Synthesis, characterization and surface modification of PES hollow fiber membrane support with polydopamine and thin film composite for energy generation

• Implications of the results for power generation by PRO are evaluated and discussed.
• Demonstrated the effect of MPD, PIP and TMC monomers on dopamine coated HFM for PRO performance.
• The TFC-HF membranes show enhancements in both water flux and power density.
• Made an overall comparison and discussion of hollow fiber aspect design.

To develop a high flux and high power density the polyethersulfone (PES) membrane support was modified by coating with polydopamine (PDA), based on the easy self-polymerization and strong adhesion characteristics of dopamine (DA) under mild conditions. After polydopamine coating the effect of thin film composite (TFC) on polydopamine layer was studied. The surface morphological changes were characterized using SEM. The influence of the modifying conditions such as coating time and DA concentration on the membrane properties was investigated. It was found that the most reasonable modification conditions to obtain the high power density performance are 0.2 g/l DA concentration with 1 h coating time. After PDA coating the TFC active layer was prepare on the surface of coated membrane. There was tremendous increment of the flux for the polydopamine coated thin film composite (PDA-TFC) membrane under the best conditions compared with that of the original membrane (PES substrate). The result showed that the PDA-TFC membrane has higher flux, excellent power density performance and good stability. The results by using these membranes were promising, indicating that the modified membranes exhibited an increase in flux performance under testing conditions when compared to baseline control data. This modification method, which is scalable, has the potential to enable the use of existing thin film composite membranes for all engineered osmosis applications. This work provides a simple method of modifying PES membrane for better performance and potential application in pressure retarded osmosis (PRO).