The field of plasmonics fuels the formation of nanoparticle aggregates which feature novel optical and plasmonic properties. One strategy is to increase the complexity by the controlled formation of nanoparticle aggregates. In such configurations, the plasmonic coupling of the individual particles can exhibit novel properties.While a lot of research is devoted on the theoretical understanding of such nanoparticle aggregates, synthetic routes to form these materials are still relatively scarce.[1] Here, a conceivable approach is introduced, which permits the formation of PEI-Au nanoparticle superaggregates.[2] The amine functions of the PEI can bind the gold salt which is reduced at elevated temperatures to form small gold nanoparticles. During the reaction the initially soluble polymer undergoes cross-linking reactions and a stable polymer shell is formed, which encapsulates a large number of individual Au nanoparticles. The size of the superaggregates can be tuned by the control of the ratio between the PEI and the Au nanoparticles.One important parameter for the utilization of such supernanoparticle aggregates for plasmonic applications is the achievable filling factor. Different synthetic strategies to tune this filling factor include seeded-growth approaches to enlarge the nanoparticle size within the superaggregates. UV-vis spectra obtained from individual nanoparticle aggregates by darkfield microscopy are in good agreement with theoretical predictions of the optical properties of the aggregates.Next to the optical characterization different strategies to self-assemble these superparticles into ordered patterns are introduced with the aim to further tune the optical and plasmonics properties of the structures. [1]            F. Kretschmer, S. M�hlig, S. Hoeppener, A. Winter, M.D. Hager, C. Rockstuhl, T. Pertsch, U.S. Schubert, Particles Particle System Characterization 2014 , online.DOI: 10.1002/ppsc.201300309[2]            F. Kretschmer, U. Mansfeld, S. Hoeppener, M.D. Hager, U.S. Schubert, Chem. Commun. 2014 , 50, 88�90.

Supernanoparticle synthesis based on PEI-Au clusters

248th National Meeting (2014)

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