title: Ultrathin Free-Standing Bombyx mori Silk Nanofibril Membranes.
abstract: We report a new ultrathin filtration membrane prepared from silk nanofibrils (SNFs), directly exfoliated from natural Bombyx mori silk fibers to retain structure and physical properties. These membranes can be prepared with a thickness down to 40 nm with a narrow distribution of pore sizes ranging from 8 to 12 nm. Typically, 40 nm thick membranes prepared from SNFs have pure water fluxes of 13 000 L h(-1) m(-2) bar(-1), more than 1000 times higher than most commercial ultrathin filtration membranes and comparable with the highest water flux reported previously. The commercial membranes are commonly prepared from polysulfone, poly(ether sulfone), and polyamide. The SNF-based ultrathin membranes exhibit efficient separation for dyes, proteins, and colloids of nanoparticles with at least a 64% rejection of Rhodamine B. This broad-spectrum filtration membrane would have potential utility in applications such as wastewater treatment, nanotechnology, food industry, and life sciences in part due to the protein-based membrane polymer (silk), combined with the robust mechanical and separation performance features.
authors.affiliation: Department of Civil and Environmental Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.|Department of Biomedical Engineering, Tufts University , Medford, Massachusetts 02155, United States.
authors.forename: Shengjie
authors.initials: S
authors.lastname: Ling
authors.affiliation: Department of Civil and Environmental Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Kai
authors.initials: K
authors.lastname: Jin
authors.affiliation: Department of Biomedical Engineering, Tufts University , Medford, Massachusetts 02155, United States.
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
authors.affiliation: Department of Civil and Environmental Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Markus J
authors.initials: MJ
authors.lastname: Buehler
mesh_terms: D000818:Animals; D012831:Bombyx / Q000737:chemistry*; D004396:Coloring Agents / Q000302:isolation & purification; D005374:Filtration / Q000295:instrumentation; D008567:Membranes, Artificial; D057139:Nanofibers / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D036103:Nanotechnology; D010316:Particle Size; D016062:Porosity; D011506:Proteins / Q000302:isolation & purification; D012235:Rhodamines / Q000302:isolation & purification; D047011:Silk / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification
chemical_list: D004396:Coloring Agents; D008567:Membranes, Artificial; D011506:Proteins; D012235:Rhodamines; D047011:Silk; D014874:Water Pollutants, Chemical; C029773:rhodamine B
keywords: Silk nanofibrils; filtration; separation; ultrathin membrane