(42e) Measuring Surface Forces between Micro-Drops in Microfluidic Devices and Using Direct Force Measurement

Attractive interactions between drops in which aggregation, rather than coalescence occur, control processes such as gel formation, fluid microstructure, the deposition of coatings and in formulated products (e.g., food, personal care products, pharmaceutical formulations). These forces are often very system specific and often a function of a number of additive components. This talk will focus on a new method using a microfluidic device to measure the attractive surface forces between drops that arise from multi-component complex fluids including polymers, polyelectrolytes or polymer-surfactant complexes. The outcomes of the interaction force behaviour measured in the the microfluidic device will be compared to detailed Atomic Force Microscopy (AFM) measurements between similar sized drops at the same solution conditions as those used in the microfluidic device. Aspects including the effect of drops size and and adsorption time scales in the two different measurement methods will also be discussed.