Asymmetric Solvent‐Annealed Triblock Terpolymer Thick Films Topped by a Hexagonal Perforated Lamellar Nanostructure

Abstract

Back Cover: In article number 2100585 by Karim Aissou and co‐workers, a nanoporous layer of perforated lamellae (PL) is produced on top surface of asymmetric triblock terpolymer membranes generated by non‐solvent induced phase separation. The thickness of the PL phase is adjusted by varying the duration of the solvent vapor annealing (SVA) treatment.

Double stimuli‐responsive perforated lamellar structure formed by linear ABC triblock terpolymer monoliths

“…To study the thermo‐responsive behavior, the water fluxes of solvent‐annealed (6 h, CHCl 3 ) PS‐ b ‐P2VP‐ b ‐PNIPAM monoliths were recorded at temperatures well below and above the LCST transition of the PNIPAM block (~32°C) under neutral pH conditions (pH = 7) (see Figure 4A). Prior to do the measurement, the PS‐ b ‐P2VP‐ b ‐PNIPAM monoliths generated by NIPS‐SVA were deposited on a highly permeable polyvinylidene difluoride (PVDF) support and the permeance was then plotted as the function of the water pressure applied from 0.5 to 2 bar, using a dead‐end stirred ultrafiltration cell 23 . The PS‐ b ‐P2VP‐ b ‐PNIPAM monoliths demonstrated an excellent stability over failure even at high feed pressure (over 2 bar) since a linear change in water flux with the increase in pressure drop is observed regardless of the temperature (20°C and 46°C).…”

“…This continuous flow system was used to control the CHCl 3 vapor pressure in the chamber by dilution with a separate N 2 stream so that a solvent vapor consisted of 32 sccm CHCl 3 vapor and 8 sccm N 2 (total 40 sccm). Note that the NIPS process was initially used to generate asymmetric terpolymer films after the SVA treatment 23 . However, a long SVA time (>2 h) was required to achieve well‐defined nanopores on the material top surface, making that only symmetric terpolymer films entirely composed of the PL phase were finally considered in this work.…”

“…The water permeability of the different PS‐ b ‐P2VP‐ b ‐PNIPAM thick films was measured in a 10 ml filtration cell (Amicon 8010 stirred cell) connected to a water reservoir and a compressed air line. The measurements were performed on 2.5 cm diameter PS‐ b ‐P2VP‐ b ‐PNIPAM material discs supported by a high permeable hydrophilic PVDF material (water permeability of ~2900 L h −1 m −2 bar −1 ) 23 at pressures between 0.5 and 2 bar. The mass of water passing through the stacked materials (permeate) was recorded using a connected balance at regular time intervals for 10 min.…”

Square arrays of vertically aligned nanoporous cylinders from a linear ABC triblock terpolymer

“…The water permeability of the different PDMSB‐ b ‐PS‐ b ‐P2VP thick films was measured in a 10 mL filtration cell (Amicon 8010 stirred cell) connected to a water reservoir and a compressed air line. The measurements were performed on 2.5 cm diameter PDMSB‐ b ‐PS‐ b ‐P2VP material discs supported by a high permeable hydrophilic PVDF material (water permeability of ~2900 L h −1 m −2 bar −1 ) 48 in order to achieve reproducible measurements between 0.5 and 2 bar, notably by avoiding large deformations (and eventually ruptures) of the terpolymer film when the pressure drop is higher than 1.5 bar. The mass of water passing through the stacked materials (permeate) was recorded using a connected balance at regular time intervals for 7 min.…”