Self-Disinfectant Surfaces - Correlation between Antimicrobial Activity and Zeta Potential

Zeta potential analysis enables the detection of functional groups introduced by additives in polymer compounds.

Microorganisms are ubiquitous in daily-life applications. They adhere to surfaces and multiply to form a colony of cells, which causes serious problems in particular in the food industry and in sanitary applications.

Maintenance-free sterile surfaces are a promising strategy to meet the requirement of long-term antimicrobial activity. The mechanism of the antimicrobial activity of polymers by mere contact has not yet been understood, though positive charges are known to play an important role.

Four blends of polypropylene and poly(2-oxazoline) derivatives were investigated for their antimicrobial activity and surface zeta potential analysis was performed.

The IEP (isoelectric point) of the compound plate containing pN100 was at pH 8.7, while those of the compound plates containing pN50A50 and pN25A75 were at pH 13.5. The IEPs thus revealed the surfi-cial presence of cationic functional groups.

Antimicrobial activity against different microorganisms was observed for compound plates containing small amounts of pN25A75 and pN50A50 and correlates with the IEPs obtained by zeta potential measurements.


  • Kelly A. M., Kaltenhauser V., Mühlbacher I., Rametsteiner K., Kren H., Slugovc C., Stelzer F., Wiesbrock F., Macromol. Biosci.13 (2013) 116-125
  • Data provided by Dr. Inge Mühlbacher, Univ.-Doz. Dr. Frank Wiesbrock, Polymer Competence Center Leoben GmbH

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