Intercalação de aminas em fenilfosfonatos e fenilarsonato metalicos lamelares : um enfoque termoquimico

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

The isostructural lamellar compounds titanium phenylphosphonate (FFT), titanium phenylarsonate (FAT) and zirconium phenylphosphonate (FFZ) were synthesized and intercalated with alkylmonoamines (methyl- to heptylamines), alkyldiamines (diaminoethane and diaminobuthane) and aromatic amines (lutidine and a-picoline). They were characterized through ele mental analysis, X ray diffraction, P nuclear magnetic resonance in the solid state, surface analysis, porosity, infrared spectroscopy, thermogravimetry and electronic scanning microscopy. Batch adsorption studies and characterization techniques showed that the matrices were destroyed during the intercalation process and the X ray diffractograms did not show significant increases in the interlamellar distances. The intercalation was confirmed by a thermogravimetric technique that indicated the mass loss intervals and also by scanning electronic microscopy, which showed modification of the matrices morphology. The ideal intercalation was established by adding increments of 30.0 mL of 0.50 mol dm amine into 10.0 mg of the matrices in alkylmonoamines suspension. The number of moles intercalated with alkylmonoamines and alkyldiamines followed an aleatory order in relation to the increase of the aliphatic chain, as the enthalpic values gave -16.19±0.22; -18.72±0.19; -23.72±0.24; -18.31±0.22; -9.20±0.16; -10.17±0.10; -15.14±0.30 kJ mol for alkylmonoamines and -10.27±1.40; -9.48±1.50 kJ mol for alkyldiamines, when intercalated in FFT. Similar behavior with FAT and FFZ was also observed. With aromatic amines the thermal effect did not detect a significant value for intercalation, which is attributed to the large volume of the phenyl group in the interior of the lamella.

ASSUNTO(S)

aminas calorimetria

ACESSO AO ARTIGO

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