Transmissionselektronenmikroskop

• Subject Area: Process Engineering, Technical Chemistry
• Term: Funded in 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 163605501

• Final Report Year: 2016

Final Report Abstract

1.) DNA-Polykation Komplexe (Polyplexe): Polyplexes between salmon DNA and hyperbranched poly(ethyleneimines) modified with maltose units were characterized by means of scanning transmission electron microscopy (STEM) recorded at 200 kV using a high-angle annular dark-field detector. 2.) Biomineralisation in Templatphasen: Supramolecular calcium phosphate card house structures are formed by dropping a natrium hydrogen phosphate precursor solution into a calcium chloride solution at 90°C in presence of two biopolymers, i.e., gelatin and chitosan. HRTEM microgaphs show that the resulting nano-porous calcium phosphate balls consists of individual dicalcium phosphate crystal platelets. 3.) Nanopartikel definierter Form und Größe: Ultrasmall spherical gold nanoparticles and fluorescent gold clusters were synthesized in a poly(ethyleneimine)- modified reverse microemulsion template phase. After a complete solvent evaporation gold nanoclusters with diameter < 2nm were characterized by means of HRTEM. Asymmetric goldnanoparticles, i.e., flat gold nanotriangles, were synthesized in a vesicular template phase and separated from spherical gold nanoparticles by a combined micelle/polyelectrolyte depletion flocculation. The isolated purified gold nanotriangles were characterized by HRTEM. The fast Fourier transform of the single flat crystals show a six-fold symmetry of the fcc lattice.

Publications

• Fluorescent gold clusters synthesized in a poly(ethyleneimine) modified microemulsion. J Colloid Interface Sci 394 (2013) 141-146
  K. Lemke, C. Prietzel, J. Koetz
  
• Nano-porous calcium phosphate balls. Colloids Surfaces B 132 (2015) 246-252
  I. Kovach, S. Kosmella, C. Prietzel, C. Bagdahn, J. Koetz
  
• "Green" gold nanotriangles: synthesis, purification by PEL/micelle depletion flocculation and performance in surface-enhanced Raman scattering. RSC Advances 6 (2016) 33561-3356
  F. Liebig, R.M Sarhan, C. Prietzel, A. Reinicke, J. Koetz
  
• Change in size and, morphology and stability of DNA polyplexes with hyperbranched poly(ethyleneimines) containing bulky maltose units. Colloids Surfaces B 138 (2016) 78-8
  J. Rumschöttel, S. Kosmella, C. Prietzel, D. Appelhans, J. Koetz
  
• Polyampholyte mediated synthesis of anisotropic gold nanoplatelets. Colloid Polym. Sci. (2016)
  N. Schulze, C. Prietzel, J. Koetz