Abstract
We developed composite membranes by stacking functionalized nanospheres (20 nm size) with a high density of H-bonds. The functionalized nanospheres were formed by a click-reaction in toluene between the polybutadiene segment of poly(styrene-b-butadiene-b-styrene) (PS-b-PB-b-PS) triblock copolymer and an azodicarbonyl (PTAD) compound. The strong hydrogen-bond interaction promoted by the pendant urazole groups of the PTAD-modified copolymer is an important parameter for obtaining stable and defect-free membranes, acting in analogy to self-healing systems. The hydrodynamic transport is facilitated by the high porosity of the membranes and the unique hourglass-shaped pores. The composite membrane has water permeation as high as 60 L m−2 h−1 bar−1 and can exclude more than 95% of proteins with a molecular weight as small as 12 kg mol−1. This novel class of nanoparticle-stacked membranes has therefore excellent separation properties for biomolecular separation.
We acknowledge the funding by the King Abdullah University of Science and Technology (KAUST). We thank Cornell High Energy Synchrotron Source (CHESS) in the USA for the access to the GISAXS facility. CHESS is supported by the National Science Foundation and the National Institutes of Health/National Institute of General Medical Sciences under NSF award DMR-1332208.