Self-Assembled Mesoporous Zeolitic Imidazolate Framework-8 (ZIF-8) Nanocrystals Bearing Thiol Groups for Separations Technologies

SEGOVIA, GUSTAVO M.; TUNINETTI, JIMENA S.; AZZARONI, OMAR; RAFTI, MATÍAS

ACS Applied Nano Materials

ACS

Lugar: new york; Año: 2020

2574-0970

ABSTRACT: Colloidal suspensions of Zn-based ZIF-8 Metal Organic Framework (MOFs) particleswere synthesized (both micrometer µ-ZIF-8, and nanometer n-ZIF-8 sized respectively). Post-syntheticmodification was carried using 2-amino-ethanethiol (cysteamine or Cys), a thiol-bearing monodentateligand, and particles obtained were employed for the assembly of films on gold-coated electrode surfaces.The results obtained show that, aside from conferring chemical affinity towards Au, when suitable molarratios are employed cysteamine modification causes partial coordinative chemical etching of inherentlymicroporous ZIF-8 units, thus giving rise to additional mesoporosity. Cysteamine concentration andexposure time were found to act as control parameters ultimately determining transport properties ofporous films obtained, which can then feature, e.g., size-exclusion effects. The colloidal modificationstrategies like the one hereby described can be employed for the preparation of robust nano-organizedMOF thin films with hierarchical porosity, which bear great potential for its application in separationtechnologies.