Reprint of: Self-assembly of nanoparticles employing polymerization-induced phase separation

R. J. J. WILLIAMS; C. E. HOPPE; I. A. ZUCCHI; H. E. ROMEO; I. E. DELL?ERBA; M. L. GÓMEZ; J. PUIG; A.B. LEONARDI

JOURNAL OF COLLOID AND INTERFACE SCIENCE

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2014 vol. 447 p. 129 - 138

0021-9797

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 orunstable in the course of polymerization. If this happens, NP-rich domains can be segregated by a processcalled polymerization-induced phase separation (PIPS). This occurs mainly due to the decrease in theentropic 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 elasticenergy in the post-gel stage. The extent of PIPS will depend on the competition between phase separationand polymerization rates. It can be completely avoided, limited to a local scale or conveyed to generatedifferent types of NPs? aggregates such as crystalline platelets, self-assembled structures with a hierarchicalorder and partitioning at the interface, and bidimensional patterns of NPs at the film surface. The useof a third component in the initial formulation such as a linear polymer or a block copolymer, providesthe possibility of generating an internal template for the preferential location and self-assembly of phaseseparatedNPs. Some illustrative examples of morphologies generated by PIPS in solutions of NPs in reactivesolvents, are analyzed in this feature article.