BCMaterials Fortnightly Seminar #69: Iván Rodríguez & Arkaitz Fidalgo

IVÁN RODRÍGUEZ

(BCMATERIALS)

Shape Memory and Superelastic Effect at the Nanoscale

Shape memory and superelastic effect have been tested in the nanoscale, using several arrays of nanopillars shaped in Ni-Mn-Ga and Ni-Fe-(Co)-Ga FSMA single-crystalline samples. The results confirm both effects, observing on the one hand that the mechanically-induced martensitic transformation, which leads to strains up to 7%, is almost fully recoverable or superelastic. On the other hand, a strain recovery of 5% has been measured upon heating from the martensitic to the austenitic phase, showing the shape memory effect. Those characteristics provide a promising evidence for the thermal and magnetic actuation applications at the nanoscale.

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ARKAITZ FIDALGO

(BCMATERIALS)

Zn-MOF74 / Ionic Liquid composite: towards an enhance CO₂ storage capacity

Metal-organic frameworks (MOF) exhibit great potential for many applications due to their ordered structures, high surface area and pore size, tunable chemistry, high thermal stability and the availability of several well characterized structures [1]. On the other hand, Ionic Liquids (ILs) are ionic salts which have a melting point below 100 ºC and because of their wide variety of chemical and physical properties, centre the attention of many researchers. There is an increased interest in supporting ILs, and the use of MOF results in a new generation materials combining the properties of both MOF and IL [2]. The studies of MOF@IL materials are still incipient, but supported on theoretical approximations and experimental works they point out that properties of MOFs could be improved by the insertion of ILs [3]. Carbon dioxide capture and storage technology has received a worldwide attention in the last years due to the environmental impact and pronounced ecosystem change produced by CO₂. With the aim of enhancing CO₂ uptake of MOF74 material [4], on this work we studied the influence of inserting the 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate ([EmIm][OTf]) IL into Zn-MOF74 porous structure. The high pressure gas adsorption tests on Zn-MOF74@[EmIm][OTf] reveal a 15-20% of CO₂ uptake improvement with respect to the starting MOF material. [1] T. Islamoglu, S. Goswami, Z. Li, A. J. Howarth, O. K. Farhab and J. T. Hupp, Acc. Chem. Res., 50, 805 (2017). [2] K. Fujie and H. Kitagawa, Coord. Chem. Rev., 307, 382 (2016). [3] I. Cota and F. Fernandez Martinez, Coord. Chem. Rev., (2017), ahead of print. [4] N. L. Rosi, J. Kim, M. Eddaoudi, B. Chen, M. O’Keeffe and O. M. Yaghi, J. Am. Chem. Soc., 1277, 1504 (2005).