Regensburg 2016 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 25: Focus: Functional Polymer Hybrids II

CPP 25.2: Vortrag

Dienstag, 8. März 2016, 14:30–14:45, H51

Gold nanoparticles as local hot spots in thermoresponsive microgels — •Maren Lehmann, Weronika Nasiłowska, Tim Möller, Stefan Wellert, and Regine von Klitzing — Applied Physical Chemistry, TU Berlin, Berlin, Germany

Sensoric ultrathin coatings have a high impact in basic research and for technical applications. A promising combination is of metal particles embedded in a polymer matrix. The metal particles can interact with external fields (e.g. light, magnetic field) and the polymer matrix can be sensitive to outer stimuli like temperature, pH or ionic strength. Here, we present a hybrid system of thermosensitive poly(N-isopropylacrylamide) (PNIPAM, LCST: 32°C) microgels and Au nanoparticles (Au NP). The incorporation of Au NP into the PNIPAM microgel influences the optical properties of the microgels via plasmon coupling during their volume phase transition [1] [2]. In order to study the effect of hot spots, we coupled a second laser for plasmon excitation into our dynamic light scattering (DLS) set-up. The loading density of the Au NP within the microgels was optimized for our purpose. The plasmon excitation of Au NP results in local heating providing enough heat to induce a reduction in the microgel size. Depending on the uptake of Au NP the induced size change also varies and the apparent internal temperature within the gel can be determined.

1. Lange, H. et al. Langmuir, 2012, 28, 8862

2. Gawlitza, K. et al. Phys. Chem. Chem.Phys., 2013, 15, 15623