| Autor: |
Duan P; Department of Chemistry , Brandeis University , Waltham , Massachusetts 02453 , United States., Moreton JC; Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States., Tavares SR; Institut Charles Gerhardt Montpellier UMR 5253 CNRS, Université de Montpellier , Place E. Bataillon , 34095 Montpellier Cedex 05 , France., Semino R; Institut Charles Gerhardt Montpellier UMR 5253 CNRS, Université de Montpellier , Place E. Bataillon , 34095 Montpellier Cedex 05 , France., Maurin G; Institut Charles Gerhardt Montpellier UMR 5253 CNRS, Université de Montpellier , Place E. Bataillon , 34095 Montpellier Cedex 05 , France., Cohen SM; Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States., Schmidt-Rohr K; Department of Chemistry , Brandeis University , Waltham , Massachusetts 02453 , United States. |
| Abstrakt: |
Solid-state NMR has been used to study mixed-matrix membranes (MMMs) prepared with a metal-organic framework (MOF, UiO-66) and two different high molecular weight polymers (PEO and PVDF). 13 C and 1 H NMR data provide overwhelming evidence that most UiO-66 organic linkers are within 1 nm of PEO, which indicates that PEO is homogeneously distributed throughout the MOF. Systematic changes in MOF 13 C NMR peak positions and 1 H NMR line widths, as well as dramatic reductions in the MOF 1 H T 1ρ relaxation times, are observed as the PEO content increases, and when the pores have been filled, a further increase in PEO results in the formation of semicrystalline PEO outside the UiO-66 particles. In contrast, similar studies on PVDF MMMs show that the polymer contacts only a small fraction (<20%) of the MOF linkers. Simulations confirm that PEO penetrates into UiO-66 more easily than does PVDF. These studies are among the first to provide experimental insights into MOF-polymer interactions in an MMM. |
