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Interfacial Structure of Pickering Emulsions Kjersta Larson-Smith and Prof. Danilo Pozzo University of Washington Chemical Engineering, Seattle WA • Particle stabilized emulsions (Pickering) form during the processing of organic fluids in the presence of water and solid micro and/or nanoparticles. • Particles are enriched at the oil-water interface due to a favorable energy of adsorption. • Stabilization may be electrostatic or can occur through the creation of an elastic shell that prevent drop coalescence. • Emulsion stability is controlled primarily by the organization of solid particles at the interface. • Project goals: – Develop an experimental toolbox to probe the interfacial organization of the particles in the emulsion. – Probe interfacial transitions that occur in Pickering emulsions that are subjected to destabilizing freeze-thaw cycles. Oil Model Emulsions: Hexadecane stabilized by functionalized gold and silica nanoparticles (4-100 nm) Small Angle Neutron and X-ray Scattering Electrostatic Stabilization + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Electrostatic Stabilization + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Electrostatic Stabilization + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Steric Stabilization Steric Stabilization 10 -2 10 -1 10 0 10 1 10 2 10 3 10 4 10 5 10 6 I(q)(cm -1 ) 10 -5 10 -4 10 -3 10 -2 10 -1 10 0 q (Å -1 ) SANS/USANS 16nm SiO 2 P ickering E m ulsion M odel Fit Water 50 m Electrostatics dominate nanoparticle stabilized emulsions

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Interfacial Structure of Pickering Emulsions Kjersta Larson-Smith and Prof. Danilo Pozzo University of Washington Chemical Engineering, Seattle WA. Oil. - PowerPoint PPT Presentation

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Interfacial Structure of Pickering EmulsionsKjersta Larson-Smith and Prof. Danilo Pozzo

University of Washington Chemical Engineering, Seattle WA

• Particle stabilized emulsions (Pickering) form during the processing of organic fluids in the presence of water and solid micro and/or nanoparticles.

• Particles are enriched at the oil-water interface due to a favorable energy of adsorption.

• Stabilization may be electrostatic or can occur through the creation of an elastic shell that prevent drop coalescence.

• Emulsion stability is controlled primarily by the organization of solid particles at the interface.

• Project goals: – Develop an experimental toolbox to probe the interfacial organization of the particles in the emulsion. – Probe interfacial transitions that occur in Pickering emulsions that are subjected to destabilizing freeze-thaw cycles.

Oil

Model Emulsions: Hexadecane stabilized by functionalized gold and silica nanoparticles (4-100 nm)

Small Angle Neutron and X-ray Scattering Electrostatic Stabilization

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Electrostatic Stabilization

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