Cellulose nanofibers decorated with magnetic nanoparticles: synthesis, structure and use in magnetized high toughness membranes for a prototype loudspeaker
2013 (English)In: Journal of Materials Chemistry C, ISSN 2050-7526, Vol. 1, no 47, 7963-7972 p.Article in journal (Refereed) Published
Magnetic nanoparticles are the functional component for magnetic membranes, but they are difficult to disperse and process into tough membranes. Here, cellulose nanofibers are decorated with magnetic ferrite nanoparticles formed in situ which ensures a uniform particle distribution, thereby avoiding the traditional mixing stage with the potential risk of particle agglomeration. The attachment of the particles to the nanofibrils is achieved via aqueous in situ hydrolysis of metal precursors onto the fibrils at temperatures below 100 °C. Metal adsorption and precursor quantification were carried out using Induction Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). FE-SEM was used for high resolution characterization of the decorated nanofibers and hybrid membranes, and TEM was used for nanoparticle size distribution studies. The decorated nanofibers form a hydrocolloid. Large (200 mm diameter) hybrid cellulose/ferrite membranes were prepared by simple filtration and drying of the colloidal suspension. The low-density, flexible and permanently magnetized membranes contain as much as 60 wt% uniformly dispersed nanoparticles (thermogravimetric analysis data). Hysteresis magnetization was measured by a Vibrating Sample Magnetometer; the inorganic phase was characterized by XRD. Membrane mechanical properties were measured in uniaxial tension. An ultrathin prototype loudspeaker was made and its acoustic performance in terms of output sound pressure was characterized. A full spectrum of audible frequencies was resolved.
Place, publisher, year, edition, pages
2013. Vol. 1, no 47, 7963-7972 p.
Nanocomposite, Magnetic nanoparticle, Cellulose nanofiber, Mechanical properties, Acoustic
Paper, Pulp and Fiber Technology
IdentifiersURN: urn:nbn:se:kth:diva-133562DOI: 10.1039/C3TC31748JISI: 000327259700024ScopusID: 2-s2.0-84887944251OAI: oai:DiVA.org:kth-133562DiVA: diva2:662123
FunderKnut and Alice Wallenberg Foundation
QC 201312202013-11-062013-11-062013-12-20Bibliographically approved