Hierarchical Polyimide Microparticles with Controllable Morphology

The tunable macromolecular chain conformation of polyelectrolytes triggered by the addition of 1,2-dimethylimidazole and cetyltrimethylammonium chloride (CTAC) can greatly influence their self-assembly behavior during hydrothermal reaction (HTR). Hierarchical polyimide (PI) microparticles with controllable morphology are prepared. This work provides new insights into the construction of diverse hierarchical structures of polymer materials. AbstractHierarchical polyimides (PIs) not only show outstanding thermal stability and high mechanical strength but also have great advantages in terms of microstructure and surface area, which makes them highly valuable in various fields such as aerospace, microelectronics, adsorption, catalysis, and energy storage. However, great challenges still remain in the synthesis of hierarchical PIs with well-defined microstructure. Herein, polyamide acid salts (PAAS) with tunable ionization degree are synthesized first via the polymerization of dianhydride and diamine monomers in deionized water with 1,2-dimethylimidazole (DMIZ). Then cationic cetyltrimethylammonium chloride (CTAC) is added to the PAAS aqueous solution to induce the formation of polyelectrolyte-surfactant complexes based on electrostatic interaction. After a typical hydrothermal reaction (HTR) procedure, hierarchical PIs with different microstructures such as urchin-like PI microparticles, flower-like PI microparticles, and lamellar PI petals can be fabricated simply by changing th...
Source: Small - Category: Nanotechnology Authors: Tags: Research Article Source Type: research