Composite Membranes with Nanofibrous Cross-Hatched Supports for Reverse Osmosis Desalination

Abstract

A novel membrane structure comprised of cross-hatched electrospun nanofibers is developed. We illustrate that this novel structure allows for much higher water permeability when used as a support for reverse osmosis thin-film composite membranes. Reinforcement and lamination of the aligned nanofibres generates mechanically robust structures that retain very high porosity and low tortuosity when applied to high pressure seawater desalination operations. The cross-hatched nanofibre layers support the polyamide active layer firmly and reduce resistance to water flow due to the high porosity, low tortuosity, high mechanical strength and minimal thickness of the structures. The nanofibre composite membrane gives a water flux significantly greater than when a traditional support layer is used, at 99 ± 5 m -2 h -1 with NaCl rejection of 98.7 % at 15.5 bar.

Synthesis and Water Treatment Applications of Nanofibers by Electrospinning

“…Higher water flux and salt rejection were observed in thinfilm composite RO membranes synthesized using polyacrylonitrile (PAN) [66] and cellulose nanofibers [67,68]. A crosshatched nanofiber membrane modified by dopamine [69] showed high water flux and salt rejection (>95%), which was still lower than MD membranes that showed rejection of more than 99%. Nevertheless, these membranes show better anti-fouling behavior than many other RO membranes.…”

All-weather-available electrothermal and solar–thermal wood-derived porous carbon-based steam generators for highly efficient water purification

“…where Z se is the total energy conversion efficiency of the evaporator with solar energy and electrical energy, n is the water evaporator rate, H LV is the total enthalpy of sensible heat and latent vaporization heat, and Q in is the total energy input including the solar energy and the electrical energy. Besides, the electrical energy input (Q e ) is calculated using eqn (4).…”

“…As reported, approximately 3.7 billion people are faced with clean water scarcity, and the number could increase to 5.7 billion until 2025. 1 Traditional seawater desalination technologies, including reverse osmosis membrane separation, [2][3][4] ion exchange, 5,6 and thermal distillation, 7,8 have shortcomings of high energy consumption, complicated manufactory, and high cost. Solardriven steam generation is believed to be one of the environmentfriendly water purification techniques because it is driven by the clean and pollution-free solar energy and can alleviate environmental pollution effectively.…”

A review of recent progress in polymeric electrospun nanofiber membranes in addressing safe water global issues

“…The resultant ENMs were able to show better performance than the commercial traditional membranes by exhibiting permeation flux of 51 ± 2 L m −2 h −1 and salt rejection between 98–99%. 150 When fabricating TFNC RO ENMs, the importance has to be given to the effect of porous nanofibrous support layer on the formation of thin barrier layer by interfacial polymerization. The optimization of porosity and thickness, and enhancement of hydrophilicity of the barrier layers may be the effective research direction for the development of high-performance TFNC RO ENMs.…”