INIFTA   05425
INSTITUTO DE INVESTIGACIONES FISICO-QUIMICAS TEORICAS Y APLICADAS
Unidad Ejecutora - UE
capítulos de libros
Título:
Morphological properties of some inorganic polymers
Autor/es:
EZEQUIEL WOLCAN; GUSTAVO T. RUIZ; GUILLERMO J. FERRAUDI
Libro:
Polymer Morphology. Series: Chemistry Research and Applications.
Editorial:
Hongshun Yang. Hauppauge: Nova Science Publishers
Referencias:
Año: 2012; p. 183 - 225
Resumen:
The morphologies of several inorganic polymers containing different metal ions (AlIII, CoII, CuII RhIII and ReI) metalating various organic backbones (poly-acrylate, poly-ethyleneimine and poly-4-vinylpyridine) were studied by Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), Static Light Scattering (SLS) and Dynamic Light Scattering (DLS). SLS and DLS studies on acetonitrile (ACN) solutions of the polymer {[(vpy)2-vpyRe(CO)3bpy] CF3SO3}200 (vpy = 4-vinylpyridine, bpy = 2,2´bipyridine) demonstrated that the ReI polymer molecules aggregate to form spherical nanodomains of radius R ~ 156 nm. Coordination of CuX2 (X=Cl or CF3SO3) species to the ReI-polymer causes a decrease in the nanodomain radius and a distortion from the spherical shape. The morphologies of ReI-polymer and ReI-polymer-CuCl2 were also studied by TEM. In the solid phase of the ReI-polymer, the ReI complexes aggregate and form isolated nanodomains that are dispersed in the poly-4-vinylpyridine backbone. The dimensions of the nanodomains are between 90 and 430 nm and are mainly spherical in shape. However, the ReI-polymer-CuCl2 aggregate to form nanodomains that are distorted from the spherical shape and whose dimensions are smaller than those nanoaggregates formed by the ReI-polymer. It should be noted that the dimensions of the two kind of nanodomains are considerably larger than the full stretch length of the polymers. As a result, it is likely that the nanodomains contain more than one layer of polymers. New RhIII polymers were obtained when poly-acrylate was derivatized with RhIII(pc) (pc = phthalocyanine). The morphology of the strands of poly(acrylate) polymers containing various loads of    RhIII(pc) coordinated to pendent    CO2- groups was established by AFM microscopy. The strands of the polymer, poly-RhIII(pc), were seen as the strings of spherules expected for an hypercoiled poly(acrylate) backbone. These strings of spherules indicated the hypercoiling of the poly(acrylate) backbone in a manner resembling the hypercoiled poly(metaacrylate). The UV-vis spectroscopy of poly-RhIII(pc) shows a large fraction of    CO2RhIII(pc) pendants forming stacks in the strand of poly(acrylate) polymer. A similar stacking has not been observed in homogeneous solutions of XRhIII(pc) (X = Cl, Br, I), and it must be regarded as an intrinsic phenomenon of the poly-RhIII(pc). The stacks of    CO2RhIII(pc) pendants are likely to be located inside the spherules observed in the AFM microscope. A new polyimide containing pendant AlIIIphthalocyanine-tetrasulfonate groups, was synthesized and the morphology of the polymer, poly(HOAlIIItspc), in aqueous solutions was investigated using TEM, UV–vis absorption and emission spectroscopies. The strands of poly(HOAlIIItspc) are associated in near spherical bundles with ~150 nm diameter in aqueous solutions. Because of the size of the spheres, they must be aggregates of a large number of strands in a near spherical bundle. Most of the pendants in the bundles are forming p-stacks where the largest fraction of them must be dimers. CuII(tspc)4-and CoII(trspc)3- (tspc and trspc stand for the tetrasulphonated and trisulphonated- phthalocyanine, respectively), were covalently linked to a polyethyleneimine backbone. In order to ascertain the morphologies of poly(K2CoIItrspc) and poly(K3CuIItspc), TEM observations were made on various preparations of the polymers. Rosettes with ~1000 nm diameter were observed in the preparations of poly(K3CuIItspc). Smaller but similarly shaped structures with an average diameter of ~120 nm were observed in the preparations of poly(K2CoIItrspc). Because of the large size of these structures, they must be bundles of polymer strands which could be reminiscent of micelles in aqueous solution.