Controlling the formation of particle-stabilized water-in-oil emulsions

Complex ceramic architectures by directed assembly of ‘responsive’ particles

“…In addition, the repulsion forces between the BCS functionalized particles in the "skin" of a droplet with the particles in the "skin" of an adjacent one will contribute to avoid droplet coalescence and maintain a stable emulsion. We have also found that BCS increases the contact angle of water on alumina surfaces (Figure 3e, f), which may increase the energy required to remove the functionalized particle from the oil/water interface [22,33]. It is highly likely that a combination of particle and surfactant (BCSr) stabilization is taking place at the oil/water interface [12].…”

“…A lower amount of particles in the suspensions strongly affects the emulsification, due to a lower viscosity of the continuous phase, and the decrease on the probability to hit the interface and surface coverage. This shifts the mixing conditions from the rupture controlled to the coalescence-controlled domain [22]. Emulsions prepared with low viscosity suspensions (7-25 vol%, Figure 3a) are less stable, leading to creaming and phase separation within an hour when prepared at emulsification speeds below 10,000 rpm.…”

“…Under these conditions the crowd of BCS functionalised particles facilitate droplet breakup, creating a shell on the surface and avoiding coalescence; the emulsification takes place in the rupture controlled domain [22,34]. The parameters affecting the emulsification in this region are particle concentration and shear rate.…”

“…Emulsion templating is another path used to fabricate cellular ceramics, metals and polymers [12][13][14][15][16][17][18][19][20]. Although particle stabilized emulsions are known for more than a century [21], many authors have delved into their understanding and application to build cellular materials in recent studies [13,15,22,23]. The oil droplets act as a temporary template and determine the morphological features in the final porous structures.…”

New composite separator pellet to increase power density and reduce size of thermal batteries

“…Pickering emulsion properties such as drop size and porosity are adaptable by varying processing conditions. For example, mixing speed (Gurevitch and Silverstein, 2010;Sturzenegger et al, 2012), particle concentration (Arditty et al, 2003;Binks and Whitby, 2004;Sturzenegger et al, 2012), particle wettability (Akartuna et al, 2008b;Bachinger and Kickelbick, 2010;Chuanuwatanakul et al, 2011;Haase et al, 2011), particle aspect ratio (Vandebril et al, 2010), particle roughness (San-Miguel and Behrens, 2012), and particle size (Binks and Lumsdon, 2001) have all been studied. Such wet emulsions can be shaped, extruded into forms or coated into sheets because of their measurable yield stress Chen et al, 2012).…”