A new method for preparation of poly-lauryl acrylate nanoparticles from nanoemulsions obtained by the phase inversion temperature process

We describe a new method for the preparation of organic nanoparticles from nanoemulsions which were prepared by the phase inversion temperature (PIT) method. This is a low-energy technique which does not require any special equipment such as high pressure homogenizers. In this work, the method is demonstrated for preparation of nanoparticles of poly-lauryl acrylate containing, in some cases, a crosslinker (trimethylolpropane triacrylate-TMPTA) and pyrene as microviscosity and micropolarity probes, respectively. The nanoemulsions were prepared by using a poly(oxyethylene) nonionic surfactant, Brij 96V (POE (10) oleyl alcohol), and combinations of Brij 96V and Brij 92V (POE (2) oleyl alcohol), with acrylate monomers which form the oil phase in the oil-in-water (O/W) emulsions. The nanodroplets were polymerized, yielding nanoparticles having an average diameter between 50 and 120 run with a narrow size distribution, using a water-soluble thermal initiator (ammonium persulfate) and activated by ferrous ions, Fe+2. The emission colors of the pyrene-embedded nanoemulsions changed from blue to violet after polymerization, due to the absence of excimers. This method may be applied for the preparation of a variety of polymeric nanoparticles, in which functional molecules are embedded within the particles. Copyright (c) 2007 John Wiley & Sons, Ltd.