title: In situ determination and imaging of physical properties of soft organic materials by analytical transmission electron microscopy.
abstract: Analytical transmission electron microscopy (ATEM) offers great flexibility in identification of the structural-chemical organization of soft materials at the level of individual macromolecules. However, the determination of mechanical characteristics such as hardness/elasticity of the amorphous and polycrystalline organic substances by ATEM has been problematic so far. Here, we show that energy filtered TEM (EFTEM) measurements enable direct identification and study of mechanical properties in complex (bio-)polymer systems of relevance for different industrial and (bio-)medical applications. We experimentally demonstrate strong correlations between hardness/elasticity of different polymers (polycaprolactone, polylactid, polyethelene, etc.) and their volume plasmon energy. Thickness and anisotropy effects, which substantially mask the material contrast in EFTEM bulk plasmon images, can be adequately removed by normalizing the latter by carbon elemental map. EFTEM data has been validated using atomic force microscopy phase images, where phase shift related to the hardness and elastic modulus of the materials.
authors.affiliation: 1Graz Centre for Electron Microscopy,Graz,Austria.
authors.forename: Nadejda B
authors.initials: NB
authors.lastname: Matsko
authors.affiliation: 2Institute for Electron Microscopy and Nanoanalysis,Graz University of Technology,Graz,Austria.
authors.forename: Franz P
authors.initials: FP
authors.lastname: Schmidt
authors.affiliation: 2Institute for Electron Microscopy and Nanoanalysis,Graz University of Technology,Graz,Austria.
authors.forename: Ilse
authors.initials: I
authors.lastname: Letofsky-Papst
authors.affiliation: 4J. R. Macdonald Laboratory,Department of Physics,Kansas State University,Kansas,USA.
authors.forename: Artem
authors.initials: A
authors.lastname: Rudenko
authors.affiliation: 5Department of Chemical Engineering,The Petroleum Institute,Abu Dhabi,UAE.
authors.forename: Vikas
authors.initials: V
authors.lastname: Mittal