The quantitative impact of fluid vs. solid interfaces on the catalytic performance of pickering emulsions

Abstract

The activity of the catalyst is the same at the particles and at the void surface between the particles.

Organic Solvent Nanofiltration of Water-in-Oil Pickering Emulsions—What Influences Permeability?

“…For all emulsions, deionized water was used as the aqueous phase. Based on our previous work [13][14][15]17,18], 1-dodecene was used as the "standard" organic solvent (VWR International GmbH, Dresden, Germany), as it constitutes a representative long-chain olefin suited for, e.g., hydroformylation reactions (e.g., [18]). Additionally, dodecane (Fisher Scientific GmbH, Schwerte, Germany), decene (Sigma-Aldrich Chemie GmbH, Taufkirchen, Germany), octene (Fisher Scientific GmbH, Schwerte, Germany) and heptane (Th.…”

“…[g mol −1 ] [kg m −3 Different types of silica nanoparticles were used (Table 2). Commercially available fumed fractal-like particles of varying hydrophobicity and specific particle surface area by Wacker Chemie AG (as published in our previous works [14,15]) and spherical inhouse particles differing in charge or size (as published in our previous work [18]) were investigated. The particles will be referred to by the short names given in Table 2 in the following.…”

“…All emulsions were prepared using a batch rotor-stator homogenizer (IKA ® -Werke GmbH & Co. KG, Staufen, Germany; IKA T 25 digital ULTRA-TURRAX ® , P max = 500 W). While PEs stabilized by particle types H15, H20, H30 and H2000 were prepared using the S25N-18G dispersing head at constant homogenization conditions of 17,500 min −1 /2 min [13], PEs stabilized by particle types 50−, 50+ and 100+ were prepared using the S25N-10G dispersing head at 20,000 min −1 /5 min [18]. All experiments were conducted with individually prepared emulsions at room temperature (T = 22.2 ± 1.3 • C).…”

“…Consequently, all PEs reduced this permeability by only approximately 40%. Using the oNF-3 membrane, the particle type used for PE stabilization can be adjusted to optimize the actual reaction without any significant loss in filtration performance (e.g., small drop sizes for large interfacial area or specific particle charge to optimize particle-catalyst interactions [18]).…”

“…Mean values are shown and error bars represent the standard deviation. Drop size distributions for particle types H15, H20, H30 and H2000 were already published in [14] and Sauter mean diameters for particle types 50− and 50+ were published in [18].…”