Rational design of dynamic fibre membrane for sustainable biofouling control

Current surface-controlled biofouling-based membrane technologies are retarded by short-run anti-biofouling performances. Dynamic fibre membrane, enriching the space and time of anti-biofouling agents acting on membrane, offers the potential to control biofouling in a continuous manner. We report the rational design and construction of a highly sustainable anti-biofouling dynamic fibre membrane, based on three interlocked criteria: (1) a three-dimensional space in the inner layer of fibre, halloysite nanotube (HNT), as ample active sites that load and release the biofilm inhibitor D-tyrosine; (2) a smart dynamic openness in the outer layer of fibre, polyvinylidene fluoride/polyacrylic acid semi-interpenetrating network polymer, as a continuous regulator that reloads D-tyrosine into HNT and re-releases it out of fibre; (3) electrospinning into dynamic fibre membrane. The dynamic fibre membrane-based ultrafiltration membrane exhibits exceedingly stable and sustainable anti-biofouling performance up to 185 days with only a 9.1% drop in reversible fouling recovery rate in a practical membrane bioreactor, far superior to the more than 40.4% decline of reversible fouling recovery rate within 75 days for the state-of-the-art anti-biofouling membranes. This systematic space–time-involved multidimensional membrane-construction concept opens a path of long-term sustainable running for membrane-based water treatment techniques.