Interfacial Rheology and Structure of Tiled Graphene Oxide Sheets

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• 作者：Luna Imperiali ; Ken-Hsuan Liao ; Christian Clasen ; Jan Fransaer ; Christopher W. Macosko ; Jan Vermant
• 刊名：Langmuir
• 出版年：2012
• 出版时间：May 29, 2012
• 年：2012
• 卷：28
• 期：21
• 页码：7990-8000
• 全文大小：581K
• 年卷期：v.28,no.21(May 29, 2012)
• ISSN：1520-5827

文摘

The hydrophilic nature of graphene oxide sheets can be tailored by varying the carbon to oxygen ratio. Depending on this ratio, the particles can be deposited at either a water鈥揳ir or a water鈥搊il interface. Upon compression of thus-created Langmuir monolayers, the sheets cover the entire interface, assembling into a strong, compact layer of tiled graphene oxide sheets. With further compression, the particle layer forms wrinkles that are reversible upon expansion, resembling the behavior of an elastic membrane. In the present work, we investigate under which conditions the structure and properties of the interfacial layer are such that free-standing films can be obtained. The interfacial rheological properties of these films are investigated using both compressional experiments and shear rheometry. The role of surface rheology in potential applications of such tiled films is explored. The rheological properties are shown to be responsible for the efficiency of such layers in stabilizing water鈥搊il emulsions. Moreover, because of the mechanical integrity, large-area monolayers can be deposited by, for example, Langmuir鈥揃lodgett techniques using aqueous subphases. These films can be turned into transparent conductive films upon subsequent chemical reduction.