High-flux water desalination with interfacial salt sieving effect in nanoporous carbon composite membranes
KAUST DepartmentPhysical Sciences and Engineering (PSE) Division
Materials Science and Engineering Program
Extreme Computing Research Center
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
Advanced Membranes and Porous Materials Research Center
Chemical Science Program
KAUST Catalysis Center (KCC)
Chemical and Biological Engineering Program
Permanent link to this recordhttp://hdl.handle.net/10754/627420
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AbstractFreshwater flux and energy consumption are two important benchmarks for the membrane desalination process. Here, we show that nanoporous carbon composite membranes, which comprise a layer of porous carbon fibre structures grown on a porous ceramic substrate, can exhibit 100% desalination and a freshwater flux that is 3-20 times higher than existing polymeric membranes. Thermal accounting experiments demonstrated that the carbon composite membrane saved over 80% of the latent heat consumption. Theoretical calculations combined with molecular dynamics simulations revealed the unique microscopic process occurring in the membrane. When the salt solution is stopped at the openings to the nanoscale porous channels and forms a meniscus, the vapour can rapidly transport across the nanoscale gap to condense on the permeate side. This process is driven by the chemical potential gradient and aided by the unique smoothness of the carbon surface. The high thermal conductivity of the carbon composite membrane ensures that most of the latent heat is recovered.
CitationChen W, Chen S, Liang T, Zhang Q, Fan Z, et al. (2018) High-flux water desalination with interfacial salt sieving effect in nanoporous carbon composite membranes. Nature Nanotechnology. Available: http://dx.doi.org/10.1038/s41565-018-0067-5.
SponsorsCommercial PTFE membranes and FO membranes were provided by N. Ghaffour and T. Zhang from the KAUST Water Desalination and Reuse Center. Z.L. acknowledges support from KAUST (grant URF/1/1723) and KACST (grant RGC/3/1614). P.S. acknowledges support from KAUST (Special Partnerships Award number UK-C0016 and grant SA-C0040), HKUST (grant SRFI 11/SC02) and the William Mong Institute of Nanoscience and Technology (grant G5537-E).