417)
Supervisor:	Sarani Zakaria, Prof. Dr.
Keywords:	Cellulose Oil palm empty fruit bunch (OPEFB) Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia
Issue Date:	13-Oct-2021
Description:	The oil palm empty fruit bunch (OPEFB) which is one of the biomass waste obtained after the extraction of palm oil are abundantly available sources of cellulose yet underexplored in Malaysia. Cellulose is the most abundant organic polymer on earth and in this study, OPEFB��s cellulose was dissolved in cellulose solvent to form regenerated cellulose membranes (RCM) with added graphene oxide (GO). However, OPEFB��s cellulose showed low solubility (40 wt%) when dissolved in aqueous NaOH-urea solvent, which is inadequate for the formation of RCM. Therefore, OPEFB��s cellulose were compared with reference cellulose and analyzed in terms of its fibre structure, average viscosity molecular weight (Mη), chemical constituent, zero-span tensile strength, and the crystallinity index (CrI) to determine the factors affecting OPEFB cellulose dissolution in aqueous NaOH-urea solvent. Research findings showed that the most significant factor is the high Mη (1.68 x 105). In this study, hydrothermal pretreatment at varied temperature (140, 150, and 160 �C) and reaction time (1, 2, and 3 h) was done on OPEFB��s cellulose to find the optimum parameter in reducing the Mη. The treated OPEFB��s cellulose (HEFB) was then casted into RCM and characterized to study its physical and mechanical properties. Temperature of 160 �C and 1 h time was selected as the optimum pretreatment parameter. Then, the pretreated OPEFB��s cellulose and GO at different GO percentage (1, 3, 5, 7, and 9%) was combined and regenerated into membrane (RCGO) to study its physical properties and its application in desalination. The GO was synthesized by Hummer��s method with slight modification and confirmed by fourier transform infra-red (FTIR) spectroscopy and RAMAN analysis. Cellulose matrix acts as backbone for GO through hydrogen bond formed between hydroxyl functional group of cellulose and oxygenated functional group of GO. The water contact angle result showed the hydrophilic properties of RCGO membrane increases with increasing GO percentage. The thermogravimetric analysis (TGA) result showed addition of 1, 3 and 5% GO had improved the RCGO��s membrane thermal stability up to 600 �C while increasing more GO dropped the result significantly. This is because rapid degradation of GO occurred due to the excellent thermal diffusion of GO. Through a simple permeation analysis and salt rejection calculation, it was demonstrated that RCGO membrane can act as ion-selective filtration membrane. The cross section images of RCGO membrane obtained from scanning electron microscopy (SEM) revealed dense structure of cellulose network and layered GO sheet which provide a torturous pathway for ion to pass through the membrane. However, the RCGO-7 and RCGO-9 membrane��s surface shows presence of fine pore (34.5��48.5 nm) when observed under helium ion microscope (HIM). The formation of pores was due to the inhomogeneity between cellulose and GO during mixing and regeneration process. RCGO membrane with 3 % GO showed the lowest ion conductivity reading (3500 μS/mm) and highest salt rejection percentage among all sample when placed between deionized water and saline solution (35 ppt NaCl) in 3 h observation time. As a conclusion, the hydrothermal pretreated OPEFB��s cellulose was successfully regenerated into RCM and RCGO membrane with the potential to be used as ion-selective filtration membrane especially in the water treatment system.,Ph.D
Pages:	116
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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