A study on producing composite nanofiltration membranes with optimized properties

In this study, we attempt to produce nanofiltration membranes with varying properties through interfacial polymerization technique. The properties include pore size, effective charge density and effective membrane thickness. The ability to use NF membranes with varying properties will improve overall process efficiency as shown in our previous study. The membranes produced were characterized using permeation experiments with water, salt and uncharged solute as well as imaging using atomic force microscopy (AFM). This study has shown that through interfacial polymerization technique, the variation of reaction time as well as monomer concentrations can affect the properties of the membrane produced. Increasing the reaction time resulted in decreasing water permeabilities but based on AFM imaging, the pore size was of similar value. Increasing the monomer concentration also resulted in decreasing water permeabilities. However, based on AFM imaging the pore size differs considerably. Additional permeation experiments and data interpretation with predictive model such as DSPM model allow further understanding of the variation of membrane properties. The ability to tailor made TFC membrane with the right properties will significantly improved processing efficiency.