![]() ![]() Thermally responsive emulsions were created with the SiO 2−PDMAEMA particles such that stable emulsions prepared at low temperature were rapidly broken by increasing the temperature above the CFT. Emulsions have been stable for over 13 months, and some have dispersed as much as 83 vol % oil in the emulsion phase. Both good (xylene) and poor (cyclohexane) solvents could be emulsified, but the poor solvent could be emulsified over a broader range of conditions than the good solvent. The lowest grafting density particles (0.077 chains/nm 2) proved to be the most efficient and robust emulsifiers, producing stable emulsions using as little as 0.05 wt % particles in the aqueous phase and successfully emulsifying over a broader range of solution conditions than for the higher grafting density particles (0.36 and 1.27 chain/nm 2). The preferred emulsion type was oil in water in all cases. The stability of Pickering emulsions investigated so far depends largely on the inherent properties of the stabilising material. ![]() The effects of the solvent quality of the “oil” for the PDMAEMA brush were studied in addition to the effects of aqueous pH, ionic strength, and temperature relative to the CFT. Pickering emulsions stabilised by various biodegradable solid particles and macromolecules have proven to be an excellent alternative to synthetic surfactant-based emulsions. ATRP provides a high degree of control over the brush grafting density and degree of polymerization, two of the principal variables examined in this study. Accordingly, SiO 2−PDMAEMA nanoparticles were thermally responsive, as shown by the fact that they displayed a critical flocculation temperature (CFT) when heated. Pickering, who described the phenomenon in 1907, although the effect was first recognized by Walter Ramsden in 1903. This type of emulsion was named after S.U. PDMAEMA is a water-soluble weak polyelectrolyte with a pH-dependent lower critical solution temperature (LCST). A Pickering emulsion is an emulsion (either water-in-oil or oil-in-water) that is stabilized by solid particles (for example colloidal silica) which adsorb onto the interface between the two phases. The grafted nanoparticles were used to stabilize xylene-in-water and cyclohexane-in-water Pickering emulsions. Rheology of particle laden interfaces and Pickering emulsionsĥ.A study is presented of emulsification by silica nanoparticles with poly(2-(dimethylamino)ethyl methacrylate) brushes grafted from their surfaces (SiO 2−PDMAEMA) by atom-transfer radical polymerization (ATRP). Pickering emulsion, which is an emulsion stabilized by solid particles, offers a wide range of potential applications because it generally provides a more stable system than surfactant- stabilized emulsion. Interfacial assembly and emulsion stabilizationĤ. Pickering emulsion-based polymerizationģ. Interactions of colloidal particles confined at fluid interfacesĢ. The themes include, but are not limited to:ġ. The present "Pickering Emulsion and Derived Materials" Special Issue aims to bring together research and review papers pertaining to the recent developments in the design, fabrication, and application of Pickering emulsions. While much progress has been made over the past decade, Pickering emulsion still remains a rich topic since many aspects of their behavior have yet to be investigated. ![]() The exploitation of these Pickering emulsions for the manufacture of new functional materials has also recently become the subject of intense investigation. Particle-stabilized emulsions, today often referred to as Pickering/Ramsden emulsions, are vital in many fields, including personal care products, foods, pharmaceuticals, and oil recovery. ![]()
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