Department of Civil and Environmental Engineering, Rice University, Houston, TX, USA.
NSF Nanosystems Engineering Research Center Nanotechnology-Enabled Water Treatment (NEWT), Rice University, Houston, TX, USA.
Nat Nanotechnol. 2020 Dec;15(12):1025-1032. doi: 10.1038/s41565-020-00777-0. Epub 2020 Oct 26.
Surface heating membrane distillation overcomes several limitations inherent in conventional membrane distillation technology. Here we report a successful effort to grow in situ a hexagonal boron nitride (hBN) nanocoating on a stainless-steel wire cloth (hBN-SSWC), and its application as a scalable electrothermal heating material in surface heating membrane distillation. The novel hBN-SSWC provides superior vapour permeability, thermal conductivity, electrical insulation and anticorrosion properties, all of which are critical for the long-term surface heating membrane distillation performance, particularly with hypersaline solutions. By simply attaching hBN-SSWC to a commercial membrane and providing power with an a.c. supply at household frequency, we demonstrate that hBN-SSWC is able to support an ultrahigh power intensity (50 kW m) to desalinate hypersaline solutions with exceptionally high water flux (and throughput), single-pass water recovery and heat utilization efficiency while maintaining excellent material stability. We also demonstrate the exceptional performance of hBN-SSWC in a scalable and compact spiral-wound electrothermal membrane distillation module.
表面加热膜蒸馏克服了传统膜蒸馏技术固有的一些局限性。在这里，我们成功地在不锈钢金属网上原位生长了六方氮化硼（hBN）纳米涂层（hBN-SSWC），并将其用作表面加热膜蒸馏中可扩展的电热加热材料。新型 hBN-SSWC 具有优异的蒸汽透过性、导热性、电绝缘性和耐腐蚀性，所有这些特性对于长期的表面加热膜蒸馏性能都至关重要，特别是对于高盐溶液。通过简单地将 hBN-SSWC 附着在商业膜上，并使用家用频率的交流电提供电源，我们证明 hBN-SSWC 能够支持超高的功率密度（50kWm），以极高的水通量（和通量）、单级水回收率和热利用率从高盐溶液中脱盐，同时保持优异的材料稳定性。我们还展示了 hBN-SSWC 在可扩展和紧凑的螺旋缠绕电热膜蒸馏模块中的卓越性能。
