We demonstrate that sub-micron sized droplets (nano-droplets) of hydrocarbon solutions can be captured inside nanometer thick hydrated polymer shells by directly initiating polymerization in the aqueous phase from the surface of the nano-droplet. The pre-formulated nano-droplets are prepared into a mini-emulsion, which can be made sufficiently stable to withstand the growth and deposition of the polymer unto the surface of the emulsion droplet. We have successfully deposited few nanometer thick poly(N-isopropyl acrylamide) and poly(methacrylamide) layers onto oil droplets measuring 150 to 200 nm in diameters. The oil droplets can contain potentially fragile solute molecules (dyes) without interference in the polymer deposition. Our synthetic methods allow us to vary the thickness of the polymer layer, the size and composition of the oil droplet in a single step. We also demonstrate that the polymer capsules can subsequently be used as templates for further polymer deposition. This may allow us to build up layer-by-layer capsules with liquid hydrocarbon cores in the sub-micron range. We demonstrate the polymer capsule formation by NMR spectroscopy, dynamic light scattering and gel permeation chromatography as well as SEM microscopy. NMR spectroscopy is used to verify encapsulation of solute molecules as well as to investigate molecular mobility of the molecules.

Direct encapsulation of hydrocarbon solution nanodroplets via nucleation of polymer encapsulation from mini-emulsion templates

242nd National Meeting (2011)

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