Abstract
We report gas and liquid transport measurements through membranes that have 40% voids made of 14 nm pores. A reactive polylactide- polynorbornenylethylstyrene block polymer is used as a structural template in the polymerization of dicyclopentadiene during the membrane formation process. After the membrane is cast, the pore structure is formed by etching the polylactide component using dilute aqueous base. The pore structure is isotropic; therefore, there is no need for special alignment techniques. Knudsen diffusion experiments and water flow experiments show pores with a tortuosity of 1.81 and a size of 14 nm, a diameter consistent with nitrogen adsorption and small-angle X-ray scattering measurements. These membranes are effective for ultrafiltration, with molecular weight cutoffs (MWCO) consistent with theoretical predictions with no adjustable parameters. These MWCOs can be tuned by changing the size of the constituent blocks in the templating copolymer.
Original language | English (US) |
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Pages (from-to) | 472-480 |
Number of pages | 9 |
Journal | ACS Applied Materials and Interfaces |
Volume | 1 |
Issue number | 2 |
DOIs | |
State | Published - Feb 25 2009 |
Keywords
- Knudsen diffusion
- block copolymers
- filtration
- nanoporous membranes