Smart thermo-responsive polyvinylidene fluoride membranes with superior gating characteristics

Controllable permeation through porous membranes is highly desirable for membrane applications such as selective separation and smart filtration. However, the conventional forms of thermo-responsive polyvinylidene fluoride (PVDF) membranes fabricated by liquid induced phase separation method lack dynamic permeability tunability and exhibit poor mechanical properties. Herein, we show a simple method to enable thermoresponsive permeability in PVDF membranes by incorporating poly(N-isopropylacrylamide) (PNIPAM) microgels. By virtue of temperature tunable pore size of smart PVDF/PNIPAM membranes (PPMs), the water permeance could be reversibly regulated from 10.3 kg m- 2 h- 1 bar- 1 at 20 degrees C to 13881 kg m- 2 h- 1 bar- 1 at 45 degrees C, achieving a record high normalized water gating ratio of 805. Moreover, the proposed membranes also show superior mechanical properties with maximum tensile stress and strain at break of 5.9 MPa and 56.2 %, respectively. These findings provide valuable guidance on constructing smart membranes with superior gating characteristics in potential applications for smart valves etc.