1. Making flexible magnetic aerogels and stiff magnetic nanopaper using cellulose nanofibrils as templates
- Author
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Ulf W. Gedde, Richard T. Olsson, Josep Nogués, Olli Ikkala, Lars Berglund, Liubov Belova, German Salazar-Alvarez, Valter Ström, Azizi Samir, Royal Institute of Technology (Sweden), Swedish Research Council, Swedish Foundation for Strategic Research, Wallenberg Wood Science Center, Knut and Alice Wallenberg Foundation, Swedish Defence Research Agency, Ministerio de Ciencia e Innovación (España), Generalitat de Catalunya, and Academy of Finland
- Subjects
Paper ,Solid-state chemistry ,Materials science ,Macromolecular Substances ,Surface Properties ,ta221 ,aerogel ,Molecular Conformation ,Biomedical Engineering ,Nanoparticle ,Bioengineering ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Nanomaterials ,Magnetics ,chemistry.chemical_compound ,Elastic Modulus ,Materials Testing ,General Materials Science ,Particle Size ,Electrical and Electronic Engineering ,Cellulose ,Porosity ,ta218 ,ta214 ,ta114 ,Aerogel ,Equipment Design ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Nanostructures ,0104 chemical sciences ,Equipment Failure Analysis ,chemistry ,Bacterial cellulose ,Magnet ,Crystallization ,0210 nano-technology - Abstract
5 páginas, 4 figuras, 1 tabla.-- et al., Nanostructured biological materials inspire the creation of materials with tunable mechanical properties. Strong cellulose nanofibrils derived from bacteria or wood, can form ductile or tough networks, that are suitable as functional materials. Here, we show that freeze-dried bacterial cellulose nanofibril aerogels can be used as templates for making lightweight porous magnetic aerogels, which can be compacted into a stiff magnetic nanopaper. The 20–70-nm-thick cellulose nanofibrils act as templates for the non-agglomerated growth of ferromagnetic cobalt ferrite nanoparticles (diameter, 40–120 nm). Unlike solvent-swollen gels and ferrogels our magnetic aerogel is dry, lightweight, porous (98%), flexible, and can be actuated by a small household magnet. Moreover, it can absorb water and release it upon compression. Owing to their flexibility, high porosity and surface area, these aerogels are expected to be useful in microfluidics devices and as electronic actuators., This work was supported by the Stiftelsen för Strategisk Forskning Center BIOMIME at KTH (Royal Institute of Technology), the Swedish Research Council, the Swedish Foundation for Strategic Research, the Wallenberg Wood Science Center, the Knut and Alice Wallenberg Foundation (Mikro/Nanovetenskap), the Swedish Defence Research Agency, the Spanish Ministerio de Ciencia e Innovación (MAT2007-66309-C02 and CSD2006-00012 Consolider-Ingenio 2010), the Catalan Direcció General de Recerca (2009-DGR-1292) and the Academy of Finland.
- Published
- 2010