Affiliation:
1. Microscopy of Nanoscale Structures & Mechanisms (MNM) Laboratory for Electron Microscopy (LEM) Karlsruhe Institute of Technology (KIT) 76131 Karlsruhe Germany
2. Institute for Applied Materials (IAM) Karlsruhe Institute of Technology (KIT) 76131 Karlsruhe Germany
3. Institute of Microstructure Technology (IMT) Karlsruhe Institute of Technology (KIT) 76344 Eggenstein‐Leopoldshafen Germany
4. Institute of Energy and Climate Research (IEK) Forschungszentrum Jülich GmbH 52428 Jülich Germany
5. Fraunhofer Institute for Mechanics of Materials (IWM) 79108 Freiburg Germany
Abstract
AbstractThis study presents a novel approach for investigating the shrinkage dynamics of 3D‐printed nanoarchitectures during isothermal pyrolysis, utilizing in situ electron microscopy. For the first time, the temporal evolution of 3D structures is tracked continuously until a quasi‐stationary state is reached. By subjecting the 3D objects to different temperatures and atmospheric conditions, significant changes in the resulting kinetic parameters and morphological textures of the 3D objects are observed, particularly those possessing varying surface‐to‐volume ratios. Its results reveal that the effective activation energy required for pyrolysis‐induced morphological shrinkage is approximately four times larger under vacuum conditions than in a nitrogen atmosphere (2.6 eV vs. 0.5–0.9 eV, respectively). Additionally, a subtle enrichment of oxygen on the surfaces of the structures for pyrolysis in nitrogen is found through a postmortem electron energy loss spectroscopy study, differentiating the vacuum pyrolysis. These findings are examined in the context of the underlying process parameters, and a mechanistic model is proposed. As a result, understanding and controlling pyrolysis in 3D structures of different geometrical dimensions not only enables precise modification of shrinkage and the creation of tensegrity structures, but also promotes pyrolytic carbon development with custom architectures and properties, especially in the field of carbon micro‐ and nano‐electromechanical systems.
Subject
Electrochemistry,Condensed Matter Physics,Biomaterials,Electronic, Optical and Magnetic Materials