05069ntm a2200337 i 4500 MY-KuUP 20261008113622.0 t||||fr|||| 000 0 ta 261008t20262026my a|||fr|||| 000 0 eng d THE0010836 (Local) Hardback UMPSA eng UMPSA rda FTKKP .H36 2026 r Thesis Hamza Ennaji Omran Almansouri, author. Development of carbon-based nanomaterials-enhanced thin-film composite membranes for forward osmosis seawater desalination / Hamza Ennaji Omran Almansouri Kuantan, Pahang : UMPSA, 2026 © 2026 xviii, 244 pages : illustration ; 30 cm.+ 1 CD-ROM rdacontent text rdamedia unmediated rdacarrier volume rda text file PDF Faculty of Chemical and Process Engineering Technology Thesis (Doctor of Philosophy) -- Universiti Malaysia Pahang Al Sultan Abdullah - 2026 Include bibliographical reference This study investigates the development of carbon-based nanomaterial-enhanced thinfilm composite (TFC) membranes for efficient forward osmosis (FO) seawater desalination. Two nanomaterials with different dimensionalities were investigated: onedimensional (1-D) carboxyl-functionalized multiwalled carbon nanotubes (COOHMWCNTs) and two-dimensional (2-D) graphene oxide (GO) nanosheets. The two nanomaterials were strategically incorporated into the polyethersulfone (PES) support layer, the polyamide (PA) selective layer, and both layers to evaluate their effects on FO performance and antifouling properties. For the support layer, COOH-MWCNTs and GO were incorporated into PES substrates at loadings of 0.1 0.75 wt.%, whereas for the PA layer, they were introduced during interfacial polymerization at loadings of 100 850 ppm. The loadings were systematically optimized for each layer, and the optimum loadings were subsequently employed for dual-layer modification to investigate the synergistic effects. The control membrane (TFC-0) exhibited low water flux (2.86 LMH), poor selectivity (9.34 g/L), high flux decline (55.18%), and low flux recovery (72.3%). Incorporating COOH-MWCNTs into the PES support at the optimum loading of 0.5 wt.% (TFC-MW3) improved water flux (7.48 LMH), selectivity (8.8 g/L), flux decline (37.81%), and flux recovery (91.92%). The GO-modified PES support at 0.1 wt.% (TFCGO1) achieved moderate flux (5.12 LMH) but higher selectivity (4.95 g/L), lower flux decline (35.67%), and higher flux recovery (97%). MWCNTs enhanced water passage through 1-D nanochannels, while GO nanosheets provided 2-D capillary channels that enhanced solute selectivity. Both modifications also strengthened the PES substrates, with MWCNTs providing higher tensile strength owing to the strong graphitic bonds of carbon nanotubes. COOH-MWCNTs incorporated into the PA layer at 350 ppm (TFNMW350) yielded a water flux of 5.86 LMH, selectivity of 4.36 g/L, reduced flux decline (42.76%), and high flux recovery (96.68%). GO nanosheets at 850 ppm (TFN-GO850) achieved higher flux (7.79 LMH), stronger selectivity (2.05 g/L), slightly higher flux decline (51%), and excellent flux recovery (99.47%). Accordingly, PA-layer modification achieved greater selectivity improvement than support-layer modification, highlighting the role of direct nanomaterial incorporation into the selective layer. Duallayer modification further improved performance, with the GO-modified both-layer membrane (TFN-BL-GO) achieving the highest water flux (8.67 LMH) and the best selectivity (1.75 g/L) across all membrane configurations, while exhibiting a flux decline of 47% and a flux recovery of 97%. The COOH-MWCNTs-modified both-layer membrane (TFN-BL-MW) achieved a water flux of 7.27 LMH, higher than the TFNMW350 membrane but lower than the TFC-MW3, with improved selectivity (2.63 g/L), flux decline of 48%, and a flux recovery of 100%. Both-layer modification integrated the advantages of the support and PA layers, delivering balanced improvements in flux, selectivity, and fouling reversibility. Under real seawater conditions, PA-layer-modified membranes exhibited more stable performance than support-layer-modified membranes, while dual-layer-modified membranes achieved the highest and most stable water fluxes, with TFN-BL-MW and TFN-BL-GO retaining 91.3% and 83.6% of their initial flux, respectively. Notably, trends observed under real seawater conditions differed from laboratory-controlled foulant tests, underscoring the importance of validation using real seawater. Overall, this study demonstrates that carbon-based nanomaterials can significantly enhance FO performance, with nanomaterial dimensionality (1-D vs. 2-D) and incorporation strategy playing critical roles. Faculty of Chemical and Process Engineering Technology Dissertations Universities and colleges Dissertations Theses Dissertations lcc THESIS 0 0 lcc 0 6 REF 10000 10000 2026-10-08 0 FTKKP .H36 2026 r Thesis T000005670 2026-10-08 11:37:06 1 2026-10-08 RESTRICT 0 0 lcc 0 6 REF 10000 10000 2026-10-08 0 CD14074 T000005671 2026-10-08 11:37:46 1 2026-10-08 RESTRICT 105699 105705