Control of ZIF-62 and agZIF-62 Film Thickness within Asymmetric Tubular Supports through Pressure and Dose Time Variation of Atomic Layer Deposition.

Abstract

Thin-films of metal-organic frameworks (MOFs) have widespread potential applications, especially with the emergence of glass-forming MOFs, which remove the inherent issue of grain boundaries and allow coherent amorphous films to be produced. Herein, it is established that atomic layer deposition (ALD) of zinc oxide lends excellent control over the thickness and localization of resultant polycrystalline and glass zeolitic imidazole framework-62 (ZIF-62) thin-films within tubular α-alumina supports. Through the reduction of the chamber pressure and dose times during zinc oxide deposition, the resultant ZIF-62 films are reduced from 38µm to 16µm, while the presence of sporadic ZIF-62 (previously forming as far as 280µm into the support) is prevented. Furthermore, the glass transformation shows a secondary reduction in film thickness from 16 to 2µm.