Multifunctional organic–inorganic hybrids based on cellulose acetate and 3-glycidoxypropyltrimethoxysilane

Abstract

Organic–inorganic hybrid films have been prepared from cellulose acetate (CA) and 3-glycidoxypropyltrimethoxysilane (GPTMS). Flexible films were fashioned with high relative content of GPTMS (up to 70 wt%) and exhibited high transparency in the visible/near-infrared region. The atomic force microscopy images of hybrid films display the presence of nanometric globular-like domains with size dependent and number dependent of the content of GPTMS. X-ray diffraction (XRD) patterns showed decreasing crystallinity of CA hybrid counterpart with increasing amounts of GPTMS. Spectroscopy results (vibrational spectroscopy FTIR and Raman scattering, 13C and 29Si NMR spectra) suggest that epoxy groups mostly remain intact and significant amount of methoxysilane groups is available after addition of GPTMS in CA. From 29Si NMR results, all compositions showed the presence of non-hydrolized GPTMS molecules or having mono- and disubstituted siloxane bonds. For highest relative content of GPTMS (i.e., 50 wt%), a considerably high amount of non-hydrolized (T0) is observed. Moreover, the addition of GPTMS leads to an increase in the thermal stability as compared to pure CA. Luminescent films were obtained by incorporating luminescent [Eu(TTA)3(H2O)2] complex (TTA = thenoyltrifluoroacetonate) into the hybrid films. Spectroscopic parameters did not significantly change with the incorporation of luminescent complex, suggesting application in photonics. The 5D0 states quantum efficiency was observed to be the same for the neat complex and the luminescent hybrid film, suggesting a weak interaction with the host.