Scalable Antifouling Reverse Osmosis Membranes Utilizing Perfluorophenyl Azide Photochemistry

Abstract

We present a method to produce anti-fouling reverse osmosis (RO) membranes that maintains the process and scalability of current RO membrane manufacturing. Utilizing perfluorophenyl azide (PFPA) photochemistry, commercial reverse osmosis membranes were dipped into an aqueous solution containing PFPA-terminated poly(ethyleneglycol) species and then exposed to ultraviolet light under ambient conditions, a process that can easily be adapted to a roll-to-roll process. Successful covalent modification of commercial reverse osmosis membranes was confirmed with attenuated total reflectance infrared spectroscopy and contact angle measurements. By employing X-ray photoelectron spectroscopy, it was determined that PFPAs undergo UV-generated nitrene addition and bind to the membrane through an aziridine linkage. After modification with the PFPA-PEG derivatives, the reverse osmosis membranes exhibit high fouling-resistance.

Improvement of performance and fouling resistance of polyamide reverse osmosis membranes using acrylamide and TiO2 nanoparticles under UV irradiation for water desalination

“…The hydrophilicity of modified membrane was increased and resistance of membranes to the bacteria adhesion and fouling was enhanced. Also, in another work, the surface modification of RO membrane was carried out by grafting of perfluorophenyl azide terminated PEG (PFPA‐PEG) with exposure the membrane surface to UV light . Although the pure water permeability of PEPA‐PEG‐grafted membrane was declined, the surface of grafted membrane became more hydrophilic and the salt rejection and fouling resistance were enhanced.…”

Layer-by-layer (LBL) assembly technology as promising strategy for tailoring pressure-driven desalination membranes

“…Secondly, although the surface grafting methods do not greatly increase hydraulic resistance, the reported research indicated that they could reduce the water flux. [72,74,76] To the contrary, the LBL method can well retain and sometimes even increase the water flux. [71] Thirdly, surface grafting bears the shortage that it might damage the membrane structure because the membrane need to be treated to generate monomer radicals.…”

“…Polymer brushes were attached through two ways. In the "graft to" form, the membrane is It should be noted that besides the LBL assembly, some other surface grafting methods, such as UV-induced grafting, [72,73,74] plasma grafting [75], and in situ crosslinked polymers brushes growth, [76] can also fabricate grafted hydrophilic layers on PA-TFC membranes surface without greatly increasing hydraulic resistance.…”

Fit-for-purpose block polymer membranes molecularly engineered for water treatment

“…126 Through the systematic macromolecular engineering of the block polymers, these coupling reactions should allow for a wide range of functional chemistries to be incorporated into membranes through the formation of resilient covalent bonds that form on a time scale consistent with the high throughput rollto-roll manufacturing of membranes on an industrial scale. 132,133 This, in turn, will allow the vast number of functional membrane chemistries for targeted water-based separations developed within academic settings to be translated to larger scales.…”