Stable emulsions formation by the drop microfluidics method

In the past two decades, new designs of microdevices have been searched, including for the production of microspheres with a diameter of 30 to 600 μm. The paper shows that the main material for designing chips of microfluidic devices is polydimethylsiloxane, this determines the choice of monomers, on the basis of which microspheres can be obtained, and also describes the main advantages and disadvantages of polydimethylsiloxane. The work demonstrated the possibility of creating a microfluidic device based on a brass chip with different channel geometry (180° and 120° angles). The regularities of its performance are examined and the conditions that make it possible to obtain stable spherical droplets of the emulsion: the flow rates of the internal phase (cyclohexane) and the dispersing phase (water), the concentration and nature of surface-active compounds (sodium dodecyl sulfate, polyethyleneglycol) are examined. It was shown that only with the use of a surfactant: SDS with a concentration of 50 CMC and polyethylenglycol (with a molecular weight of 40 000) with a concentration of 1 · 102 g / L, stable spherical droplets of a 250 μm cyclohexane / water emulsion are formed.