1 research outputs found
Surfactant-Free Polyurethane Nanocapsules via Inverse Pickering Miniemulsion
We
report on a surfactant-free synthesis of Pickering-stabilized
submicrometer-sized capsules in inverse miniemulsion. Functionalized
silica nanoparticles are able to stabilize water-in-cyclohexane miniemulsions
to form stable polyurethane shells via interfacial polyaddition. The
effect of the type of silica functionalization on the stabilizing
properties is demonstrated by varying the hydrophobicity and, therefore,
the contact angle between silica and the two liquid phases. Addition
of small amounts of salt leads to a reduction of the capsule size
and to a narrow size distribution. The impermeability of the formed
capsule shell is proven by encapsulation of an organic fluorescent
dye and release studies in aqueous environment. In addition, we show
the possibility to encapsulate large amounts of inorganic salts without
negative effects concerning the stability of the emulsion, which enables
the application for phase-change materials