Electric‐Field‐Driven Assembly of Oriented Molecular‐Sieve Films

Macroscopically Oriented Porous Materials with Periodic Ordered Structures: From Zeolites and Metal–Organic Frameworks to Liquid‐Crystal‐Templated Mesoporous Materials

“…Although the mechanisms of magnetic and electric orientation are analogous to one another, these two methods are different in the following aspects and, consequently, they can play complementary roles in practical situations. 1) Experimental setup : For electric orientation, an easily available experimental setup is effective for a wide range of materials . In the case of magnetic orientation, the required setup depends on the magnetic properties of the target material.…”

“…For paramagnetic materials, even a hand‐held magnet can be effective, whereas for diamagnetic materials, a superconducting magnet is generally required 2) Prediction of orientation direction : When the structure of the target nano‐object is known, the results of electric orientation, in terms of efficiency and preferred direction, can be predicted more easily than those of magnetic orientation 3) Operational convenience and sample shape : Unlike magnetic fields, electric fields can be applied only through contact with the target samples.…”

“…Before the polarized absorption measurement, a chromophore ((4‐nitrophenyl)amine) was incorporated in the channels of AlPO 4 ‐5. Reproduced with permission . Copyright 2004, Wiley‐VCH.…”

“…Later, Yates and co‐workers reported that an electric field could be used to induce in‐plane orientation of large rod‐shaped crystals of AlPO 4 ‐5 on glass substrates. AlPO 4 ‐5 fibers dispersed in an organic solvent were repeatedly deposited on substrates in the presence of a dc electric field (10 kV cm −1 ) applied in the direction parallel to the substrate surface (Figure bii) . By using (4‐nitrophenyl)amine‐doped AlPO 4 ‐fibers, the corresponding oriented film was also formed.…”

“…This progress report presents an overview of recent studies on the synthesis, properties, and applications of porous materials with macroscopically oriented structures ( Table 1 ). The scope of this report is limited to porous materials with nano‐ or mesoscale periodic channels constructed by supramolecular self‐assembly of atomic and/or molecular components, such as zeolites (Section ), MOFs (Section ), mesoporous oxides (Section ), and polymers based on liquid crystals (LCs) (Section ) . In other words, porous materials produced by physical processes, such as anodic aluminum oxides or porous silicones, are beyond the scope of this report.…”