Impact of Film Thickness on the Morphology of Mesoporous Carbon Films Using Organic鈭扥rganic Self-Assembly

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• 作者：Bryan D. Vogt ; Vicki L. Chavez ; Mingzhi Dai ; M. Regina Croda Arreola ; Lingyan Song ; Dan Feng ; Dongyuan Zhao ; Ginusha M. Perera ; Gila E. Stein
• 刊名：Langmuir
• 出版年：2011
• 出版时间：May 3, 2011
• 年：2011
• 卷：27
• 期：9
• 页码：5607-5615
• 全文大小：1081K
• 年卷期：v.27,no.9(May 3, 2011)
• ISSN：1520-5827

文摘

Mesoporous polymer and carbon thin films are prepared by the organic鈭抩rganic self-assembly of an oligomeric phenolic resin with an amphiphilic triblock copolymer template, Pluronic F127. The ratio of resin to template is selected such that a body-centered cubic (Im3m) mesostructure is formed in the bulk. However, well-ordered mesoporous films are not always obtained for thin films (<100 nm), and this behavior is found to be directly correlated with the initial phenolic resin to template ratio. Furthermore, the symmetry of ordered phases is highly dependent on the number of layers of spheres in the film: Monolayers and bilayers are characterized by hexagonal close-packed (HCP) symmetry, while films with approximately 5 layers of spheres exhibit a mixture of HCP and face-centered orthorhombic (FCO) structures. Ultrathick films having more than 30 layers of spheres are similar to the bulk body-centered cubic symmetry with a preferential orientation of the closest-packed (110) plane parallel to the substrate. Film thickness and initial composition of the carbonizable precursors in the template are critical factors in determining the morphology of mesoporous carbon films. These results provide insight into why difficulties have been reported in producing ultrathin ordered mesoporous carbon films using cooperative organic鈭抩rganic self-assembly.