Regensburg 2007 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 20: POSTER: Biological Systems + New Materials
CPP 20.7: Poster
Wednesday, March 28, 2007, 16:00–18:30, Poster B
Stimuli-responsive networks containing superparamagnetic nano-particles — Xuena Zou1, •Silke Rathgeber1, and Patrick Theato2 — 1Max-Planck Institute for Polymer Research, Polymer Physics, D-55128 Mainz — 2Johannes Gutenberg-University, Institute of Organic Chemistry, D-55099 Mainz
We report the synthesis and characterization of poly(N-isopropylacrylamide) (PNiPAM) hydrogels containing superparamagnetic nano-particles which are i.a. chemically bonded to the network. Changing magnetization by swelling (humidity), pH, temperature and stress will lead to new stable stimuli-responsive materials for sensor applications but also to materials which show, in response to an external magnetic field gradient, actuatoric properties. The synthesis of the PNiPAM gel is performed via a reactive poly(pentafluorophenylacrylate) (PPFPA) precursor gel. The advantage of the presented synthesis lies in the fact that the properties, e.g. the lower critical solution temperature, of the final hydrogels can be tuned by the degree of conversion from PPFPA to PNiPAM and/or incorporation of various functional groups, e.g. pH-dependent groups. Beside standard physiochemical characterization methods we report results from cryo-transmission electron microscopy to characterize the magnetic nano-particles and their distribution in the gels. Magnetic properties of the magnetic nano-particles and the loaded hydrogels were studied using a superconducting quantum interference device. The density of the magnetic nano-particles in the hydrogels was calculated according to the response of the gels to the external field.