Author: JAGS

Elisa Carenza defended her PhD Thesis on the 11th of July,  the jury formed by

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.

Multiferroic Iron Oxide Thin Films at Room Temperature
Martí Gich ,* Ignasi Fina , Alessio Morelli , Florencio Sánchez , Marin Alexe ,
Jaume Gàzquez , Josep Fontcuberta , and Anna Roig

Advanced Materials Volume 26, Issue 27, pages 4645–4652, July 16, 2014, DOI: 10.1002/adma.201400990

Multiferroic behaviour at room temperature is demonstrated in ε-Fe₂O₃. The simple composition of this new ferromagnetic ferroelectric oxide and the discovery of a robust path for its thin film growth by using suitable seed layers may boost the exploitation of ε-Fe₂O₃ in novel devices.

Enhanced stability of superparamagnetic iron oxide nanoparticles in biological media using a pH adjusted-BSA adsorption protocol
Si-Ming Yu • Anna Laromaine* • Anna Roig*
J Nanopart Res (2014) 16:2484, DOI 10.1007/s11051-014-2484-1

SPIONs were  synthesized by  a facile, rapid  and cost  effective  microwave  assisted  method. Then,  a modified pH  adjusted-BSA  adsorption  protocol and an  addition of excess  trisodium citrate dihydrate (Na₃Cit) were used to enhance their stability in the media. The BSA adsorption protocol showed great efficiency in stabilizing the dispersed state of both SPIONs in the tested media, while the addition of excess Na₃Cit showed limit effect. The formed BSA layer on SPIONs could be imaged by negative staining TEM, and revealed by Cryo-TEM, FTIR, DLS and the zeta potential measurements. Results indicated that BSA forms a monolayer of a thickness of about 3 ± 1 nm and BSA interacts with SPIONs coating rather than by replacing them and interacting directly with the SPIONs surface. This synthetic method and stabilization protocol offer a general methodology to obtain SPIONs with a variety of surfactants, stable in different biological media in few minutes.

The scientific review panel of the Council for the Lindau Nobel Laureate Meetings has selected Laura to participate in the 64 th Lindau Nobel Laureate Meeting, to be held from 29 June to 4 July 2014, in Lindau, Germany. Only the 600 most qualified young researchers can be given the opportunity to enrich and share the unique atmosphere of the Lindau Nobel Laureate Meeting

http://www.lindau-nobel.org/2014_Lindau_Meeting__Physiology_Medicine.AxCMS?ActiveID=2782

Victor Fuentes, Olga Muntada and Isable Hausmann will be undertaking their final year research project in our group. They will be supervised by Anna Roig, Maria Milla and Anna Laromaine. Here they are receiving a tutorial on nanoparticle synthesis by Siming Yu who is doing an excellent training. Thanks Siming!