TY  - JOUR
A1  - Razzaq, Muhammad Yasar
A1  - Behl, Marc
A1  - Heuchel, Matthias
A1  - Lendlein, Andreas
T1  - Matching magnetic heating and thermal actuation for sequential coupling in hybrid composites by design
JF  - Macromolecular rapid communications
N2  - Sequentially coupling two material functions requires matching the output from the first with the input of the second function. Here, magnetic heating controls thermal actuation of a hybrid composite in a challenging system environment causing an elevated level of heat loss. The concept is a hierarchical design consisting of an inner actuator of nanocomposite material, which can be remotely heated by exposure to an alternating magnetic field (AMF) and outer layers of a porous composite system with a closed pore morphology. These porous layers act as heat insulators and as barriers to the surrounding water. By exposure to the AMF, a local bulk temperature of 71 degrees C enables the magnetic actuation of the device, while the temperature of the surrounding water is kept below 50 degrees C. Interestingly, the heat loss during magnetic heating leads to an increase of the water phase (small volume) temperature. The temperature increase is able to sequentially trigger an adjacent thermal actuator attached to the actuator composite. In this way it could be demonstrated how the AMF is able to initiate two kinds of independent actuations, which might be interesting for robotics operating in aqueous environments.
KW  - artificial muscles
KW  - magnetosensitivity
KW  - nanocomposites
KW  - soft actuators
Y1  - 2019
U6  - https://doi.org/10.1002/marc.201900440
SN  - 1022-1336
SN  - 1521-3927
VL  - 41
IS  - 1
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Zou, Hua
A1  - Schlaad, Helmut
T1  - Thermoresponsive PNIPAM/Silica Nanoparticles by Direct Photopolymerization in Aqueous Media
JF  - Journal of polymer science : A, Polymer chemistry
N2  - This article presents a simple and facile method to fabricate thermoresponsive polymer-grafted silica particles by direct surface-initiated photopolymerization of N-isopropylacrylamide (NIPAM). This method is based on silica particles bearing thiol functionalities, which are transformed into thiyl radicals by irradiation with UV light to initiate the polymerization of NIPAM in aqueous media at room temperature. The photopolymerization of NIPAM could be applied to smaller thiol-functionalized particles (approximate to 48 nm) as well as to larger particles (approximate to 692 nm). Hollow poly(NIPAM) capsules could be formed after etching away the silica cores from the composite particles. It is possible to produce tailor-made composite particles or capsules for particular applications by extending this approach to other vinyl monomers. (c) 2015 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 2015, 53, 1260-1267
KW  - nanocomposites
KW  - nanoparticles
KW  - photopolymerization
KW  - silica nanoparticles
KW  - surface-initiated photopolymerization
KW  - thermoresponsive
KW  - thiol
Y1  - 2015
U6  - https://doi.org/10.1002/pola.27593
SN  - 0887-624X
SN  - 1099-0518
VL  - 53
IS  - 10
SP  - 1260
EP  - 1267
PB  - Wiley-Blackwell
CY  - Hoboken
ER  -