ABSTRACT




	We have used porous inorganic materials as rigid matrices for encapsulating a series of organic conjugated polymers inside their pores. This preparative strategy aims at increasing the photostability, and O2 and moisture chemical resistance of the polymers, thus preserving their conducting, photochemical or optoelectronic properties. In all cases, the polymer has been prepared by in situ polymerization of suited monomer precursors, previously adsorbed inside the pores of inorganic matrices conveniently functionalized to contain the active polymerization sites. 
	As solid hosts, we have used X and Y faujasites, ITQ-2 delaminated zeolites, montmorillonite clays, MCM-41 mesoporous materials and monodisperse hollow spheres of amorphous silica. As organic polymeric guests, a number of selected ?-conjugated polymers have been prepared, attending to their electric conductivity or photochemical properties, and to their potential technologic applications. In particular, we have successfully synthesized: i) pure and 2,5-alkoxi substituted poly(p-phenylenevinylene) (PPV); ii) poly(2,6-naphthalenevinylene), a polymer analogous to PPV, but having a naphthalene instead of phenylene group intercalated to the vinylene chain; iii) a series of polyacetylene derivates containing naphthalene, phenanthrene, and thiophene pendant groups, as well as poly(diethynilbenzene), which has several polymerization possibilities that may be influenced by the geometry imposed by the matrix host; and iv) poly(ethylene dioxythiophene) (PEDOT). 
	PPV-modified polymers of groups i) and ii) are interesting because of their photochemical or electroluminescent properties, while the polyacetylenes (group iii) and PEDOT are known to be good electric conductors.
	For each individual case, the choice of the most appropriate inorganic matrix for each polymer has been made on the basis of the structure of the monomer precursor (electric charge and dimensions) and the polymerization mechanism (catalyzed by either base or Lewis acid sites). 
	The resulting organic-inorganic composite material has been thoroughly characterized by means of spectroscopic and analytical methods, with special attention to their photochemical (or electric conducting) properties and stability as compared to the non-encapsulated polymers. All the results obtained are consistent with the occurrence of polymerization, most likely inside the material pores. Noteworthy, our laser flash photolysis studies indicate that in general the inorganic matrix plays an active role in stabilizing the charge-separated states (polarons) formed upon irradiation of the encapsulated polymers. At the same time, the protective material also precludes diffusion of O2, H2O and other atmospheric pollutants from the environment, thus preventing deactivation of the polymer due to oxidative addition to unsaturated C-C bonds.