Preparation of Honeycomb-Patterned Polyimide Films by Self-Organization

Abstract

Microporous polymer films are attractive materials with potential application in the fields of electronics, photonics, and biotechnology. Chemical and thermal stabilities of the microporous polymer films are required for their materials application. Besides preparation by conventional photolithography, we have reported that honeycomb-patterned porous polymer films are prepared by a method utilizing the condensation of small water droplets on solutions of amphiphilic copolymers. Here, we show preparation of honeycomb-patterned microporous films of a thermally and chemically stable material, polyimide. A water-template-assisted honeycomb structure was formed from a polyion complex of polyamic acids and dialkylammonium salt. The pore size of films was controlled by the casting volume of polymer solution. The patterned polyion complex film converted into polyimide by simple chemical treatment, keeping the porous structure. Self-supporting microporous polyimide films are fabricated. The honeycomb-structured film has high thermal and chemical stability like that of conventional cast films of polyimides.

Mesoscopic Patterning in Thin Polymer Films Formed under the Fast Dip‐Coating Process

“…Thin polymer films were obtained under drying of the polymer solution falling vertically along a metal, glass or polymer substrate. Mesoscopic patterning of the evaporated polymer films was observed by various groups and studied very thoroughly recently [6][7][8][9][10][11] . At the same time, the mechanism of the evaporation-induced mesoscopic self-assembly is still not clearly understood.…”

“…Srinivasarao, Shimomura and Pitois have related the phenomenon to atmospheric humidity, which can favor the formation of the honeycomb films [8][9][10][12][13][14] . L. Weh related self-organization to mass and heat transfer processes, which take place in the thin polymer film under the dewetting procedure.…”

Breath-Figures Self-Assembly, the Versatile Method of Manufacturing Membranes and Porous Structures: Physical, Chemical and Technological Aspects

“…Breath-figures inspired topographies may be obtained with thermoplastic [14, 15, 16, 37-38, 41, 44-46, 61-62] and thermosetting [50][51][52] polymers. High-performance engineering polymers, such as polyimide [53], polyetherimide [54] and polysulfone [45,55] were successfully used for the breath-figures self-assembly. 2D and 3D hierarchical structures, possessing a range of scales from micro-meters to nano-meters were reported [14,35,150].…”

“…Breath-figures self-assembly has been carried out with thermoplastic [14,15,16,41,[44][45][46] and crosslinked polymers [50][51][52]. Several groups reported breath-figures patterns obtained with high performance, engineering polymers, such as polyimide [53], polyetherimide [54], polysulfone [45,55] and siliconcontaining graft copolymer poly(dimethylsiloxane)-graft-polyacrylates (PDMS-g-PAs) [56].…”

Thermally-Driven Nanoparticle Array Growth from Atomic Au Precursor Solutions

“…One possible mechanism for array formation involves the Bénard-Marangoni effect, wherein a thin fluid layer heated from below supports formation of stable spatial convection patterns when the liquid temperature gradient exceeds a critical value. [29][30][31][32] Although the effect has been shown to form micrometer-sized hexagonal morphologies in thin polymer films, [33][34][35] it is unclear if the effect can extend to the present size regime (∼10 nm lattice constant). [36][37][38] At present, our results are not sufficiently restrictive to prove that nonequilibrium fluid flow dynamics alone can give rise to the aforementioned mechanism of lattice point and lattice symmetry formation followed by in situ nanoparticle formation.…”