Preparation and Characterization of Nanofibrous Perylene-Diimide-Polyelectrolyte Composite Thin Films
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- 作者：Thomas A. Everett ; Amy A. Twite ; Aifang Xie ; Srinivas K. Battina ; Duy H. Hua ; Daniel A. Higgins
- 刊名：Chemistry of Materials
- 出版年：2006
- 出版时间：December 12, 2006
- 年：2006
- 卷：18
- 期：25
- 页码：5937 - 5943
- 全文大小：385K
- 年卷期：v.18,no.25(December 12, 2006)
- ISSN：1520-5002
文摘
Composite nanofibrous thin films of a cationic, water-soluble perylene diimide and oppositely chargedpolyelectrolyte are prepared by sequential deposition from separate aqueous solutions of the two precursors.These materials may find future applications as semiconducting "wires" in organic electronics andphotovoltaics. A new asymmetrically substituted perylene diimide (designated C11OPDI+) incorporatinga hydrophobic ether tail is employed in their synthesis. Poly(acrylate) is used as the polyelectrolyte.Solution-phase and thin-film spectroscopic data show the composites form by binding and aggregationof C11OPDI+ to the polyelectrolyte. Tapping-mode AFM data show that the resulting nanofibers are tensof micrometers in length and are highly curved. Cross-sectional fiber size is shown to depend on thenumber of deposition cycles. Polarization-dependent fluorescence microscopy indicates the C11OPDI+chromophores align perpendicular to the local long axis of the nanofibers. The C11OPDI+ molecules areconcluded to form tail-to-tail parallel 
-stacked structures that run along the fiber axis and are sandwichedbetween polyelectrolyte regions. In comparison to alternative methods, nanofiber formation is shown tobe greatly enhanced when the composite is prepared by sequential deposition. A mechanism for enhancedfiber formation involving slow growth and solvent annealing of the composites is proposed.
-stacked structures that run along the fiber axis and are sandwichedbetween polyelectrolyte regions. In comparison to alternative methods, nanofiber formation is shown tobe greatly enhanced when the composite is prepared by sequential deposition. A mechanism for enhancedfiber formation involving slow growth and solvent annealing of the composites is proposed.