TY  - JOUR
A1  - Lützow, Karola
A1  - Weigel, Thomas
A1  - Lendlein, Andreas
T1  - Solvent-based fabrication method for magnetic, shape-memory nanocomposite foams
JF  - MRS advances
N2  - This paper presents shape-memory foams that can be temporarily fixed in their compressed state and be expanded on demand. Highly porous, nanocomposite foams were prepared from a solution of polyetherurethane with suspended nanoparticles (mean aggregate size 90 nm) which have an iron(III) oxide core with a silica shell. The polymer solution with suspended nanoparticles was cooled down to -20 degrees C in a two-stage process, which was followed by freeze-drying. The average pore size increases with decreasing concentration of nanoparticles from 158 mu m to 230 mu m while the foam porosity remained constant. After fixation of a temporary form of the nanocomposite foams, shape recovery can be triggered either by heat or by exposure to an alternating magnetic field. Compressed foams showed a recovery rate of up to 76 +/- 4% in a thermochamber at 80 degrees C, and a slightly lower recovery rate of up to 65 +/- 4% in a magnetic field.
KW  - composite
KW  - foam
KW  - polymer
KW  - magnetic
KW  - shape memory
Y1  - 2020
U6  - https://doi.org/10.1557/adv.2019.422
SN  - 2059-8521
VL  - 5
IS  - 14-15
SP  - 785
EP  - 795
PB  - Cambridge Univ. Press
CY  - Cambridge
ER  -