Complex multi-phase droplets have opened new frontiers of “designer” emulsions where chemistries and processes can be compartmentalized to control encapsulation and chemical reactions within droplets, providing utility in nanobiotechnology, foods, and particulate materials design. However, most processes to produce complex emulsions are limited to large droplets at low throughput (e.g. microfluidics) or droplets with significant size and morphology dispersity (e.g. high-energy emulsification). A significant technology gap therefore exists in scalable methods to produce complex emulsions with nanoscopic dimensions, i.e., nanodroplets within nanodroplets. Here, I summarize our recent strategies toward the development of scalable processes to produce complex nanoemulsions, and the important applications they give rise to [1]. First, we discuss the physical challenges in creating complex emulsions at the nanoscale, and how they can be overcome by careful engineering of interfacial properties (through surfactant design) and the fluid mechanics of emulsification (using high-energy processing). Second, we show how compartmentalization of material chemistry in multi-phase nanodroplets can be used to template nanoparticles and nanocapsules with a range of morphologies and structures for nanoparticle and encapsulation design. In particular, we have demonstrated the controlled synthesis of novel nanogel particles with independent control over particle size, internal composition, and mechanical properties that provide unique opportunities for nanoencapsulation and controlled release [2]. Finally, we show how nanoemulsion-templated complex nanogels can be used for a number of fundamental studies and functions for applications in foods, neutraceuticals and drug delivery.

Prof. Matthew Helgeson

UC Santa Barbara

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