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In the application of forward osmosis, commercial nanofiltration (NF) membrane was modified via ultraviolet(UV)-photografting technique at different grafting parameters; monomer concentration (acrylic acid) and grafting time. However, the performance of the modified membrane measured at the osmotic pressure of 1M NaCl as draw solution limits their applications. In this research, the mathematical modelling was applied to predict the water flux at different osmotic pressure. The mathematical modelling indicated that the generated water flux follows the osmotic pressure but strictly affected by the grafting parameters. The result shows that at grafting time of 3min, the monomer concentration of 15 g/L generates the highest water flux followed by the membrane modified at the monomer concentration of 30 g/L. High water flux was attributed to the presence of strongly hydrophilic groups at new carboxyl layers leading to improved membrane properties. The approach of theoretical modelling on the membrane that is reported in this work allows estimating the water flux at different grafting parameter.

In this work, Classical Scaling (CMDS) method was used to develop a set of membrane profile performance for various types of UV-grafted polyethersulfone (PES) membrane. Previously, there is no such profiling has been considered. The main motivation of the profiling is to determine what is the most preference impact factor which significantly influence the membrane strength during application. Initially, nine (9) different samples of modified PES membranes were prepared mainly by adopting numerous characterization parameters of acrylic acid monomer concentration and grafting time. Three (3) performance indicators namely water permeability (A), solute permeability (B) and structural parameter (S) were used as representing the foundation of membrane performance profile. In particular, the Euclidean and City-block scales were utilized to build up the multivariate profile based on two dimension configurations. The key finding suggests that the modified membranes were easily clustered based on its grafting mechanism. From the general observation on the compressed CMDS dimensional space, samples that fall above the x-axis in Euclidean scale configuration and those scattered samples in the City-block scale have relatively larger pores. Thus, the CMDS profiling tends to favor the pore size as the dominant impact factor in characterizing the membrane performance based on the three specified parameters that investigated.