We will discuss strategies for making novel responsive classes of soft matter and nanomaterials by using multiphasic fluids and particle-controlled interfacial effects. One such class of materials can be formed when light or field-responsive particles are embedded into foams, emulsions and colloidal gels. In the first part of the talk we will present the design and characterization of a few types of very stable, yet stimuli-responsive, Pickering foams. These foams are stabilized by rod-like polymer particles or ones made from hydrophobically modified cellulose. By addition of carbonyl iron particles into the matrix, these Pickering systems can be made photo- as well as thermally sensitive, resulting in novel photo-thermo-magneto responsive foams. In the second part of the talk, we will describe a new smart multiphasic gel system containing ultraflexible chains assembled from magnetically responsive nanoparticles bound by liquid lipid bridges. The initial application of an external magnetic field aligns the superparamagnetic nanoparticles into chains, where they become bound by the soft attractive potential induced by the surface-condensed lipid. The liquid bridges allow for particle rolling and sliding, and the resulting chain flexibility was measured to be orders of magnitude higher than any other linear structures reported to date. The nanoparticles binding through soft, "snappable" liquid bridging provides a facile means of creating self-repairing gel networks. Such flexible responsive multiphasic structures can be used in applications such as switchable assemblies of patchy particles, and novel colloidal inks for 3D printing. Finally, we will discuss the development of scalable, rapid and efficient processes for synthesis of functional nanomaterials by precipitation under shear in biphasic systems. The ultralow interfacial tension between oil droplets and shear medium enables the formation of high surface area liquid structures, which can serve as templates for the formation of diverse classes of polymer and biopolymer materials, at least one characteristic dimension of which may be on the nanoscale. Our “shear nanospinning” technique opens the way to scalable manufacture of nanofibers and a broad range of polymer nanomaterials.

Strategies for making smart foams, emulsions and multiphasic gels stabilized by functional particles

253rd National Meeting (2017)

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