Polyelectrolytes: synthesis, characterization and complex formation


New, strictly alternating polyampholytes are synthesized by radical polymerization of N, N-diallyl-N, N-dimethylammonium chloride with N-substituted maleic acid amides. Alkyl or aryl chains of different hydrophilicity or hydrophobicity are inserted as side chains:

R = H [1],[3]
R = Butyl [1]
R = Octyl [2]
R = Phenyl [3],[4]
R = Biscarboxyphenyl [3],[4]

By varying the pH value, the conformation of the polyampholyte can be converted from a more elongated conformation (as a polycation or polyanion) into a more ball-like conformation (as a polyampholyte at the isoelectric point) [3].


  • Prof. A. Laschewsky (UP, IAP-FhG)
  • Prof. S. E. Kudaibergenov (Kazakh National Technical University, Almaty)

Selected Publications:

[1] C. Note, J. Ruffin, B. Tiersch, J. Koetz
The influence of polyampholytes on the phase behaviour of microemulsions used as template for the nanoparticle formation
J. Dispersion Sci. And Technology 28 (2007) 1, 155-164 | DOI: 10.1080/01932690600992217
[2] C. Note, J. Koetz, L. Wattebled, A. Laschewsky
Effect of a new hydrophobically modified polyampholyte on the formation of inverse microemulsions and the preparation of gold nanoparticles
J. Colloid and Interface Sci. 308 (2007) 162-169 | DOI: 10.1016/j.jcis.2006.12.047
[3] M. Fechner, J. Koetz
Polyampholyte-surfactant filmtuning in reverse microemulsions
Langmuir 27 (2011) 5316-5323 | DOI: 10.1021/la200791k
[4] M. Fechner, J. Koetz
Potentiometric Behavior of Polyampholytes Based on N,N’-diallyl-N,N’-dimethylammonium Chloride and Maleamic Acid Derivatives
Macromolecular Chemistry and Physics (2011) 212, 2691-2699 | DOI: 10.1002/macp.201100532

Polyplex formation

The complex formation between the polyanion DNA and the cationic polyelectrolyte is referred to as polyplex formation and is of particular interest for gene transfer. Polyethyleneimine (PEI) has proved to be a so-called "gold" standard with respect to the transfer properties. However, the disadvantage of the branched PEI is its cytotoxicity. Based on this knowledge, we investigated the complexing behavior of sugar-modified PEI samples and PEI-coated gold nanoparticles in cooperation with the Leibniz Institute (Dresden).


  • Dr. D. Appelhans (Leibniz-Institut, Dresden)

Selected Publications:

[5] J. Rumschöttel, S. Kosmella, C. Prietzel, D. Appelhans, J. Koetz:
Change in size, morphology and stability of DNA polyplexes with hyperbranched poly(ethyleneimines) containing bulky maltose units,
Colloids and Surfaces B 138 (2016) 78-85 | DOI: 10.1016/j.colsurfb.2015.11.061