Waterproof and breathable macroporous membranes that are both completely resistant to liquid water penetration and easily allowable to vapor transmission would have significant implication for numerous applications; however, fabrication of such materials has proven to be tremendously challenging. Herein, we reported novel electrospun composite fibrous membranes with high waterproof and breathable performance, which consisted of polyurethane (PU), terminal fluorinated polyurethane (FPU), and carbon nanotubes (CNTs). Benefiting from the utilization of FPU and CNTs, the fibrous membranes were endowed with superhydrophobic surface, optimized pores size and porosity, along with enhanced fibers, which resulted in excellent waterproof, breathable and mechanical properties. Significantly, the relationship among waterproofness, pore structure and surface wettability has been confirmed finely accordance with Young-Laplace equation. Ultimately, the resultant membranes presented high waterproofness with hydrostatic pressure up to 108 kPa, good breathability with water vapor transmission rate over 9.2 kg m(-2) d(-1), as well as robust mechanical properties with bursting strength of 47.6 kPa and tensile strength of 12.5 MPa, suggesting them as promising alternatives for a number of potential applications, such as protective clothing.

No abstract

Fouling of polymeric membranes remains a major challenge for long-term operation of oily-water remediation. The common reclamation methods to recycle fouled membranes have the issues of either incomplete degradation of organic pollutants or damage to filter membranes. Here, a calcinable polymer membrane with effective reclamation after fouling is reported, which shows full recovery of the original oil/water separation efficiency. The membrane is made of polysulfonamide/polyacrylonitrile fibers by emulsion electrospinning, followed by hydrothermal decoration of TiO nanoparticles. The bonding structured fibrous membrane displays outstanding thermal stability in air (400 °C), strong acid/alkali resistance (at the pH range from 1 to 13), and robust tensile strength. As a result, the chemically fouled polymeric membrane can be easily reclaimed without decreasing in separation performance and mechanical properties by annealing treatment. As a proof-of-concept, the as-prepared membrane is integrated into a wastewater separation tank, which achieves a high water flux over 3000 L m h and oil rejection efficiency of 99.6% for various oil-in-water emulsions. The presented strategy on membrane fabrication is believed to be an effective remedy for membrane fouling, and should apply in a wider field of filtration industry.

No abstract

No abstract