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Origami magnetic cellulose: controlled magnetic fraction and patterning of flexible bacterial cellulose

Muling Zeng, Anna Laromaine,* Wenqian Feng, Pavel A. Levkin and Anna Roig*

Journal of Materials Chemistry C, (2014)  DOI: 10.1039/c4tc00787e

Cellulose of microbial origin is becoming a commodity structural material with promise in a myriad of potential applications. The range of applications can be further enlarged by nanocomposites that provide additional functional properties to the bacterial cellulose. Here, bacterial cellulose films nanocomposited with iron oxide nanoparticles are fabricated by microwave-assisted thermal decomposition within only 5 min and without the need for any post-synthetic treatment. Control over the magnetic fraction (from 4 to 40 wt%) is achieved either by employing undried cellulose, cellulose films dried by different methods, or by adjusting the initial iron precursor concentration. Structural, magnetic, and mechanical characterization of the materials is included. All films react easily to an external magnetic field, present a superparamagnetic behavior at room temperature, and are flexible enough to be bent and folded into complex origami shapes. Finally, preliminary results on a strategy to selectively pattern bacterial cellulose with nanoparticles are presented that pave the way to new uses of functional bacterial cellulose.