CALM TALK 77 | Functional Hybrid Materials Based on Colloidal particles

主题:   Functional Hybrid Materials Based on Colloidal particles主讲人:   陆琰 博士地点:   亿万先生mr01官网 先进低维材料中心学术交流室(2号学院楼西2632)时间:   2018-11-01 14:00:00组织单位:   先进低维材料中心

报告人简介:

Yan Lu studied chemistry at Donghua University (China) in 1994. She received her MSc from Donghua University in 2001. In 2005, she received her PhD withsumma cum laude under the supervision of Prof. H.-J. P. Adler in macromolecular chemistry at the Dresden University of Technology. She received “APi-Prize” as the best dissertation in 2005 by the German Chemical Society (GDCh) Division of Coatings and Pigments. After that, she worked first as post-doctor then research scientist in Prof. M. Ballauff’s group at the University of Bayreuth. Since 2009, she joined the Helmholtz-Zentrum Berlin für Materialien und Energie as a group leader in Colloid Chemistry. She received“Dr. Hermann-Schnell-Stipendium” by the German Chemical Society (GDCh) 1n 2011.From 2011-2013, she was selected in Helmholtz-Akademie and finished with success. She was selected as top female researchers (W2/W3-Programme) in Helmholtz Association in 2015. Since 2017, she is professor in the Institute of Chemistry at the University of Potsdam.


报告摘要:

We present the synthesis, characterization and possible applications of metallicnanoparticles immobilized in different colloidal carrier system, namely in i) spherical polyelectrolyte brushes (SPB) and ii) core-shell microgels.The polymeric carriers ensure the stability of metal nanoparticles against aggregation without impeding their catalytic activity which is measured in aqueous suspension. We first present work done on facetted metal nanocrystals fabricated on cationic spherical polyelectrolyte brushes. The catalytic reduction of 4-nitrophenol (Nip) to 4-aminophenol using sodium borohydride as reducing agent is presented as model reaction for the catalytic studies of these systems in water.

Thermosensitive core-shell microgel particles, in which the core consists of polystyrene whereas the shell consists of a poly (N-isopropylacrylamide) (PNIPA) network, have been used as “nanoreactors” for the deposition of metal nanoparticles (such as Ag, Au, Pd, and Pt). We demonstrate that the catalytic activity of the metal nanoparticles can be tuned by the volume transition within the microgel by using the catalytic reduction of 4-nitrophenol as the model reaction. In addition, Cu2O@PNIPA core-shell nanoreactors have been synthesized using Cu2O nanocubes as the core. The PNIPA shell not only protects the Cu2O nanocubes from oxidation, but also improves the colloidal stability of the system. The Cu2O@PNIPA core-shell microgels can work efficiently as photocatalyst for the decomposition of methyl orange under visible light. A significant enhancement in the catalytic activity has been observed for the core-shell microgels compared with the pure Cu2O nanocubes. Most importantly, the photocatalytic activity of the Cu2O nanocubes can be further tuned by the thermosensitive PNIPA shell. A theory for the diffusion- and solvation-controlled contribution to the reaction rate of such a “nanoreactor” has been also discussed. Hence, the microgel particles present an “active” carrier system for applications in catalysis.

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撰写:张妮