Switching of Structural Order in a Cross-Linked Polymer Triggered by the Desorption/Adsorption of Guest Molecules

Abstract

A cross-linked polymer, prepared by the in situ polymerization of a thermotropic columnar liquid crystal, was found to work as a host with a flexible framework, which was reminiscent of intercalation hosts, such as clays, graphites, and coordination polymers. The structural order of the cross-linked polymer was reversibly switched by changing the amount or shape of a guest incorporated in the polymer.

Selective Absorption of Hydrophobic Cations in Nanostructured Porous Materials from Crosslinked Hydrogen‐Bonded Columnar Liquid Crystals

“…There are several examples of porous materials made from LCs, however, only a few have been reported from hydrogenbonded LCs. [10][11][12][13][14][15][16][17][18][19][20][21] A class of LCs which is even less commonly investigated for its thermotropic LC properties is that of hydrogen-bonded discotic or columnar LCs. One example is of Ishida and co-workers , who demonstrate the template assisted self-assembly of columnar LCs via orthogonal ionic interactions.…”

“…One example is of Ishida and co-workers , who demonstrate the template assisted self-assembly of columnar LCs via orthogonal ionic interactions. [13][14][15] Similarly, a template-assisted approach has previously been applied to block copolymers by Gohy and co-workers and Russell and co-workers. [22][23][24][25][26][27][28][29][30][31] The current work focuses on the application of the thermotropic LC properties of columnar benzene-1,3,5-tricarboxamide (BTA) LCs for the development of porous materials, [ 32 ] in particular toward the development of porous materials with highly selective absorbing properties.…”

Guest‐Responsive Covalent Frameworks by the Cross‐Linking of Liquid‐Crystalline Salts: Tuning of Lattice Flexibility by the Design of Polymerizable Units

“…[12] Owing to the noncovalency of the interactions between the polymer framework and the template, the resultant polymer was capable of releasing and re-capturing certain amounts of amino alcohols. Quite interestingly, the polymer showed unexpected dynamic properties, despite of its covalently cross-linked framework; [13] in response to the adsorption/desorption of the template amino alcohol; the structure of the cross-linked polymer was reversibly transformed between rectangular columnar and amorphous states (Scheme 1c and d).…”

“…[12b] 3) The structural switching mode of the polymer was limited to only one type (rectangular columnar$amorphous), unlike the case of other supramolecular hosts, such as metal-organic frameworks. [13] Therefore, we newly employed three kinds polymerizable carboxylic acids as the matrix unit and systematically varied the polymerizable (Scheme 1, M DDD , M ANA , and M DND ). Here we report a detailed study on the properties of the resultant polymers, which revealed that the modification of the polymerizable parts had an unexpectedly large effect on their performance as solid-state hosts.…”

Self‐Assembly Made Durable: Water‐Repellent Materials Formed by Cross‐Linking Fullerene Derivatives

“…For instance, click chemistry, [2] diene metathesis, [3] and disulfide bond formation [4] have been successfully utilized to stabilize various structures such as gel fibers, self-assembled nanotubes, and host frameworks. [5] Subtle control of the reaction conditions is required to maintain the structure and morphology and to simultaneously achieve efficient covalent cross-linking, which are the key factors that determine the final performance of the supramolecular materials in practical applications.…”