Toward the goal of integrating metal-organic frameworks (MOFs) into device architectures for applications such as chemical sensing and energy storage, our research explores the bottom-up formation of surface-anchored MOFs (surMOFs). Our initial studies focused on copper-paddlewheel based surMOF systems, such as HKUST-1, MOF-14, and MOF-399, fabricated on carboxylic-acid terminated self-assembled monolayers (SAMs) via layer-by-layer (LBL) solution-phase deposition. We characterize ultra-thin films of these surMOFs by atomic force microscopy (AFM), ellipsometry, x-ray diffractometry, infrared spectroscopy, and contact angle goniometry. Building on our previous work, we are studying how the interfacial SAM impacts surMOF growth, expanding the copper-paddlewheel systems studied systematically by AFM, and exploring surMOF film formation via spray deposition methods. To investigate how the interfacial SAM affects surMOF assembly, characterization was conducted to observe surMOF formation and morphology on SAMs composed of mixed methyl- and carboxyl-terminated alkanethiols. Insights are applied to optimize microcontact printing for directed surMOF assembly. As methyl-terminated alkanethiol SAMs are often used to inhibit surMOF formation, we are exploring the effectiveness of this inhibition for methyl-terminated SAMs with different chain lengths (i.e. adamantanethiol, octanethiol, octadecanethiol) and with different quality of ordering (due to different deposition conditions). Expanding to other copper-paddlewheel systems, we are characterizing the growth of the MOF-2 system and have found that the chemical functionality of the SAM directs film formation and crystal orientation. Quantitative image analysis is utilized to describe the surMOF growth in terms of roughness, surface coverage, and average crystallite size. Currently, we are undertaking spray deposition, which is faster and reduces chemical consumption, for formation of copper-paddlewheel surMOF systems that we have also studied by solution-phase LBL. A comparison of these results will presented alongside key variables identified to tune morphological features. This presentation will highlight key variables that control the supramolecular assembly of ultrathin surMOF films.

Investigating the impact of interfacial interactions on the formation and morphology of surface-anchored metal-organic frameworks

Where thousands of chemistry professionals meet to share ideas and advance scientific and technical knowledge. Spring 2023 abstracts, posters, and presentations will launch at the end of March.

ACS Spring 2023

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.