Thin Film Growth of nbo MOFs and their Integration with Electroacoustic Devices

Abstract

Metal‐organic frameworks (MOFs) with the “nbo” topology constitute a diverse suite of more than 100 nanoporous materials, but their use in applications such as chemical sensing and membranes is inhibited by a lack of methods for growing them as thin films. Here, layer‐by‐layer (LBL) and solvothermal growth of “nbo” films is demonstrated and it is established for the first time that interlinker steric hindrance is a critical factor in determining the effectiveness of the LBL method. Film growth is demonstrated for three “nbo” MOFs: NOTT‐100 and NOTT‐101, which have the R‐3m space group and are deposited by the LBL method, and PCN‐14, with the R‐3c space group, which is deposited by a solvothermal approach. Continuous and dense films of NOTT‐100 and NOTT‐101 are obtained and LBL growth is verified by observing deposition with a quartz crystal microbalance technique, which also yields the temperature dependence. Oxygen plasma treatment is found to be a useful tool for promoting the MOF film growth under solvothermal conditions. Effective mechanical coupling of these films to the substrate is demonstrated by growing them on surface acoustic wave sensors, which respond reversibly to vapors of water, acetone, and n‐hexane.

Tuning optical properties of MOF-based thin films by changing the ligands of MOFs

“…The R a of MIL-101(Cr), NH 2 -MIL-101(Cr), and NO 2 -MIL-101(Cr) thin films are only 3.4, 3.0, and 4.2 nm, respectively. The R q of them are 4.4, 3.8, and 5.5 nm, which are smaller than those of MOF-based thin films in previous reports [18,34,35]. For instance, Demessence et al [18] reported that the root-mean-square roughness of MIL-101(Cr) optical thin films was calculated to be around 12 nm (nearly half of the MOF NP diameter).…”

Crystalline, Highly Oriented MOF Thin Film: the Fabrication and Application

“…At present, most of the well‐known crystalline‐oriented thin films are fabricated by this method. A number of MOF films contain the SBU's like dimeric species (SBU: secondary building unit, such as copper paddlewheel unit) or some containing more than one type of ligands have been developed by this method, such as [Cu 2 (ndc) 2 (dabco)] . This method can be used to prepare the highly oriented thin film of MOFs with 2D layered structure, such as [M 2 (bdc) 2 (H 2 O) 2 ] (M: Zn 2+ , Cu 2+ ; bdc: benzdicarboxylate).…”

Coffee Ring–Inspired Approach toward Oriented Self‐Assembly of Biomimetic Murray MOFs as Sweat Biosensor

“…Modular architecture of MOFs allows for regulation of network topology, structure metrics, along with coordination chemistry, which holds striking promise in extensive applications such as sensing, catalysis, gas storage, energy, and molecular separations . Nevertheless, given the relevance between reaction parameters and synthetic outcome, it can always be hard to predict the size, morphology, distribution, and orientation of targeted MOFs . More importantly, progress in these applications especially for electrochemical devices and biosensing system has been restricted by poor conductivity, slow diffusion and transfer of guest molecules, and powdered form .…”