An in Situ Crystal Growth of Metal Organic Frameworks-5 on Electrospun PVA Nanofibers

Abstract

In this study, a simple, general and straightforward method for growing metal-organic frameworks (MOFs) crystals directly on nanofibers is presented. A chelating polymer was first blent with metal cation and then electrospun. The obtained nanofibers were immersed in a linker solution. Metal cations were released and the metal-organic frameworks crystals were grown on the fibers’ surface. In this work, this method was tested with polyvinyl alcohol as chelating polymer, Zn2+ as metal cation and Terephthalic acid as linker. The pair cation/linker corresponds to the MOF-5. The latter is a robust metal organic framework formed from Zn4O nodes with 1,4-benzodicarboxylic acid struts between the nodes. SEM images revealed that the MOF-5 nanocrystals have grown along the PVA/Zn2+ nanofibers that served as the crystals’ growth template by providing the Zn2+ ions. This result was also confirmed by infrared spectroscopy, which indicates the presence of characteristic bands of MOF-5 in the modified nanofibers spectrum. Moreover, the X-ray diffraction showed that MOF-5 material was well crystallized on the nanofibers surface according to a cubic symmetry with a space group Fm-3m and a lattice constant a = 25.8849 Å.

Keywords

• electrospinning
• functional textile
• metal organic frameworks
• hierarchical structures
• mof-5
• pva