Polymer Infiltration into Metal–Organic Frameworks in Mixed-Matrix Membranes Detected in Situ by NMR

Abstract

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). 13C and 1H 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 13C NMR peak positions and 1H NMR line widths, as well as dramatic reductions in the MOF 1H 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.

Structuring Metal–Organic Framework Materials into Hierarchically Porous Composites through One‐Pot Fabrication Strategy

“…Moreover, the interaction between HKUST‐1 and PVDF was responsible for the formation of mesopores in both MOF crystals and PVDF matrix, because the direct evaporation of pure HKUST‐1 precursor solution led to microporous crystals only (Figure f) and the porous PVDF matrix prepared by washing‐off HKUST‐1 crystals with acid showed a distinct mesoporous morphology from the original HKUST‐1/PVDF sample (Figure S4). The interaction might be due to the intermolecular interactions between the organic part of the MOF and the polymer similar to the reported literature . In addition, to further illustrate the universality of this method, Cu‐BDC/PVDF was prepared through the same process and showed a similar porous structure (Figures S5 and S6).…”

“…The interaction might be due to the intermolecular interactions between the organic part of the MOF and the polymers imilar to the reportedl iterature. [20] In addition, to further illustrate the universality of this method, Cu-BDC/PVDF wasp repared throught he same process and showedasimilarporousstructure ( Figures S5 and S6). Introduction of the hierarchical pores greatly increased the diffusionr ate of guest molecules, which is desirable in applications, such as gas adsorption, molecular separation, and heterogeneous catalysis.…”

Loading‐Dependent Structural Model of Polymeric Micelles Encapsulating Curcumin by Solid‐State NMR Spectroscopy

“…Horizontal slices indicate that the peak centre for the cross‐peak at 128 ppm (green) is at lower ppm values than the OMe resonance (grey), but CUR–CUR contacts or intramolecular spin‐diffusion cannot be fully excluded as a source of this cross‐peak. A HETCOR spectrum with an additional spin‐diffusion block of 50 ms according to Duan et al . showed spin diffusion between the different components (Figure S12 a).…”

A novel composite derived from a metal organic framework immobilized within electrospun nanofibrous polymers: An efficient methane adsorbent

“…High manufacturing cost should be considered as one of the main obstacles toward the commercialization of many MOF compounds . In order to develop a facile synthesis process for production of inexpensive MOFs, numerous manufacturing processes have been studied under a variety of conditions.…”