Thermostructural and fluorescence properties of enterolobium cyclocarpum extract embedded in a silica xerogel matrix

Abstract

This work deals with the fluorescence behavior exhibited by extracts of parota wood (enterolobium cyclocarpum) when are embedded in a silica matrix, and the effect of the temperature on the emission and structural properties. The organics were incorporated into a silica matrix using the sol-gel method, and the resulting hybrid composite was subjected to different heat treatments to study its thermal stability and the effect on their structural and fluorescence properties. The structural properties were studied using x-ray diffraction (XRD), and the organics were analyzed by infrared spectroscopy (FT-IR) and fluorescence spectroscopy. Results show that the silica matrix avoids the thermal decomposition of the organics, and the structural changes of the silica impact on the fluorescence properties. In this sense, the maximum emission obtained at 400 °C was three times higher than the RT. This behavior was attributable to the strong interactions between the cellulosic compounds and the silica. Also, the cellulosic compounds promote the formation of open Si-O arrangements.

Keywords

• parota extracts
• cellulose chains
• fluorescence emission
• hybrid composite
• silica structure