Drop Shape Analyzer Analyses in interfacial rheology – time-saving and reproducible Emulsions and foams are constantly in motion during production or transport. The interfaces of droplets or bubbles are stretched during these processes. How such deformations impact on the stability of food and personal care products or influence the yield in tertiary crude oil production depends on how the surface tension or interfacial tension (SFT/IFT) responds to the stretching. Interfacial rheology measurements with the Drop Shape Analyzer – DSA30R provide the key to answering this question. Measuring methods and options ■ Emulsions and foams for food or personal care ■ Flooding mixtures and foam in enhanced oil recovery ■ Demulsifiers ■ Defoamers and antifoamers ■ Surfactant research ■ Measurement of interfacial rheological parameters such as the elastic modulus Eꞌ and viscous modulus Eꞌꞌ ■ Analysis of oscillating pendant or rising drops in a gaseous and liquid surrounding phase ■ Measurements on oscillating rising gas bubbles ■ Static surface and interfacial tension using pendant drop or constrained sessile drop

Elasticity and viscosity analysis in a wide dynamic range The measuring principle of the DSA30R involves evaluating video images of drops or gas bubbles at a dosing needle to measure the surface or interfacial tension (SFI/IFT). The interface size is sinusoidally changed during this process. The SFT/IFT is measured as a function of the surface change and is also sinusoidal in the case of samples containing surfactants. The dosing unit’s extremely precise piezo drive enables exact sine waves in a frequency spectrum of 0.001 to 20 Hz, so the measurements cover a very wide dynamic range. Oscillating...