Rotating membrane emulsification

Rotating membrane emulsification is another type of batch emulsification. In this case a tubular membrane immersed in a continuous phase vessel is rotating itself and its angular velocity creates the shear stress at the membrane surface (Figure 21.14). 

DEs (e.g. W/OAV or OAV/0) were prepared by a two-step method applying an additional rotational membrane process (ROME, ETH Ziiiich/Kinematica AG Luzem, CH) and using the same emulsifiers and stabilizers applied for SE (Table 23.1). At first, the SE was prepared by the rotor-stator device at high rotational speed (up to 10,000 rpm) for tK, 15-20 min at constant temperature (22-23 °C) as described before. The primary droplet size was adjusted between 1 and 2 pm, by the rpm of the rotor-stator device and treatment duration. This SE was then used as the disperse phase in the rotary membrane emulsification (ROME) device. The gentle rotational membrane emulsification/foaming process had been developed at the Laboratory of Food Process Engineering (ETH Zurich) within the past decade and reported elsewhere [29,52,39]. The membrane emulsification has... 

Figure 6.3 Examples of rotating membranes used for emulsification (a) Rotating membrane fabricated by deposition of pure carbon layer on the microporous nickel substrate (Schadler and Windhab, 2004, 2005) (b) rotating stainless steel membrane with laser drilled pores (Vladisavljevic and Williams, 2006) (c) a rotating membrane emulsification system in operation (Vladisavljevic and Williams, 2006).

Vladisavljevic GT, Williams RA. 2006. Manufacture of large uniform droplets using rotating membrane emulsification. / Colloid Interface Sci 299 396-402. 

The membrane emulsification can be considered as a case of microdevice emulsification process [17, 18] in which the porous membrane is used as microdevices. Membrane emulsification carried out in quiescent conditions is also referred to as static membrane emulsification, while membrane emulsification carried our in moving conditions (either the membrane, i.e., rotating module, or the phase, i.e., crossflow) is also referred to as dynamic membrane emulsification (Figure 21.2(b)). 

Figure20.9 Processing applications ofmembrane emulsification rotating membranes [53, 54, 56] and premix membrane emulsification [49, 51, 57],...

Fig. 23.10 Setup for spraying of DEs (W1/0/W2) including rotating membrane double emulsification (step 2) for iron tracer encapsulation in innermost watery phase (Wl) using air-assist nozzles...

---