title: Challenges in fabrication of mesoporous carbon films with ordered cylindrical pores via phenolic oligomer self-assembly with triblock copolymers.
abstract: Mesoporous phenol formaldehyde (PF) polymer resin and carbon films are prepared by a solution self-assembly of PF oligomers with amphiphilic triblock copolymers. After thermopolymerization of the PF to cross-link the network, the films show an ordered morphology as determined by X-ray diffraction and grazing incidence small-angle X-ray scattering (GISAXS). Our results show that the amphiphilic triblock copolymer template greatly influences the stability of the final porous mesostructures. The pyrolysis of the two-dimensional (2-D) hexagonal films with p6mm symmetry templated by Pluronic F127 yields a disordered porous structure following the template removal. Conversely, films templated by Pluronic P123 can exhibit well-ordered cylindrical pores after the template removal, but the solution composition range to yield ordered cylindrical mesopores is significantly reduced (nearly 70%) for thin films in comparison to bulk powders. We propose two dominant difficulties in fabricating well-ordered cylindrical mesopores in films: first, the stress from contraction during the pyrolysis can lead to a collapse of the mesostructure if the wall thickness is insufficient, and second, the surface wetting behavior in thin films leads to a small compositional range.
authors.affiliation: Chemical Engineering Program, Arizona State University, Tempe, Arizona 85287, USA.
authors.forename: Lingyan
authors.initials: L
authors.lastname: Song
authors.forename: Dan
authors.initials: D
authors.lastname: Feng
authors.forename: Nathaniel J
authors.initials: NJ
authors.lastname: Fredin
authors.forename: Kevin G
authors.initials: KG
authors.lastname: Yager
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Jones
authors.forename: Quanyan
authors.initials: Q
authors.lastname: Wu
authors.forename: Dongyuan
authors.initials: D
authors.lastname: Zhao
authors.forename: Bryan D
authors.initials: BD
authors.lastname: Vogt