Microphase Separation of Cationic Homopolymers Bearing Alkyl Ammonium Salts into Sub-4 nm Lamellar Materials with Water Intercalation Channels

Order-Order Transition in Statistical Copolymer Thin Film Induced by LCST-Type Behavior

“…We have also reported that the hydration of comb-shaped polymers enhances nanophase separation forces. ,,− This increase is due to water adsorbed onto hydrophilic groups such as amides, esters, and carboxyls, enhancing their hydrophilicity. Terashima and co-workers further reported that the lamellar structure in poly(alkyl acrylate)s with cationic side chains becomes more uniform with hydration . Therefore, in this paper, we explore the self-assembled structure of p(ODA50/HEAm50) under hydrated conditions.…”

Universal Access to Water-Compatible and Nanostructured Materials via the Self-Assembly of Cationic Alternating Copolymers

“…Thus, the position of absorbed water in the lamellar structure was evaluated by neutron reflectivity (NR) measurement of the Alt-C12b thin film spin-coated on a silicon wafer (Figure ). The dry sample (annealed at 80 °C before measurement) showed a sharp Bragg peak at q = 2.08 nm –1 , Kiessig fringes, and a total reflection at q < 0.1 nm –1 in dry air at 30 °C and formed a multilayered lamellar structure with 3.02 nm domain spacing.…”

“…Taking advantage of water, biological systems induce self-assembly of amphiphilic biomolecules to form well-defined nanostructures and tissues . From this perspective, water-assisted self-assembly of amphiphilic (macro)­molecules is promising to create not only materials containing a large amount of water, such as hydrogels, but also functional materials with water-compatible nanostructures, because the morphologies and size could be tuned by absorbing water from the surroundings − and the hydrophilic domains may serve as the channels of water and ions for applications. , …”

“…Generally, nanostructured materials are obtained from the self-assembly or microphase separation of (co)­polymers, supramolecules, and related compounds. − As a strategy alternative to sub-10 nm microphase separation of block copolymers, − self-assembly of the side or graft chains of random, alternating, and brush (co)­polymers − ,− has attracted attention to make nanostructures with 10 nm or less domain spacing into materials. For example, random or related copolymers bearing hydrophilic side chains such as poly­(ethylene glycol) and quaternary ammonium cations and hydrophobic alkyl groups form lamellar structures via the association of their side chains in the bulk state and thin films. ,,− The domain spacing is in the range between 3 and 6 nm and controllable at the 0.1 nm level by tuning the side chains or copolymer composition. However, on-demand control of sub-10 nm morphologies, including lamella, gyroid, and cylinder, has hardly been achieved yet via the pendant self-assembly of (co)­polymers.…”

“…Thermal or water-vapor annealing is effective at promoting the microphase separation of copolymers with polar functional groups. − First, two Alt-C8 samples were prepared: one is thermally annealed and dried at 80 °C in vacuo for 2 h, and the other is annealed with water vapor in 90% relative humidity (RH) at 30 °C for 24 h (using a constant temperature and humidity chamber). The polymer samples were sealed with PEEK films and analyzed by small-angle X-ray scattering (SAXS) at 25 °C.…”