Isoporous membrane from PS-b-PAA/MWCNT-Ag composite with high photothermal conversion efficiency

Isoporous membranes from a process coupling the self-assembly of block copolymer with nonsolvent-induced phase separation (SNIPS) could enhance both the permeability and selectivity due to the high pore density and uniform pore sizes. Whereas, it is difficult to precipitate PAA based block copolymer in nonsolvent to make membranes because PAA blocks are hydrophilic. Herein, isoporous PS₆₇₈-b-PAA₁₈₀ membranes were well prepared after reinforced by multiwalled carbon nanotubes decorated with silver nanoparticles (MWCNT-Ag). Such composite membranes bear not only regular channels with an effective pore diameter of ca. 18.85 nm, but also high water permeance of 1770.35 L bar⁻¹ m⁻² h⁻¹. With the participation of carbon nanotubes, the PS-b-PAA isoporous membrane exhibits excellent photothermal conversion properties, which endows the membrane with an efficiency of ca. 10.6 kg m⁻² h⁻¹ for light energy-driven seawater desalination and wastewater purification. Moreover, the silver particle-decorated CNTs enable the membrane to be antibacterial, which ensures reliability in long-term application.