Electron Microscopy

Transmission Electron Microscopy

Electron microscopy is a high-resolution method that can provide important contributions to structure elucidation for many applications and questions. In addition to optical and scanning probe-assisted microscopy methods, transmission electron microscopy in particular provides the highest structural resolution and has therefore established itself as a central method in the area of 'soft matter'. Central applications in this area include e.g. the investigation of:

  • Thin, phase-separated polymer films
  • Supramolecular aggregates in solutions
  • Nanoparticles
  • Biological sample systems

Central areas of application at the Jena Center for Soft Matter are the study of tailor-made block copolymers, e.g. to be used as drug containers. With the aid of transmission electron microscopy, both its structure and its loading behavior can be studied here. In addition, polymer morphologies of phase-separated polymers can also be investigated.

Particularly in the field of biological applications and in the investigation of the aggregation behavior of block copolymer systems in solution special requirements are placed on the sample preparation. Here, the cryo-transmission electron microscopy has proved successful, in which the sample systems are embedded in a very fast freezing process in a thin amorphous ice film, in which the transmission electron microscopy studies at a temperature of -180 ° C are performed. This allows the examination of the samples in a solvent-like state.

1344/5000With the existing infrastructure, sample systems can also be analyzed with regard to their three-dimensional structure. This method measures selected objects under different illumination angles. The totality of the different cutting planes allows a back projection and the final development of a three-dimensional model of the individual objects.

The existing options will soon be greatly expanded by the installation of a modern transmission electron microscope within the Jena Center for Soft Matter. This will also provide a chemical analysis of sample systems with nanometer resolution resolution through the use of Scanning Transmission Electron Microscopy (STEM) in combination with EDX analysis.

In addition to the application of standardized preparation processes, the development of novel methods is also the focus of research. Here, in addition to the development of the freeze-fracture sample preparation, which is operated in the electron microscope center, worked in particular on an approach that allows self-assembled supramolecular block copolymers and nanoscale objects in a suitable liquid image. This approach then allows temporal analysis of the diffusion and motion of individual supramolecular objects with the highest resolution.

Recent publications on the subject

U. Mansfeld, A. Winter, M. D. Hager, G. Festag, S. Hoeppener, U. S. Schubert, "Amphiphilic supramolecular A(B)(2)A quasi-triblock copolymers", Polym. Chem. 2013, 4, 3177-3181.

U. Mansfeld, S. Hoeppener, U. S. Schubert, "Investigating the Motion of Diblock Copolymer Assemblies in Ionic Liquids by In Situ Electron Microscopy", Adv. Mater. 2013, 25, 761-765.

U. Mansfeld, S. Hoeppener, K. Kempe, J. M. Schumers, J. F. Gohy, U. S. Schubert, "Tuning the morphology of triblock terpoly(2-oxazoline)s containing a 2-phenyl-2-oxazoline block with varying fluorine content", Soft Matter 2013, 9, 5966-5974.

M. M. Bloksma, S. Hoeppener, C. D'Haese, K. Kempe, U. Mansfeld, R. M. Paulus, J.-F. Gohy, U. S. Schubert, R. Hoogenboom, "Self-assembly of chiral block and gradient copolymers", Soft Matter 2012, 8, 165-172.

A. Can, S. Hoeppener, P. Guillet, J.-F. Gohy, R. Hoogenboom, U. S. Schubert, "UCST Switchable Micelles Based on PS-b-PMA Block Copolymers", J. Polym. Sci. Part A 2011, 49, 3681-3687.

J. F. Gohy, N. Lefevre, C. D'Haese, S. Hoeppener, U. S. Schubert, G. Kostov, B. Ameduri, "Multicompartment Micelles from Blends of Terpolymers", Polymer Chemistry 2011, 2, 328-332.

T. S. Druzhinina, N. Herzer, S. Hoeppener*, U. S. Schubert, "Formation of Iron Oxide Particles by Reduction with Hydrazine", ChemPhysChem 2011, 12, 781-784. 

K. Kempe, R. Hoogenboom, S. Hoeppener, J. F. Gohy, U. S. Schubert, "Discovering New Block-terpolymer Micellar Morphologies", Chem. Commun. 2010, 46, 6455-6457. 

C.-A. Fustin, H. M. L. Thijs-Lambermont, S. Hoeppener, R. Hoogenboom, U. S. Schubert, J. F. Gohy, "Multiple Micellar Morphologies from Tri- and Tetrablock Copoly(2-oxazoline)s in Binary Water-Ethanol Mixtures", J. Polym. Sci. Part A 2010, 48, 3095-3102.