Patterned Deposition of Metal-Organic Frameworks onto Plastic, Paper, and Textile Substrates by Inkjet Printing of a Precursor Solution

摘要

Metal-organic frameworks (MOFs) have attracted considerable interest because of their high surface areas, tunable pore size, and chemical versatility. These materials already have demonstrated potential for gas storage/separation, heterogeneous catalysis, drug delivery, and sensing. For their application as smart membranes, catalytic coatings, or sensing devices, the spatially and morphologically controlled growth of MOF films on various surfaces gained significant importance. In order to produce such surface-attached MOFs (so-called SURMOFs), a number of interesting methods have been developed, including direct (hydrothermal) growth, seeded growth, dip-coating, layer-by-layer growth, electrochemical deposition, gel-layer deposition, spray-coating, and evaporation/solvent induced growth. While these methods mostly yield uniform films, the precise positioning of laterally structured SURMOFs is crucial for integrated device fabrication. Several patterning techniques, such as soft lithography, pen-type lithography, photolithography, deep X-ray lithography, and electron-beam lithography, have been introduced to this area. Although such patterning techniques allow the fabrication of SURMOFs with high lateral resolution in the micro-/ nanometer regime, most of the growth methods and patterning techniques consist of complicated multistep procedures, which often require costly/complicated machinery, take long times, produce relatively large amounts of chemical waste, and are typically limited to relatively small overall areas.