Berlin 2018 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 32: Poster Session II
CPP 32.13: Poster
Dienstag, 13. März 2018, 14:00–16:00, Poster B
Optical properties of FePt-nanoparticle loaded microgels — •Alexander Nedilko1, Katharina Wiemer2, Ulrich Simon2, and Gero von Plessen1 — 1Inst. of Physics (IA), RWTH Aachen — 2Inst. of Inorganic Chemistry, RWTH Aachen
Microgels are polymer networks of micrometer or submicrometer dimensions. Suspended in a liquid, e.g., water, microgels are sensitive to ambient conditions such as temperature or pH. Good biocompatibility makes the microgels particularly interesting due to their potential use for the controlled delivery of drugs or in biotechnology. By loading the microgels with iron-platinum nanoparticles (FePt NPs), which are good absorbers of light in the UV-vis spectral range, it is possible to create hybrid materials with interesting optical properties. The volume phase transition (VPT) of the microgels can be triggered by thermal and photothermal heating. We investigate the optical properties of FePt-NP loaded poly(N-vinylcaprolactam)-based microgels during the volume phase transition. For this purpose, we use an integrating sphere to separate from each other the parts of the incident light that are absorbed and scattered by the hybrid structures. The measurements show that the scattered part experiences a pronounced increase during the VPT of the microgel whereas the absorbed part remains almost at the initial value. The increase of the scattered part is caused by a change in the refractive index of the microgel material that results from the VPT.