Challenges in fabrication of mesoporous carbon films with ordered cylindrical pores via phenolic oligomer self-assembly with triblock copolymers
Citation
Song, L.; Feng, D.; Fredin, N.J.;Yager, K.G.; Jones, R.L.; Wu, Q.; Zhao, D.; Vogt, B.D. "Challenges in fabrication of mesoporous carbon films with ordered cylindrical pores via phenolic oligomer self-assembly with triblock copolymers"
ACS Nano 2010,
1 189–198.
doi: 10.1021/nn9012884Summary
The ordering of mesoporous films made of polymer resin and carbon were studied in detail.
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.
