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Investigators at University of Utrecht Detail Findings in Nanoparticles

May 27, 2014

By a News Reporter-Staff News Editor at Physics Week -- Investigators publish new report on Nanoparticles. According to news originating from Utrecht, Netherlands, by VerticalNews correspondents, research stated, "The permanent electrical, dipole moment of colloidal quantum dots is important for their optoelectronic properties and can be determined by dielectric spectroscopy. Until now, however, colloidal interactions have not been taken into account in the interpretation of the spectra."

Our news journalists obtained a quote from the research from the University of Utrecht, "Here, dielectric spectra of PbSe and CdSe colloidal quantum dots dispersed in an apolar liquid are measured from 1 Hz to 10 MHz. At frequencies of 10 kHz-1 MHz, Brownian rotation of nanoparticles with a permanent electric dipole moment is detected. At the lowest concentrations (similar to 0.1 vol %), the nanoparticles rotate independently of each other, and their dipole moment, for both PbSe and CdSe, is on the order of 40-50 D. At higher concentrations (>= 0.3 vol %), the dipolar relaxation becomes slower, indicating the presence of nanoparticle structures. A simple model is used to estimate the interaction strength, which appears to be stronger than expected from the weak dipole moment, and has possibly also contributions from electrical moments of higher order."

According to the news editors, the research concluded: "Our results indicate that nanoparticle interactions in liquid media lead to small equilibrium structures that affect dielectric measurements of the dipole moment already at concentrations of a few tenths of a volume percent."

For more information on this research see: Equilibrium Structures of PbSe and CdSe Colloidal Quantum Dots Detected by Dielectric Spectroscopy. Journal of Physical Chemistry C, 2014;118(13):7185-7194. Journal of Physical Chemistry C can be contacted at: Amer Chemical Soc, 1155 16TH St, NW, Washington, DC 20036, USA. (American Chemical Society -; Journal of Physical Chemistry C -

The news correspondents report that additional information may be obtained from R.J. Kortschot, University of Utrecht, Debye Inst Nanomat Sci, NL-3584 CH Utrecht, Netherlands. Additional authors for this research include J. van Rijssel, R.J.A. van Dijk-Moes and B.H. Erne.

Keywords for this news article include: Europe, Utrecht, Netherlands, Quantum Dots, Nanotechnology, Quantum Physics, Emerging Technologies

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Source: Physics Week

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