Nonlinear spectroscopy - RB - TU Dortmund

Location & approach

By car

The campus of the Technical University of Dortmund is located near the freeway junction Dortmund West, where the Sauerland line A45 crosses the Ruhr expressway B1/A40. The Dortmund-Eichlinghofen exit on the A45 leads to the South Campus, the Dortmund-Dorstfeld exit on the A40 leads to the North Campus. The university is signposted at both exits.

By bus and train

The "Dortmund Universität" S-Bahn station is located directly on the North Campus. From there, the S-Bahn line S1 runs every 15 or 30 minutes to Dortmund main station and in the opposite direction to Düsseldorf main station via Bochum, Essen and Duisburg. In addition, the university can be reached by bus lines 445, 447 and 462. Timetable information can be found on the homepage of the Rhine-Ruhr Transport Association, and DSW21 also offer an interactive route network map.

The H-Bahn

One of the landmarks of the TU Dortmund is the H-Bahn. Line 1 runs every 10 minutes between Dortmund Eichlinghofen and the Technology Center via Campus South and Dortmund University S, while Line 2 commutes every 5 minutes between Campus North and Campus South. It covers this distance in two minutes.

By plane

From Dortmund Airport, the AirportExpress takes just over 20 minutes to Dortmund's main train station, and from there, the S-Bahn takes you to the university. A wider range of international flight connections is offered by Düsseldorf Airport, about 60 kilometers away, which can be reached directly by S-Bahn from the university's train station.

Plan of site & interactive map

The facilities of TU Dortmund University are spread over two campuses, the larger Campus North and the smaller Campus South. Additionally, some areas of the university are located in the adjacent "Technologiepark".

> Go to interactive map

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Location & approach

By car

The campus of the Technical University of Dortmund is located near the freeway junction Dortmund West, where the Sauerland line A45 crosses the Ruhr expressway B1/A40. The Dortmund-Eichlinghofen exit on the A45 leads to the South Campus, the Dortmund-Dorstfeld exit on the A40 leads to the North Campus. The university is signposted at both exits.

By bus and train

The "Dortmund Universität" S-Bahn station is located directly on the North Campus. From there, the S-Bahn line S1 runs every 15 or 30 minutes to Dortmund main station and in the opposite direction to Düsseldorf main station via Bochum, Essen and Duisburg. In addition, the university can be reached by bus lines 445, 447 and 462. Timetable information can be found on the homepage of the Rhine-Ruhr Transport Association, and DSW21 also offer an interactive route network map.

The H-Bahn

One of the landmarks of the TU Dortmund is the H-Bahn. Line 1 runs every 10 minutes between Dortmund Eichlinghofen and the Technology Center via Campus South and Dortmund University S, while Line 2 commutes every 5 minutes between Campus North and Campus South. It covers this distance in two minutes.

By plane

From Dortmund Airport, the AirportExpress takes just over 20 minutes to Dortmund's main train station, and from there, the S-Bahn takes you to the university. A wider range of international flight connections is offered by Düsseldorf Airport, about 60 kilometers away, which can be reached directly by S-Bahn from the university's train station.

Plan of site & interactive map

The facilities of TU Dortmund University are spread over two campuses, the larger Campus North and the smaller Campus South. Additionally, some areas of the university are located in the adjacent "Technologiepark".

> Go to interactive map

ServicePortal UniMail

Nonlinear rheological and dielectric spectroscopy

When materials are subjected to large external disturbances, their response is no longer proportional to the disturbance. Rather, nonlinear components contribute in addition to the linear response. Large mechanical and electrical stresses occur in the manufacture and use of everyday objects. For example, rechargeable batteries should withstand shocks, as well as the high electric fields that occur due to miniaturization.
We are investigating the nonlinear mechanical response of a wide variety of materials using large amplitude shear rheology and the electrical response using dielectric spectroscopy with high electric field strengths. These nonlinear responses can reveal new behaviors not present in the linear domain as well as provide information about processes already occurring linearly.

For example, the nonlinear shear rheological response of the monoalcohol 4-methyl-4-heptanol (4M4H) in the plot on the right shows a low-frequency Debye process, corresponding to fluctuations of transient hydrogen bonded chains (see here), which is already implied in the linear response of the shear modulus G.

Articles on "Nonlinear spectroscopy".

Linear and nonlinear 4M4H rheology spectra. The storage and loss moduli G' and G'' of 4M4H are plotted as a function of frequency at the temperature 180 K. Also shown are the nonlinearity parameters 1Q0 and 3Q0 at the same temperature as a function of frequency. A process which is slower than the alpha process and is slightly implied but difficult to detect in the linear response is reflected much more strongly in the nonlinearity parameters, allowing for an unequivocal identification of this process.