Modulation of Hydrophilic/Hydrophobic Character of Porous Environments in Metal–Organic Frameworks via Direct Polymer Capping Probed by NMR Diffusion Measurements

VELASCO, MANUEL I.; ACOSTA, RODOLFO H.; MARMISOLLÉ, WALDEMAR A.; AZZARONI, OMAR; RAFTI, MATÍAS

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Lugar: Washington; Año: 2019 vol. 123 p. 21076 - 21082

1932-7447

The ability to create extended porous networks, such as those composed ofmetal−organic frameworks (MOFs), with tailored hydrophilic/hydrophobic character iscrucial for adapting such widely used supports to different applications. To achieve thisgoal, direct polymer inclusion has proven to be a suitable strategy, and functionalcomposite materials with multiple additional properties have been obtained in such a way.We have explored, by means of nuclear magnetic resonance diffusion experiments, theeffect of polymer capping using a conducting polymer (polyaminobencylamine, PABA),which results in the positioning of −NH2 moieties on the otherwise eminentlyhydrophobic surface of Zn-based ZIF-8 MOF nanocrystals. Our results demonstrate thatincreasingly higher amounts of PABA can confer, aside from conductivity, an increasedhydrophilic character to the porous network, while also allowing for the identification ofdifferent environments available for water molecule diffusion.