Sinthesys of polypyrrole onto Na-AlSBA-3 naostructured material: a composite for potential applications in electronic devices

OSCAR A. ANUNZIATA; MARÍA L. MARTÍNEZ; MARCOS GÓMEZ COSTA

Singapur

Conferencia; 1st NanoToday Conference; 2009

nanotoday

In the last decade, there has been increasing interest in the development of mesoporous silica-supported nanocomposites due to heir potential applications in catalysis, as well as miniaturized electronic and optical device. Encapsulation of conducting polymer can improve the mechanical, thermal and chemical stability of the assemblies, and possibly allowing individual molecular wires to be addressed. Polypyrrole (PPy), has been widely studied because of its high polarizability and conductivity. Due to the different precipitation conditions and charge balance requirements for its preparation, the acid-derived materials, i.e., SBA´s [1], contain thicker pore walls and a framework charge different than from the base-derived mesoporous materials. For instance, the overall framework charge of SBA-3 (acidic condition) was slightly positive whereas the framework of MCM-41(basic condition) was negative. The mesoporous silica, Na-Al-SBA-3, was synthesized according to our recent report [2], where sodium aluminate was added during the formation of the mesophase. Pyrrole in gas phase was adsorbed into the pores of the host at 120 ºC for 72 h, and subsequently pyrrole containing-Na-Al-SBA-3 was immersed in acidic aqueous solution, then ammonium peroxydisulfate is added. The PPy/Na-Al-SBA-3 obtained was washed and dried. The XRD and FTIR spectroscopy were made. According to the low angle XRD pattern (2θ=1.5-7º), the characteristic peaks of mesoporous materials is observed in Na-Al-SBA-3. In the FTIR spectra, the PPy/Na-Al-SBA-3 differs from the host material in several ways. Thus, for PPy/Na-Al-SBA-3 the absorption band at 1547 cm-1 is associated with C-C stretching vibrations, the bands at 1458 cm-1 represents C-N stretching vibrations and the bands at 783 cm-1 and 669 cm-1 correspond to C-H outer-bending vibrations.  The FTIR spectra of the nanocomposites confirm the incorporation of PPy inside the channels of Na-Al-SBA-3. [1]O.A. Anunziata, A.R.Beltramone, M.L.Martinez, L.LópezBelón. J. of Coll. and Interf. Scie. 315(2007)184–190 [2]M.L.Martínez, O.A. Anunziata, to be published, Mat. Lett.(2009)