SELF-ASSEMBLY OF FILMS ON ELECTROACTIVE SUBSTRATE WITH CONTROLLED MICRO AND MESOPOROSITY

GUSTAVO SEGOVIA, MATIAS RAFTI, OMAR AZZARONI

San Pablo

Workshop; Autoorg 2018; 2018

FAPESP

Microporous Coordination Polymers - MCPs, also known as Metal Organic Frameworks (MOFs) are an emerging class of microporous crystallinematerials composed of metal nodes (or clusters containing metals) coordinated with polydentate organic ligands. A great part of MOFs appeal, resultsfrom the multiple possible combinations between metal centers and organic ligands, leading to a continuously increasing number of applications; e.g.,separations1, catalysis2, drug-delivery3, electrochemistry4 and greenhouse effect capture agents5.ZIF-8 (see figure 1) modified with cysteamine nanocrystals were used as building blocks for the self-assembly (via thiol chemisorption) of films on goldsubstrates and the films surface was characterized by atomic force microscopy. A mesoporosity appears as consequence of the ZIF-8 nanocrystalsself-assembly having a size depending of MOF size. We characterized the resulting mesoporosity studying the diffusion of a redox probe through thefilm.The porosity of resulting films was characterized evaluating (1 mM)Fe(CN)63- / (1 mM) Fe(CN)64- redox probe diffusion in 100 mM KClaqueous solution by cyclic voltammetry on the ZIF-8+Cys films at 50mV/s.