Development of an innovative miniature emulsification device

Contant Persons: A. Chondrou [aggeliki1811@gmail.com]

This project aims to the design and construction of an innovative miniature emulsification device similar to FOAM – C cell, a device used for space experiments in the ISS. The schematic diagram of the emulsification device is presents in Fig. 1. The emulsification cell is rectangular with its main body made of aluminum whereas the cell walls are made of glass offering four ports, one at each side, for optical recordings and lighting. Almost the entire cross-section of the cell is scavenged by a thin aluminum plate fixed at the tip of a piston that moves up and down in the cell at controlled frequency and duration.

Figure 1: Schematic diagram of a) the emulsification device and b) the piston movement.

 

Figure 2: (a) Emulsification device and (b) step motor.

Millipore water and dodecane are mainly used to prepare emulsions in small volumes (3.4ml). The main surfactant which is used is Sodium Dodecyl Sulfate (SDS), the Critical Micellar Concentration of which is 2.5 g/L. Paraffin oil is also examined as oil phase for the preparation of emulsions with the surfactant Ethylan 1008 as emulsifier.

Two methods are used for the evaluation of emulsions’ stability: 1) phases’ separation (oil/water/emulsion) by computing the creaming index vs time from photographs taken with the Camera Canon EOS – 350D at different time intervals for several hours/days, and 2) droplet size distribution at the end of emulsification by analysis of microscopy images.

Essentially four parameters have been examined: 1) the oil : water ratio, 2) the concentration of the surfactant, 3) the stroke frequency and 4) the emulsification duration. The results have shown that the emulsification device (Fig.2) provides a satisfactory repeatability. The water phase separation and the droplet sizes are affected by all the different variables that have been examined (Fig. 3 and Fig. 4).

Figure 3: a) Phase separation of emulsions prepared with different concentration of the surfactant b) comparison of droplet size distributions

Figure 4: a) Phase separation of emulsions prepared with different duration of emulsification b) comparison of droplet size distributions

Video: Emulsification cell