Controlled Two-Dimensional Alignment of Metal–Organic Frameworks in Polymer Films

Abstract

Controlling the alignment of metal−organic framework (MOF) particles is valueable for fully exploiting the anisotropic properties and porous structure of these materials. Herein, we propose a simple, one-step method that can control the two-dimensional (2D) alignment of MOF particles over large areas. Orientational control is achieved without consideration of the underlying lattice parameters or the need for particle surface modification, but instead was achieved by selection of the casting solvent on a water surface. Two distinct types of MOF particles, a hexagonal bifrustum morphology of MIL-96 and an octahedral morphology of the UiO-66 family were aligned and captured in a polydimethylsiloxane (PDMS) matrix using this approach. This work provides opportunities for studying and utilizing the anisotropic properties of MOFs in thin film applications.

Recent advances in nanoarchitectures of monocrystalline coordination polymers through confined assembly

“…However, even in this case, voids still could not be avoided. Monocrystalline coordination polymers were also dispersed in a solvent containing a polydimethylsiloxane ( Figure 7b ) [ 139 ]. The mixed solution was cast at liquid–liquid or air–liquid interfaces.…”

Oriented self-assembly of metal–organic frameworks driven by photoinitiated monomer polymerization

“…43,44 Very recently, they proposed a novel method to control the 2D alignment of MOF polyhedral particles in polydimethylsiloxane (PDMS) lms, which was achieved by casting different solvents, including a dispersed MOF and heat-curable PDMS, to immobilize the MOF particles at the water-liquid interface. 45 Although this work is inspiring and encouraging, heat as the reaction condition is relatively single and limited. By comparison, light as a stimulus resource has some unique advantages, such as high spatial and temporal resolution, variable tunable parameters, and different light sources.…”

Thin Film Growth of 3D Sr‐based Metal‐Organic Framework on Conductive Glass via Electrochemical Deposition

“…[ 12 , 13 , 14 , 15 , 16 , 17 ] These reported methods are only successful for the deposition of MOFs on specific type of surface‐modified and non‐conducting substrates. [ 18 , 19 , 20 ] To utilize MOFs in optoelectronic and microelectronic circuits, it is usually necessary to grow MOFs on conducting substrate such as transparent conducting oxide (TCO), F‐doped SnO 2 or Sn‐doped In 2 O 3 (ITO), Cu, and carbon surfaces. Researchers have developed serval techniques which demonstrated electrochemical deposition of various conducting materials into porous MOFs thin films, fabricated on conductive substrates.…”

“…Due to the wide variety of applicative measures of thin film of MOFs, different deposition methodologies are employed when different kinds of substrates are being used such as alumina, silicon wafers, Ag/Au nanosheets, copper foil, and glass slides [12–17] . These reported methods are only successful for the deposition of MOFs on specific type of surface‐modified and non‐conducting substrates [18–20] . To utilize MOFs in optoelectronic and microelectronic circuits, it is usually necessary to grow MOFs on conducting substrate such as transparent conducting oxide (TCO), F‐doped SnO 2 or Sn‐doped In 2 O 3 (ITO), Cu, and carbon surfaces.…”