Pretreatment of cellulose matrix for the generation of one-dimensional nanostructures
|Urve Kallavus 1, Reet Nisumaa 1, Kairi Kriiska 1, Kalju Lott 2, Katrin Idla 3, Marek Strandberg 4|
1. Tallinn University of Technology,Centre for Materials Research (TUT), Ehitajate tee 5, Tallinn 19086, Estonia
Recently one-dimensional nanostructures based on different oxides (TiO2, ZnO) prepared through chemical precipitation, thermal evaporation under various cooling down procedures, sol-gel or other processes have been run up [1, 2]. The resulting structures are nanoparticles, nanorods, or nanolinters what are intriguing targets for different applications like semiconductors, photocatalysts etc. In this work a cellulose network as an intermediate framework to orientate producible nanostructures was used to create linter-like nanostructures. Wood cell wall structure has been self-assembled by nature in complex way forming tight fibrilar network and this structure was used as a matrix. The cellulose network plays an important role, nevertheless, after complete forming of nanostructures it must be removed. The surface of unbleached SW pulp fibres is generally rough and the fine cellulose fibril network hidden. Surface layer of detached fibres contains remnants from primary cell wall, compound middle lamella, and is highly folded due to the mass loss during pulping. To open the cellulose fine network treatment with supercritical CO2 was carried out. Depending on the duration and other parameters of this process various etching depths were obtained. Resulting structures were investigated with scanning electron microscope and atomic force microscope. Obtained fibre surfaces have highly porous structures with open network of cellulose fibrilar clusters. The depth of highly porous layer directly depends on the duration of the process. Treated in this way fibres are ready for the following introduction of precursors of one-dimensional nanostructures. Pretreatment with supercritical CO2 manifold enhances surface specific area of lignocellulosic matrix and facilitates higher reaction area.
 M.Kh. Aminian, N. Taghavinia et al, Nanotechnology 17 (2006) 520-525.
 B.H. Kong, D.C. Kim, H.K. Cho, Physica B (article in press).
Presentation: Poster at E-MRS Fall Meeting 2006, Symposium D, by Urve Kallavus
See On-line Journal of E-MRS Fall Meeting 2006
Submitted: 2006-05-15 13:47 Revised: 2009-06-07 00:44
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