{"id":60,"date":"2021-01-27T15:53:29","date_gmt":"2021-01-27T14:53:29","guid":{"rendered":"https:\/\/blogs.urz.uni-halle.de\/sbp21\/?page_id=60"},"modified":"2023-11-15T16:25:45","modified_gmt":"2023-11-15T15:25:45","slug":"lab-courses","status":"publish","type":"page","link":"https:\/\/blogs.urz.uni-halle.de\/sbp22\/lab-courses\/","title":{"rendered":"Lab courses"},"content":{"rendered":"\n
Atomic Force Microscopy<\/h5>\n\n\n\n
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    Atomic force microscopy (AFM) is a widely employed method and can be used for force measurements, manipulation, and imaging of surfaces, with the latter being the most common application which was also the topic of this lab course. AFM utilizes a sharp tip which scans over the sample surface to acquire images. The aim of this lab course was to familiarize the students with AFM and give them practical experience in performing measurements and data analysis. In the lab course, the students first examined a calibration grating sample to optimize the feedback parameters for AFM measurements. Then the students investigated the surface of a semicrystalline polymer thin film and analysed the semicrystalline structures.<\/p>\n<\/div>\n<\/div>\n\n\n\n

    Broadband Dielectric Spectroscopy<\/strong><\/h5>\n\n\n\n
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    Broadband Dielectric Spectroscopy probes the electrical polarization of a sample in a broad spectral range from Millihertz to Megahertz. This polarization is governed by reorientation motions of polar moieties which enables to trace the dynamics of molecules, of side groups of macromolecules as well as of ions. Mapping the thermal activation of these so-called relaxation times can help to identify structure property relations of material performances ranging from charge transport to dynamics to mechanical stability. We provided a hands-on experience of such investigations on a diverse set of samples to compare among the groups.<\/p>\n<\/div>\n\n\n\n

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      Differential Scanning Calorimetry<\/h5>\n\n\n\n
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        Differential scanning calorimetry (DSC) is a standard technique used to investigate the thermal behaviour of polymers. With DSC, phase transitions of polymers and proteins can be studied and correlated to the morphology. In this lab course, the students performed DSC measurements of a typical polymer sample to determine the crystallization and glass transition parameters. Also, we demonstrated different calorimetric devices including fast scanning calorimetry (see picture) with its typical applications.<\/p>\n<\/div>\n<\/div>\n\n\n\n

        IR spectroscopy<\/h5>\n\n\n\n
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        Infrared (IR) spectroscopy is a highly versatile tool in molecular physics with multiple options for refinements, e.g. combining IR spectroscopy with Fast Scanning Calorimetry (FSC) or using grazing angle IR-reflection for interface-sensitive measurements. In this lab course, basic hands-on experiments was be provided by measuring the IR spectra of several samples. By analysing the absorption characteristics which can be understood as the “vibrational fingerprint” of a polymer, the structure of the polymeric sample can be identified. The students were invited to bring their own samples.<\/p>\n\n\n\n

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          Molecular Dynamics Simulations<\/h5>\n\n\n\n
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            Molecular Dynamics (MD) simulations are a versatile tool to model the properties of polymers, from isolated chains to solutions and melts. In principle they are simply a numerical solution to Newton\u2019s equations of motion, in practice one has to find a model of the polymer system under investigation that may either allow a quantitative prediction of structural or dynamic properties or a qualitative understanding of the behavior of a broad class of polymer systems. The lecture discussed model building as well as some technical background on the numerical approaches. The practical work studied a simple system to gain some feeling on how this approach works.<\/p>\n<\/div>\n<\/div>\n\n\n\n

            Monte Carlo Computer Simulations<\/h5>\n\n\n\n
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            Monte Carlo computer simulations are an important numerical tool for investigating polymer systems. Instead of solving Newton’s equations of motion as is done in complementary Molecular Dynamics simulations, the Monte Carlo method is based on stochastic “importance sampling” of the state space. This is realized through Markov chains which gives flexibility in the concrete realization of the sampling process and hence often allows for significant optimizations. The aim of this lab course was to provide the students with examples of Monte Carlo codes and give them hands-on experience in using them efficiently. In the lab course, the students first considered a simple toy model and wrote their own computer codes for its simulation and the data analyses. Then they generalized these tools step by step to more involved macromolecular systems.<\/p>\n<\/div>\n\n\n\n

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