title: Self-assembly of nanoparticles employing polymerization-induced phase separation.
abstract: Nanoparticles (NPs) may be homogeneously dispersed in the precursors of a polymer (reactive solvent) by an adequate selection of their stabilizing ligands. However, the dispersion can become metastable or unstable in the course of polymerization. If this happens, NP-rich domains can be segregated by a process called polymerization-induced phase separation (PIPS). This occurs mainly due to the decrease in the entropic contribution of the reactive solvent to the free energy of mixing (increase in its average size) and, for a reactive solvent generating a cross-linked polymer, the additional contribution of the elastic energy in the post-gel stage. The extent of PIPS will depend on the competition between phase separation and polymerization rates. It can be completely avoided, limited to a local scale or conveyed to generate different types of NPs' aggregates such as crystalline platelets, self-assembled structures with a hierarchical order and partitioning at the interface, and bidimensional patterns of NPs at the film surface. The use of a third component in the initial formulation such as a linear polymer or a block copolymer, provides the possibility of generating an internal template for the preferential location and self-assembly of phase-separated NPs. Some illustrative examples of morphologies generated by PIPS in solutions of NPs in reactive solvents, are analyzed in this feature article.
authors.affiliation: Institute of Materials Science and Technology (INTEMA), University of Mar del Plata and National Research Council (CONICET), Av. J. B. Justo 4302, 7600 Mar del Plata, Argentina. Electronic address: williams@fi.mdp.edu.ar.
authors.forename: Roberto J J
authors.initials: RJ
authors.lastname: Williams
authors.affiliation: Institute of Materials Science and Technology (INTEMA), University of Mar del Plata and National Research Council (CONICET), Av. J. B. Justo 4302, 7600 Mar del Plata, Argentina.
authors.forename: Cristina E
authors.initials: CE
authors.lastname: Hoppe
authors.affiliation: Institute of Materials Science and Technology (INTEMA), University of Mar del Plata and National Research Council (CONICET), Av. J. B. Justo 4302, 7600 Mar del Plata, Argentina.
authors.forename: Ileana A
authors.initials: IA
authors.lastname: Zucchi
authors.affiliation: Institute of Materials Science and Technology (INTEMA), University of Mar del Plata and National Research Council (CONICET), Av. J. B. Justo 4302, 7600 Mar del Plata, Argentina.
authors.forename: Hernán E
authors.initials: HE
authors.lastname: Romeo
authors.affiliation: Institute of Materials Science and Technology (INTEMA), University of Mar del Plata and National Research Council (CONICET), Av. J. B. Justo 4302, 7600 Mar del Plata, Argentina.
authors.forename: Ignacio E
authors.initials: IE
authors.lastname: dell'Erba
authors.affiliation: Institute of Materials Science and Technology (INTEMA), University of Mar del Plata and National Research Council (CONICET), Av. J. B. Justo 4302, 7600 Mar del Plata, Argentina.
authors.forename: María L
authors.initials: ML
authors.lastname: Gómez
authors.affiliation: Institute of Materials Science and Technology (INTEMA), University of Mar del Plata and National Research Council (CONICET), Av. J. B. Justo 4302, 7600 Mar del Plata, Argentina.
authors.forename: Julieta
authors.initials: J
authors.lastname: Puig
authors.affiliation: Institute of Materials Science and Technology (INTEMA), University of Mar del Plata and National Research Council (CONICET), Av. J. B. Justo 4302, 7600 Mar del Plata, Argentina.
authors.forename: Agustina B
authors.initials: AB
authors.lastname: Leonardi
keywords: Block copolymers; Nanoparticles; Nanoparticle–polymer blends; Phase separation; Polymerization-induced phase separation; Self-assembly