SURFACE TENSION & WETTING
Dr. Günter K. Auernhammer
Group leader Surface Tension & Wetting
at the Leibniz-Institut für Polymerforschung Dresden e.V.
Hohe Strasse 6
Phone: +49 (0)351 4658-486
Fax: +49 (0)351 4658-474
- Kathrin Pöschel
- Stefan Michel
There is currently an increasing interest to control wetting and interfacial tension of polymeric materials for different applications and technologies such as coating, printing, joining, compatibility, self-cleaning, patterning and microfluidics. The desired surface properties range from complete release toward all contacting gaseous, liquid or solid substances to irreversible covalent bonding to other substrates of interest. Our preferred strategies to determine experimentally these parameters are contact angle measurements and the determination of the surface tension of polymer melts by drop shape analysis and modified Wilhelmy techniques.
For the determination of the surface tension of solid polymers, we use indirect methods based on wetting (contact angle) measurements in combination with specific approaches of interfacial energetics (e.g. equation of state approach for solid-liquid interfacial tensions). In the case of porous polymeric systems, such as powders, granules, fiber bundles or membranes, we developed a new strategy to characterize the surface-energetic properties of these materials by capillary penetration experiments with liquids of different surface tension and polarity.
In the focus of our work are interrelations between the surface tension and wettability of polymer surfaces and adhesion phenomena and the correlation of these macroscopic interfacial properties with the microscopic and molecular surface structure. Contact angle measurements carried out with different organic liquids can be also used to describe the reactivity of a substrate surface in the frame of the well-established electron pair acceptor and donator concepts.
Sessile, pendant drop and captive (adhering) bubble techniques
- DataPhysics OCA35L(DataPhysics, Germany)
- DataPhysics OCA40 micro(DataPhysics, Germany)
- FibroDat 1100(Fibro System AB, Sweden)
- FibroDat 1129 Automatic tilt table(Fibro System AB, Sweden)
- Different experimental set-up for Axisymmetric Drop Shape Analysis -Profile (ADSA-P)(in-house development)
Wilhelmy balance techniques
- Tensiometer K12(Kruess GmbH, Germany)
- Tensiometer DCAT21 (DataPhysics, Germany)
- Tensiometer DCAT21SF (single fiber (DataPhysics, Germany)
- OBS2 (in-house development tensiometer)
4 important publications
- Grundke, K.; Pöschel, K.; Synytska, A.; Frenzel, R.; Drechsler, A.; Nitschke, M.; Cordeiro, A.L.; Uhlmann, P.; Welzel, P.B., Advances in Colloid and Interfaces Science 2015, 222, 350-376.
- Grundke, K., Characterization of polymer surfaces by wetting and electrokinetic measurements- contact angle, interfacial tension, zeta potential, in Polymer Surfaces and Interfaces – Characterization, Modification and Applications (Chapter 6), ed. by Stamm, M., Springer-Verlag GmbH, Heidelberg, 2008, 103-138.
- Grundke, K., Surface-energetic properties of polymers in controlled architecture, in Molecular Interfacial Phenomena of Polymers and Biopolymers (Chapter 10), ed. by Chen, P., Woodhead Publishing Ltd., Sawston, UK, 2005, 323-374.
- Grundke, K., Wetting, Spreading and Penetration, in Handbook of Applied Surface and Colloid Chemistry (Chapter 7), ed. by Holmberg, K., John Wiley & Sons, Inc., New York, NY, USA, 2002, 119-140.