Michael Kappl

Learn More
The hydrodynamic drainage force of aqueous medium between smooth hydrophilic surfaces was measured with the colloidal probe technique up to shear rates of typically 10(4) s(-1). Measured force curves were compared to simulations. To reach agreement between experimental and simulated force curves, the hydrodynamic force had to be fitted with a model allowing(More)
The kinetics of Na(+)-Ca2+ exchange current after a cytoplasmic Ca2+ concentration jump (achieved by photolysis of DM-nitrophen) was measured in excised giant membrane patches from guinea pig or rat heart. Increasing the cytoplasmic Ca2+ concentration from 0.5 microM in the presence of 100 mM extracellular Na+ elicits an inward current that rises with a(More)
A liquid meniscus between two lyophilic solid surfaces causes an attractive force, the capillary force. The meniscus can form by capillary condensation or by accumulation of adsorbed liquid. Under ambient conditions and between hydrophilic surfaces, capillary forces usually dominate over other surface forces. They are relevant in many processes occurring in(More)
In this study we measured the adhesion forces between atomic force microscope (AFM) tips or particles attached to AFM cantilevers and different solid samples. Smooth and homogeneous surfaces such as mica, silicon wafers, or highly oriented pyrolytic graphite, and more rough and heterogeneous surfaces such as iron particles or patterns of TiO2 nanoparticles(More)
To measure the interaction between two lipid bilayers with an atomic force microscope one solid supported bilayer was formed on a planar surface by spontaneous vesicle fusion. To spontaneously adsorb lipid bilayers also on the atomic force microscope tip, the tips were first coated with gold and a monolayer of mercapto undecanol. Calculations indicate that(More)
Silicatein-α is responsible for the biomineralization of silicates in sponges. We used silicatein-α to guide the self-assembly of calcite "spicules" similar to the spicules of the calcareous sponge Sycon sp. The self-assembled spicules, 10 to 300 micrometers (μm) in length and 5 to 10 μm in diameter, are composed of aligned calcite nanocrystals. The(More)
The interaction between particles with thin liquid films on solid surfaces was studied by sintering polystyrene microspheres of 4 to 5 microm diameter to the end of atomic force microscope cantilevers. Films of three silicone oils (viscosity 4.6, 9.2, and 9700 mPa s) and water of thickness 0.2-1.8 microm were formed on glass. The interaction between a(More)
The Ca(2+) concentration and voltage dependence of the relaxation kinetics of the Na-Ca exchanger after a Ca(2+) concentration jump was measured in excised giant membrane patches from guinea pig heart. Ca(2+) concentration jumps on the cytoplasmic side were achieved by laser flash-induced photolysis of DM-nitrophen. In the Ca-Ca exchange mode a transient(More)
Dry powder inhalers mostly contain carrier based formulations where micronized drug particles are adhered to coarse carrier particles. The performance of the dry powder inhaler depends on the inhaler device, the inhalation manoeuvre and the formulation. The most important factor influencing the behaviour of the formulation is the adhesion force acting(More)
An in situ study of the contact-free crystallization of calcium carbonate in acoustic levitated droplets is reported. The levitated droplet technique allows an in situ monitoring of the crystallization while avoiding any foreign phase boundaries that may influence the precipitation process by heterogeneous nucleation. The diffusion-controlled precipitation(More)