A micrometric silica modified with perylene derivative (SiO 2-TES) has been prepared by hydrolysis-condensation reactions between silica and N,N'-bis-(3-triethoxysilylpropyl)-perylene-tetracarboxyldiimide (P-TES) and utilized as filler in LLDPE films together with a compatibilizer. Spectroscopic analyses on SiO 2-TES confirmed the grafting of P-TES on silica, while its amount was determined by thermogravimetric analysis. Solid state NMR provided information about the structure of silicon atoms involved in the condensation of SiO 2 and P-TES that resulted mainly in silicon atoms grafted with bi-dentate anchorages. UV-Vis and fluorescence analyses carried out on P-TES showed the ability of the dye to generate J-type aggregates in apolar solvents. The same analyses on SiO 2-TES revealed the presence of both isolated and aggregated dye molecules grafted on silica surface, while on polymeric dispersions of SiO 2-TES, they have shown only the presence of P-TES aggregates grafted to silica. Thanks to the direct correlation between optical properties (obtained both by UV-Vis and by fluorescence analyses) and the chemical environment of composites, the luminescent silica SiO 2-TES could be used to estimate the filler dispersion extent in different microcomposite polymer materials. © 2011 Elsevier Ltd. All rights reserved.
Optical properties of a polyethylene dispersion with a luminescent silica prepared by surface grafting of a perylene derivative
RICCI, LUCIA;RUGGERI, GIACOMO;BORSACCHI, SILVIA;GEPPI, MARCO
2011-01-01
Abstract
A micrometric silica modified with perylene derivative (SiO 2-TES) has been prepared by hydrolysis-condensation reactions between silica and N,N'-bis-(3-triethoxysilylpropyl)-perylene-tetracarboxyldiimide (P-TES) and utilized as filler in LLDPE films together with a compatibilizer. Spectroscopic analyses on SiO 2-TES confirmed the grafting of P-TES on silica, while its amount was determined by thermogravimetric analysis. Solid state NMR provided information about the structure of silicon atoms involved in the condensation of SiO 2 and P-TES that resulted mainly in silicon atoms grafted with bi-dentate anchorages. UV-Vis and fluorescence analyses carried out on P-TES showed the ability of the dye to generate J-type aggregates in apolar solvents. The same analyses on SiO 2-TES revealed the presence of both isolated and aggregated dye molecules grafted on silica surface, while on polymeric dispersions of SiO 2-TES, they have shown only the presence of P-TES aggregates grafted to silica. Thanks to the direct correlation between optical properties (obtained both by UV-Vis and by fluorescence analyses) and the chemical environment of composites, the luminescent silica SiO 2-TES could be used to estimate the filler dispersion extent in different microcomposite polymer materials. © 2011 Elsevier Ltd. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
